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دسترسی آزاد مقاله
1 - Estimation of lattice strain in ZnO nanoparticles: X-ray peak profile analysis
P. Bindu Sabu ThomasAbstractZnO nanoparticles were synthesized from chitosan and zinc chloride by a precipitation method. The synthesized ZnO nanoparticles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction peak profile analysis, Scanning electron microscopy, چکیده کاملAbstractZnO nanoparticles were synthesized from chitosan and zinc chloride by a precipitation method. The synthesized ZnO nanoparticles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction peak profile analysis, Scanning electron microscopy, Transmission electron microscopy and Photoluminescence. The X-ray diffraction results revealed that the sample was crystalline with a hexagonal wurtzite phase. We have investigated the crystallite development in ZnO nanoparticles by X-ray peak profile analysis. The Williamson–Hall analysis and size–strain plot were used to study the individual contributions of crystallite sizes and lattice strain ϵ on the peak broadening of ZnO nanoparticles. The parameters including strain, stress and energy density value were calculated for all the reflection peaks of X-ray diffraction corresponding to wurtzite hexagonal phase of ZnO lying in the range 20°–80° using the modified form of Williamson–Hall plots and size–strain plot. The results showed that the crystallite size estimated from Scherrer’s formula, Williamson–Hall plots and size–strain plot, and the particle size estimated from Transmission electron microscopy analysis are very much inter-correlated. Both methods, the X-ray diffraction and Transmission electron microscopy, provide less deviation between crystallite size and particle size in the present case. پرونده مقاله -
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2 - Investigation of sensitivity and selectivity of ZnO thin film to volatile organic compounds
F. Teimoori K. Khojier N. Z. DehnaviAbstractThis research addresses a detailed study on the sensitivity and selectivity of ZnO thin film to volatile organic compound (VOC) vapors that can be used for the development of VOC sensors. The ZnO thin film of 100 nm thickness was prepared by post-annealing of e- چکیده کاملAbstractThis research addresses a detailed study on the sensitivity and selectivity of ZnO thin film to volatile organic compound (VOC) vapors that can be used for the development of VOC sensors. The ZnO thin film of 100 nm thickness was prepared by post-annealing of e-beam evaporated Zn thin film. The sample was structurally, morphologically, and chemically characterized by X-ray diffraction and field emission scanning electron microscopy analyses. The sensitivity, selectivity, and detection limit of the sample were tested with respect to a wide range of common VOC vapors, including acetone, formaldehyde, acetic acid, formic acid, acetylene, toluene, benzene, ethanol, methanol, and isopropanol in the temperature range of 200–400 °C. The results show that the best sensitivity and detection limit of the sample are related to acetone vapor in the studied temperature range. The ZnO thin film-based acetone sensor also shows a good reproducibility and stability at the operating temperature of 280 °C. پرونده مقاله -
دسترسی آزاد مقاله
3 - In vitro bioactivity of silicophosphate glasses doped with ZnO, SrO or CuO
H. A. ElBatal A. A. El-Kheshen M. A. Marzouk N. A. Ghoneim F. H. ElBatal M. A. Ouis A. M. Fayad A. M. AbdelghanyAbstractSilicophosphate glasses with variable divalent ion dopants (Zn2+, Sr2+ or Cu2+) were prepared via melt annealing route. Parent and doped glasses were thermally heat-treated through a two-step regime to be converted into their glass–ceramic derivatives. Fourier t چکیده کاملAbstractSilicophosphate glasses with variable divalent ion dopants (Zn2+, Sr2+ or Cu2+) were prepared via melt annealing route. Parent and doped glasses were thermally heat-treated through a two-step regime to be converted into their glass–ceramic derivatives. Fourier transform infrared (FT-IR) spectral data were recorded for parent glasses and their glass–ceramics derivatives to identify the structural building units which reveal vibrational bands due to both main phosphate and some silicate groups and to verify the bioactivity behavior after immersion in diluted phosphate solution. X-ray diffraction studies indicate the formation of different phosphate and silicate crystalline phases in the derived glass–ceramics which varied with the type of dopant oxide. SEM investigations of the glass–ceramics before and after immersion in phosphate solution showed multicomponent microcrystalline textures in the studied micrographs before immersion. Nodular-shaped microcrystalline features were identified after immersion in phosphate solution referring to the formation of crystalline hydroxyapatite. The undoped glass–ceramic is identified to crystallize in almost equal silicate and phosphate phases, while with the dopant ZnO, SrO or CuO, the crystalline phases are only of phosphates, while the silicate phase is assumed to be retained in the surrounding remaining vitreous boundaries. پرونده مقاله -
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4 - Effect of Eu doping on the structure, morphology and luminescence properties of ZnO submicron rod for white LED applications
Mei XinAbstractEu3+-doped ZnO submicron rod has been prepared by a hydrothermal method. Synthesized rods are characterized by X-ray diffraction, scanning electron microscopy and photoluminescence spectra (PL). The results indicated structures and morphology of rods affected by چکیده کاملAbstractEu3+-doped ZnO submicron rod has been prepared by a hydrothermal method. Synthesized rods are characterized by X-ray diffraction, scanning electron microscopy and photoluminescence spectra (PL). The results indicated structures and morphology of rods affected by the Eu3+ doping concentration. 5D0–7FJ (J = 1, 2 and 3) of Eu3+ emission appeared, and energy transfer from the ZnO host and deep defects of ZnO to Eu3+ in the ZnO:Eu is occurred. Strong and white emission was observed in the sample with 15% Eu. پرونده مقاله -
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5 - Investigation of ZnO thin-film sensing properties for CO2 detection: effect of Mn doping
Boshra Ghanbari Shohany Leili Motevalizadeh Majid Ebrahimizadeh AbrishamiAbstractA simple spray pyrolysis technique has been used to fabricate ZnO/Mn thin films with different Mn concentrations (0, 5, 10 and 15 mol.%) for gas sensing applications. X-ray diffraction (with Cu-Kα radiation) patterns of the samples revealed the formation of sing چکیده کاملAbstractA simple spray pyrolysis technique has been used to fabricate ZnO/Mn thin films with different Mn concentrations (0, 5, 10 and 15 mol.%) for gas sensing applications. X-ray diffraction (with Cu-Kα radiation) patterns of the samples revealed the formation of single-phase wurtzite structure. The samples were characterized using field-emission scanning electron microscopy and scanning tunneling microscopy. The investigation revealed that the surface of pure ZnO thin film appears rougher and containing bigger grains. The response of the pure and Mn-doped ZnO thin-film gas sensors was checked at different temperatures ranging from 120 up to 200 °C, to investigate the optimum sensing efficiency. The gas sensing results have demonstrated that the pure ZnO thin film exhibited higher sensitivity to CO2 gas at 150 °C operating temperature, while the sensitivity reduced with the increase in gas pressure. Although the sensitivity of doped samples was lower than the pure sample, the sensitivity increased with the increase in pressure. پرونده مقاله -
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6 - Synthesis, structural and optical properties of pure ZnO and Co doped ZnO nanoparticles prepared by the co-precipitation method
P. Geetha Devi A. Sakthi VeluAbstractPure ZnO and Cobalt (Co) doped ZnO nanoparticles (NPs) were synthesized by the co-precipitation method. The synthesized nanoparticles retained the wurtzite hexagonal structure, which was confirmed by X-ray diffraction studies. From FESEM studies, ZnO and Co dope چکیده کاملAbstractPure ZnO and Cobalt (Co) doped ZnO nanoparticles (NPs) were synthesized by the co-precipitation method. The synthesized nanoparticles retained the wurtzite hexagonal structure, which was confirmed by X-ray diffraction studies. From FESEM studies, ZnO and Co doped ZnO NPs showed Spherical and nanorod mixed phase and Spherical like morphology, respectively. The amount of dopant (Co2+) incorporated into ZnO sample was determined by EDAX. The FT-IR spectra confirmed the Zn–O stretching bands at 438 and 427 cm−1 for ZnO and Co doped ZnO NPs. From the UV–VIS spectroscopic measurements, the excitonic pecks were found around 376 and 370 nm for the respective samples. The photoluminescence measurements revealed that the broad emission was composed of seven different bands due to zinc vacancies, oxygen vacancies and surface defects. The dynamic light scattering (DLS) and Zeta potential measurements were used to find out the size and surface charges. پرونده مقاله -
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7 - Multiple-layered structure of obelisk-shaped crystalline nano-ZnO prepared by sol–gel route
Saeideh Jurablu Majid Farahmandjou Tahereh Pormirjaafari FiroozabadiAbstractZinc oxide nanopowders were synthesized by the simple sol–gel method from an ethanol solution of zinc nitrate hexahydrate. Structural and surface morphological investigations were carried out using X-ray diffraction (XRD), high-resolution transmission electron m چکیده کاملAbstractZinc oxide nanopowders were synthesized by the simple sol–gel method from an ethanol solution of zinc nitrate hexahydrate. Structural and surface morphological investigations were carried out using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) and ultraviolet–visible (UV–Vis) spectrophotometry analyses. XRD pattern showed that the zinc oxide nanoparticles exhibited hexagonal wurtzite structure. A multiple-layered structure of obelisk-shaped ZnO nanoparticles was achieved after calcinations. The average particle size of ZnO was around 20 nm as estimated by direct HRTEM observation. The size of sphere-like shaped ZnO nanoparticles was measured in the range of 20–80 nm and the size of pyramid-like shaped annealed samples was achieved in the range of 40–100 nm with less agglomeration. The energy dispersive spectroscopy spectrum showed peaks of zinc and oxygen. The sharp peaks in FTIR spectrum determined the Zn–O stretching and absorbance peak of UV–Vis spectrum showed the wide bandgap energy of 3.35 eV. پرونده مقاله -
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8 - Investigating the effect of geometrical asymmetry on conductance and TMR ratio in the ZnO rock salt-based MTJ: a DFT study
Masoud AnsarinoAbstractEffects of geometrical asymmetry on spintronic properties of Fe/ZnO/Fe magnetic tunnel junction based on zinc oxide barrier tunnel with rock-salt crystalline structure is studied. Simulations are performed using density functional theory, and substituted layers چکیده کاملAbstractEffects of geometrical asymmetry on spintronic properties of Fe/ZnO/Fe magnetic tunnel junction based on zinc oxide barrier tunnel with rock-salt crystalline structure is studied. Simulations are performed using density functional theory, and substituted layers of C, Mg, Al, Mo, and Ta are used to make geometrically asymmetric structures. The results indicate that this asymmetry has a substantial influence on the properties of the spin-dependent electronic transport, conductance, and the tunneling magneto-resistance (TMR) ratio of the pristine symmetric structure. Additionally, it is shown that geometrical asymmetry results in a sharp decrease in the TMR ratio in one of these junctions and causes a negative TMR ratio in the other four asymmetric structures. Due to the large conductance of the three pristine, C and Al substituted structures in the PA configuration, these structures can be used to generate the current with pure spin for experimental purposes. پرونده مقاله -
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9 - Rapid growth of zinc oxide nanobars in presence of electric field by physical vapor deposition
Mehraban Jouya Fahime Taromian Simin SiamiAbstractIn this contribution, electric field has some effects to increase growth for specific time duration on zinc oxide (ZnO) nanobars. First, the zinc (Zn) thin film has been prepared by 235,000 V/m electric field assisted physical vapor deposition (PVD) at vacuum of چکیده کاملAbstractIn this contribution, electric field has some effects to increase growth for specific time duration on zinc oxide (ZnO) nanobars. First, the zinc (Zn) thin film has been prepared by 235,000 V/m electric field assisted physical vapor deposition (PVD) at vacuum of 1.33 × 10−5 mbar. Second, strong electric field of 134,000 V/m has been used in ambient for growing ZnO nanobars in term of the time include 2.5 and 10 h. The performances of the ZnO nanostructure in absence and presence of electric field have been determined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results of XRD analysis showed that ZnO has a hexagonal bars structure and a strongly preferred (101) orientation which is strongest than without applying electric field. SEM analysis revealed that physical vapored ZnO thin film in presence of electric field are densely packed with uniform morphological, thinner and denser in distribution. Electric field effect for ZnO growth in 2.5 h is better than it in the 2.5 h without electric field but by passing the time the media influence has good power almost as same as electric field. Through this electric field in PVD, the compact and uniform Zn film has been achieved which is less diameter than ordinary PVD method. Finally, we carry out a series of experiments to grow different-orientation ZnO nanobars with less than 100 nm in diameter, which are the time saving process in base of PVD ever reported. Therefore, the significant conclusion in usage electric field is reducing time of growth. پرونده مقاله -
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10 - Investigation morphological, electrical, and optical properties of Mn-doped ZnO thin film by sol–gel spin-coating method
Mehmet ÇavaşAbstractIn this study, ZnO was doped with 0.01% Mn and it is grown on p-Si by the sol–gel spin-coating method. Obtained the thin film was studied that to understand the effect of 0.01% Mn-doping ratio on the optical and electrical properties of ZnO structure. In this co چکیده کاملAbstractIn this study, ZnO was doped with 0.01% Mn and it is grown on p-Si by the sol–gel spin-coating method. Obtained the thin film was studied that to understand the effect of 0.01% Mn-doping ratio on the optical and electrical properties of ZnO structure. In this context, first, the morphological structure of the thin film was studied with the use of atomic force microscopy (AFM). The surface structure was obtained homogeneous, and roughness and fiber size were calculated between 27.2–33.6 and 0.595–0.673 nm, respectively. Second, the optical properties were characterized via ultraviolet–visible (UV–Vis) spectrophotometry. Third, the effect of light intensity on junction properties of the photodiode was studied. The current–voltage (I–V) of the photodiode was measured under dark and at the different intensities of illumination. Obtained results showed that the current of photodiode was increased with the intensity of illumination from 6.41 × 10−7 to 5.32 × 10−4 A. These results indicate that photocurrent under illumination is higher than the dark current. After that, the other parameters of the photodiode such as barrier height and ideality factor were determined from forwarding I–V plots using the thermionic emission model that the barrier height and the ideality factor were found 0.74 eV and 5.3, respectively. On the other hand, the capacitance–voltage (C–V) was measured at the different frequencies. The C–V characteristic shown that C–V characteristic of the photodiode was changed depends on increasing frequency. In addition, the interface density (Dit) value was decreased by increasing frequency too. Similarly, the serial resistance of the photodiode was also decreased by increasing frequency. Received all these results indicated that Mn-doped ZnO thin film sensitive to light and due to this property, it can be used for different optoelectronic applications as a photodiode and photosensor. پرونده مقاله -
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11 - The effects of multiwall carbon nanotubes on the electrical characteristics of ZnO-based composites
N. Asaadi M. Parhizkar H. Bidadi S. Mohammadi Aref M. GhafouriAbstractIn this experimental work, the effects of multiwall carbon nanotubes (MWCNTs) on electrical characteristics of zinc oxide–MWCNT–high-density polyethylene composite varistors have been investigated. All the samples were made at the temperature of 130 °C and press چکیده کاملAbstractIn this experimental work, the effects of multiwall carbon nanotubes (MWCNTs) on electrical characteristics of zinc oxide–MWCNT–high-density polyethylene composite varistors have been investigated. All the samples were made at the temperature of 130 °C and pressure of 60 MPa by the hot-press method. Results show that increasing zinc oxide content in the mixture increases breakdown voltage up to 170 V, where the highest nonlinear coefficient (α ~ 13) corresponds to the samples with 95 wt% of ZnO. Results with regard to the effects of MWCNT as an additive reveal that increasing its content from 1 to 2.5% in the composites, the breakdown voltage decreases to 50 V, but the highest nonlinear coefficient (~ 14) corresponds to the sample with 1.5% of MWCNT content. It is also revealed that, heat treatment of the sample at a constant temperature of 135 °C and different time intervals from 2 to 10 h, the sample with 6 h annealing time shows maximum breakdown voltages (Vb = 140 V) with the highest nonlinear coefficient (~ 14). Investigation of the potential barrier height of samples shows a complete consistency with the breakdown voltage variations. The results have been justified regarding XRD patterns and SEM micrographs of samples. پرونده مقاله -
دسترسی آزاد مقاله
12 - Fabrication of Au/ZnO/MWCNTs electrode and its characterization for electrochemical cholesterol biosensor
Davood Ghanei Agh Kaariz Elham Darabi Seyed Mohammad ElahiAbstractIn this work, a new sensitive enzyme-based electrode for electrochemical cholesterol biosensor was fabricated based on a nanocomposite of Au nanoparticles, ZnO nanoparticles and multi-wall carbon nanotubes (Au/ZnO/MWCNTs). The nanocomposite was prepared by sol–g چکیده کاملAbstractIn this work, a new sensitive enzyme-based electrode for electrochemical cholesterol biosensor was fabricated based on a nanocomposite of Au nanoparticles, ZnO nanoparticles and multi-wall carbon nanotubes (Au/ZnO/MWCNTs). The nanocomposite was prepared by sol–gel method and deposited on FTO substrate by dip coating, followed by cholesterol oxidase (ChOx) enzyme immobilized (ChOx/Au/ZnO/MWCNTs). Structural properties and morphology of the nanocomposite have been studied using X-ray diffraction (XRD) and Field emission scanning electron microscopy (FESEM). The sample was subjected to Fourier transform infrared spectroscopy (FTIR) to determine functional groups. Electrochemical behavior of the electrode was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques as a function of cholesterol concentration. Electrochemical impedance spectroscopy (EIS) was also considered to study of surface modified electrodes. The ChOx/Au/ZnO/MWCNTs electrode has been found to have enhanced electron transfer and display excellent analytical linear performances. The fabricated electrode exhibited low detection limit (0.1 μM), high sensitivity (25.89 μA/μM) evaluated from DPV data in the detection range of 0.1–100 µM and high selectivity in the determination of cholesterol over glucose and uric acid. The application of the ChOx/Au/ZnO/MWCNTs electrode in detection of cholesterol in human serum was also confirmed. پرونده مقاله -
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13 - Density functional theory study on the effect of Cu- and Na-substituted layers on spin-dependent transport and TMR in the Fe/ZnO/Fe MTJ
Masoud AnsarinoAbstractUsing density functional theory, effects of Na- and Cu-substituted layers on the spin-dependent electronic transport properties of Fe/ZnO/Fe magnetic tunnel junction based on zinc oxide barrier tunnel, with rock-salt crystalline structure, have been studied. In چکیده کاملAbstractUsing density functional theory, effects of Na- and Cu-substituted layers on the spin-dependent electronic transport properties of Fe/ZnO/Fe magnetic tunnel junction based on zinc oxide barrier tunnel, with rock-salt crystalline structure, have been studied. In zero-bias voltage, conductance and tunneling magneto-resistance (TMR) ratio of structures are calculated. It is showed that substituted layers in the pristine junction greatly affect conductance and TMR ratio of this junction. The results indicated that Cu-substituted layer with reducing conductance of pristine structure in the antiparallel alignment configuration, and increasing its conductance in the parallel alignment, leads to a large TMR ratio, up to 1800%. Due to the large conductance of pristine and Cu-substituted devices in the parallel alignment, these structures would be very beneficial for experimental applications that require the spin-polarized current. پرونده مقاله -
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14 - Decontamination of DMMP by adsorption on ZnO, A Computational Study
F. R. Nikmaram J. Najafpour M. Ashrafi ShahriAb initio calculations at the density functional theory (DFT) and the second-order Møller−Plessetperturbation theory levels with 6-31+G(d), 6-31G(d) basis sets for non-metal atoms and LANL2DZfor metal have been performed for the adsorption of dimethyl methy چکیده کاملAb initio calculations at the density functional theory (DFT) and the second-order Møller−Plessetperturbation theory levels with 6-31+G(d), 6-31G(d) basis sets for non-metal atoms and LANL2DZfor metal have been performed for the adsorption of dimethyl methylphosphonate (DMMP) on ZnOby Gaussisn 98 program. The calculated rotational constants by B3LYP/6-31G(d) are in moreagreement with the experimental values. The type of interaction between the Zn from ZnO andphosphoryl group from DMMP is estimated by AIM analysis. The molecular adsorption occurs byvan der waals interaction of Zn⋯O=With one Hydrogen bonding, between CH3 groups andoxygen of zinc oxide. پرونده مقاله -
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15 - Photocatalytic degradation of Lidocaine HCl using CuO/ZnO nanoparticles
N. Badalpoor M. Giahi S. HabibiIn this paper, the photocatalytic degradation of Lidocaine HCl, an anesthetic was investigated inaqueous solution using CuO/ZnO as a photocatalyst. The degradation was studied under differentconditions including the amount of the photocatalyst, irradiation time, initial چکیده کاملIn this paper, the photocatalytic degradation of Lidocaine HCl, an anesthetic was investigated inaqueous solution using CuO/ZnO as a photocatalyst. The degradation was studied under differentconditions including the amount of the photocatalyst, irradiation time, initial concentration of drug,pH of the system, initial concentration, addition of oxidant on the reaction rate and anion presence.The results showed that the photocatalytic degradation of Lidocaine HCl was strongly influenced bythese parameters. The best conditions for the photocatalytic degradation of Lidocaine HCl wereobtained. The optimum amount of the photocatalyst used is 0.48 g/L. The photodegradationefficiency of Lidocaine HCl increases with the increase of the illumination time. It was found that thephotodegradation efficiency decreased with increasing the initial concentration of Lidocaine HCl.The photodegradation efficiency of Lidocaine HCl was accelerated by adding a small amount ofH2O2. The possible roles of the additives on the reactions and the possible mechanisms of effect werealso discussed. پرونده مقاله -
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16 - Photochemical Studies on Degradation of Cetyl Pyridinium Chloride (Cationic Surfactant) in Aqueous Phase Using Different Photocatalysts
A. Moradidoost M. Giahi M. A. BagheriniaThe photocatalytic process using semiconductors with a nanostructure is one of the technologies usedfor the destructive oxidation of organic compounds such as surfactants. In this paper, thephotocatalytic degradation of Cetyl pyridinium chloride (CPC), was investigated چکیده کاملThe photocatalytic process using semiconductors with a nanostructure is one of the technologies usedfor the destructive oxidation of organic compounds such as surfactants. In this paper, thephotocatalytic degradation of Cetyl pyridinium chloride (CPC), was investigated in aqueous phaseusing various semiconductors such as titanium dioxide (Ti02), zinc oxide (ZnO), stannic oxide(Sn02). The degradation was studied under different conditions including the amount ofphotocatalyst, pH of the system, initial concentration and presence of anions. The results showed thatthe photocatalytic degradation of CPC was strongly influenced by these parameters and the bestconditions for the photocatalytic degradation of CPC were obtained. The experimental resultsindicated that maximum degradation (87%) of surfactant occurred when ZnO was used as catalyst.The photodegradation efficiency was enhanced by increasing amount of photocatalyst, and decreaseswith the increase in the initial concentration of Cetyl pyridinium chloride. Finally, the kineticsprocess was studied and the photodegradation rate of CPC was found to obey pseudo-first-orderkinetics equation represented by the Langmuir—Hinshelwood model. پرونده مقاله -
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17 - Adsorption of thallium (III) ion from aqueous solution using modified ZnO nanopowder
H. Dashti Khavidaki H. Aghaie M. R. ShishehboreIn this study, the adsorption of thallium (III) ion from aqueous solutions onto modified ZnOnanopowder as a fairly low cost adsorbent has been investigated in batch mode. It was found thatmodification of the adsorbent was essential for obtaining the significant adsorpti چکیده کاملIn this study, the adsorption of thallium (III) ion from aqueous solutions onto modified ZnOnanopowder as a fairly low cost adsorbent has been investigated in batch mode. It was found thatmodification of the adsorbent was essential for obtaining the significant adsorption percentage. Theadsorbent modified by sodium phosphate solution. The effect of experimental parameters such asinitial pH of solution, contact time, adsorbent dosage, thallium initial concentration and temperaturewas studied. The results showed that the adsorption percentage was dependent on this parametersspecially pH. The successful adsorption percentage of thallium (III) ion obtained at 25±1°C was 92.2-92.6%. The equilibrium data could be well described by the Freundlich isotherm but its fitting byLangmuir model was not so successful. Separation factor, RL, values showed that modified ZnOnanopowder were favorable for the sorption of thallium (III) ion. پرونده مقاله -
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18 - تاثیر فیلمهای کامپوزیتی نانولوله کربنی و نانوذرات اکسیدروی بر خواص حسی و آلودگی میکروبی خرمای مضافتی
‍‍‍‍‍‍بریناز عسگری امید مرادی بهجت تاج الدینمقدمه: خرما یکی از محصولات بسیار مهم ایران است که نقش مهمی در تغذیه مردم دارد. حدود 35 درصد از میزان کل خرمای تولیدی کشور به دلایل مختلف از جمله بسته بندی نامناسب، غیر علمی و غیر بهداشتی به ضایعات تبدیل می گردد که با توجه به ارزش اقتصادی این محصول، همچنین اهمیت نانوتکنو چکیده کاملمقدمه: خرما یکی از محصولات بسیار مهم ایران است که نقش مهمی در تغذیه مردم دارد. حدود 35 درصد از میزان کل خرمای تولیدی کشور به دلایل مختلف از جمله بسته بندی نامناسب، غیر علمی و غیر بهداشتی به ضایعات تبدیل می گردد که با توجه به ارزش اقتصادی این محصول، همچنین اهمیت نانوتکنولوژی در افزایش کارایی بسته بندی در نگهداری موادغذایی، اثر فیلم های کامپوزیتی نانولوله کربنی و نانوذرات اکسیدروی بر روی خواص حسی و آلودگی میکروبی خرمای مضافتی بررسی شد. مواد و روشها: خرمای مضافتی از بازار تهران خریداری گردید و در بسته های پلی اتیلنی خالص (نمونه شاهد، w) و فیلم های حاوی نانو لوله های کربنی و نانو ذرات اکسیدروی (CZ)، در سه سطح (2، 1 و 1/0 درصد) بسته بندی و در فواصل زمانی 90 روزه مورد آزمون واقع شد. نتایج با استفاده از آزمون چند دامنه ای دانکن مورد ارزیابی قرار گرفت. یافتهها: مشخص شد که بار میکروبی، در صورت استفاده از فیلم های کامپوزیتی نانولوله کربنی و نانوذرات اکسیدروی، به طور معنی داری کاهش می یابد، در واقع تعداد باکتریهای لاکتیکی در نمونه حاوی نانولوله کربنی و نانو ذرات اکسید روی در سطح 2 درصد 83/0 سیکل لگاریتمی کاهش نشان داد. نتیجهگیری: نتایج نشان داد، در صورت استفاده از فیلم فوق می توان مدت ماندگاری خرمای مضافتی را بدون اثر نامطلوب بر روی ویژگی های حسی افزایش داد. در این پژوهش، بهترین نتیجه مربوط به فیلم های ترکیبی نانولوله کربنی و نانوذرات اکسیدروی با 2 درصد اکسیدروی (1CZ) می باشد. پرونده مقاله -
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19 - استفاده از اسانس شوید همراه با نانوذرات اکسید روی در ساختار پوشش فعال برپایه کربوکسی متیل سلولز جهت افزایش عمرماندگاری میگو تحت شرایط یخچال
سویل تکلوی تکتم مستقیم شهلا شهریاریمقدمه: در میان مواد غذایی دریایی، میگو یکی از بیشترین تقاضاها در تجارت جهانی را دارا می باشد. با این وجود، میگو نسبت به فساد وتغییرات بیوشیمیایی، میکروبیولوژیکی یا فیزیکی پس از صید بسیار آسیب پذیر است، که منجر به زمان ماندگاری محدود محصول می شود.هدف از این تحقیق، بهبود چکیده کاملمقدمه: در میان مواد غذایی دریایی، میگو یکی از بیشترین تقاضاها در تجارت جهانی را دارا می باشد. با این وجود، میگو نسبت به فساد وتغییرات بیوشیمیایی، میکروبیولوژیکی یا فیزیکی پس از صید بسیار آسیب پذیر است، که منجر به زمان ماندگاری محدود محصول می شود.هدف از این تحقیق، بهبود زمان ماندگاری میگوی صید شده از دریا می باشد.مواد و روش ها: در این پژوهش تولید پوشش خوراکی فعال برپایه کربوکسی متیل سلولز ( CMC) حاوی نانوذرات اکسید ( ZnO ) روی(0.03 درصد) و اسانس شوید با سطوح 0 ، 1 ، 2 ، 3 و 4 درصد به عنوان نگهدارنده طبیعی به منظور افزایش ماندگاری میگو در طول 12روز نگهداری در دمای یخچال صورت گرفت.یافته ها: استفاده از پوشش خوراکی فعال برپایه CMC منجر به کاهش تغییرات pH نمونه های میگوی پوشش داده شده در طول دورهنگهداری گردید، به طوری که پوشش حاوی نانوذرات ZnO و 4 درصد اسانس شوید تاثیر بیشتری داشت و باعث افزایش زمان نگهداری بهطور معنی داری (0.05>P) شده و محتوی مواد نیتروژن دار فرار کل را تا پایان دوره نگهداری 12 روزه افزایش داد، اما استفاده از نانوذراتZnO و افزایش غلظت اسانس شوید از 0 تا 4 درصد منجر کاهش معنی دار(0.05>P) محتوی مواد نیتروژن دار فرار کل شد. اگرچهبکارگیری اسانس شوید در مقایسه با نمونه شاهد به طور معنی داری (0.05>P) کL* را کاهش و b را افزایش داد، اما در طول دوره نگهداری نمونه های تیمار شده با سطوح بالاتر اسانس شوید تغییرات رنگی کمتری داشتند. با این وجود افزایش زمان نگهداری به طور معنی داری(0.05>P)شاخص b را افزایش و L*نمونه های میگو را کاهش داد. افزایش زمان نگهداری باعث کاهش معنی دار(0.05>P) سفتینمونه های میگو شد اما استفاده از نانوذرات و اسانس روند نرم شدن نمونه های میگو را کاهش دادند. شمارش باکتری های هوازی،اشریشیاکلای و استافیلوکوکوس اورئوس کواگولاز مثبت نشان داد تعداد میکروارگانیسم ها وابسته به حضور نانوذرات و غلظت اسانس برایتیمار نمودن نمونه ها و همچنین مدت زمان نگهداری بود. استفاده از سطوح بالای اسانس منجر به افزایش معنی داری(0.05>P) امتیازپارامترهای حسی می شود به طوری که تیمار حاوی 3 درصد اسانس شوید بالاترین پذیرش کلی را داشت. نتیجه گیری: استفاده از 3 درصد اسانس شوید به عنوان نگهدارنده طبیعی همراه با نانوذرات ZnO در ساختار پوشش خوراکی فعال برپایهCMC برای نگهداری میگو در دمای یخچال توصیه می شود. پرونده مقاله -
دسترسی آزاد مقاله
20 - بررسی حذف زایلن از آب به وسیله نانو اکسید روی به عنوان جاذب نفت
بهناز صالحی امیرحسام حسنی همایون احمد پناهی سید مهدی برقعیزمینه و هدف : با توجه به اثرا ت نا مطلوب زیست محیطی و خسارات غیر قابل جبران مواد شیمیایی موجود در ترکیبات نفتی نظیر بنزن، تولوئن ، اتیل بنزن و زایلن بر سلامت جانداران، حذف موثر و کارامد این آلاینده ها بیش از پیش مورد توجه قرار گرفته است تا با ابداع روش های نوین کارایی و چکیده کاملزمینه و هدف : با توجه به اثرا ت نا مطلوب زیست محیطی و خسارات غیر قابل جبران مواد شیمیایی موجود در ترکیبات نفتی نظیر بنزن، تولوئن ، اتیل بنزن و زایلن بر سلامت جانداران، حذف موثر و کارامد این آلاینده ها بیش از پیش مورد توجه قرار گرفته است تا با ابداع روش های نوین کارایی و تاثیر فرایند های حذف بهبود بخشیده شود. در این تحقیق استفاده از نانو ذرات روی اصلاح شده با شاخه های آلی در حذف زایلن از محیط های آبی مورد بررسی قرار گرفته است. روش کار: نانوذرات اکسید روی (Zno) توسط روش هم رسوبی شیمیایی تهیه گردید. به منظور افزایش راندمان جذب، در ابتدا اصلاح نانو ذرات صورت گرفت و در مرحله بعد مونومر عامل دار شده تهیه گردید و بر روی بدنه نانو ذرات اصلاح شده پیوند داده شد. عملکرد این جاذب در حذف زایلن به عنوان شاخص آلودگی نفتی مورد مطالعه قرار گرفت و اثر پارامتر های مختلف بر میزان جذب از قبیل pH محیط، زمان تماس و غلظت جاذب بررسی شد. یافته ها: نتایج بدست آمده نشان داد که بیشترین میزان جذب نانو جاذب سنتز شده در pH برابر با 6 و پس از گذشت 25 دقیقه از زمان تماس می باشد. همچنین نتایج نشان داد که با افزایش غلظت نانو جاذب درصد حذف نیز افزایش می یابد. بحث و نتیجه گیری: با توجه به بررسی های انجام شده کارایی بالای استفاده از نانواکسید روی اصلاح شده در حذف زایلن از محیط های آبی تایید گردید و امکان استفاده از آن در حذف آلاینده های نفتی از آب مطرح شد. پرونده مقاله -
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21 - اثرات نانوذرات اکسید روی بر بیان ژنهای انتقالدهنده روی 1-4 در سل لاین هیپوکامپ موشهای صحرایی نر
مائده نیله چی اکرم عیدی حمید گله داری مهناز کسمتیسابقه و هدف: عنصر روی نقش مهمی در کارکرد ارگانهای حیاتی، به ویژه سیستم عصبی مرکزی ایفا مینماید. اختلال در هموستازی روی موجب ایجاد و پیشرفت بیماریهای سیستم عصبی نظیر آلزایمر، افسردگی، اختلال در یادگیری و استرس میگردد. هموستازی روی در بدن توسط پروتئینهای ZnT و Z چکیده کاملسابقه و هدف: عنصر روی نقش مهمی در کارکرد ارگانهای حیاتی، به ویژه سیستم عصبی مرکزی ایفا مینماید. اختلال در هموستازی روی موجب ایجاد و پیشرفت بیماریهای سیستم عصبی نظیر آلزایمر، افسردگی، اختلال در یادگیری و استرس میگردد. هموستازی روی در بدن توسط پروتئینهای ZnT و ZIP صورت میپذیرد. هدف مطالعه حاضر بررسی اثر نانوذرات اکسید روی در بیان ژنهای انتقالدهنده روی 1-4 موسوم به Znt1،Znt2، Znt3 و Znt4در سلولهای هیپوکامپ به عنوان یکی از بافتهایی که تراکم بالایی از روی را در خود جای داده، میباشد. روش کار: ابتدا پاساژ سلولی رده سلولی هیپوکامپ انجام شد، سپس تست MTT assay برای نانوذره اکسید روی صورت گرفت. در مرحله بعد استخراج RNA و سنتز CDNA انجام شده و جهت اطمینان از خلوص نمونه RNA از اسپکتروفتومتر نانودراپ استفاده گردید و پرایمرهای اختصاصی و مناسب ژنهای مورد نظر طراحی و سنتز شد. سپس با استفاده از Real-Time PCR تغییرات بیان ژنهای Znt1، Znt2، Znt3 و Znt4 بررسی گردید. یافتهها: غلظتهای 10 و 20 μg/mL از نانوذره اکسید روی ضمن ایجاد کمترین سیتوتوکسیتی، موجب افزایش بیان معنادار هر چهار ژن Znt1،Znt2، Znt3 و Znt4 در رده سلولی هیپوکامپ موش صحرایی گردید. نتیجهگیری: نانوذره اکسید روی میتواند با افزایش بیان ژنهای انتقالدهنده روی Znt1،Znt2، Znt3 و Znt4 در درمان بیماریهای ناشی از اختلال هموستازی روی نظیر آلزایمر، افسردگی، اختلال در یادگیری و استرس مورد بررسی داروشناسی قرار گیرد. پرونده مقاله -
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22 - Sol-gel Synthesis and Characterization of Zinc Oxide Nanoparticles Using Black Tea Extract
Saeid Taghavi Fardood Ali Ramazani Sang Woo JooThe use of plant extract is generating the interest of researchers toward cost effective,nontoxic, economic viability and eco-friendly green synthesis of nanoparticles. In the presentwork, zinc oxide (ZnO) nanoparticles were synthesized using black tea extract and zinc چکیده کاملThe use of plant extract is generating the interest of researchers toward cost effective,nontoxic, economic viability and eco-friendly green synthesis of nanoparticles. In the presentwork, zinc oxide (ZnO) nanoparticles were synthesized using black tea extract and zinc nitrateas the zinc source by the sol-gel method. The synthesized ZnO nanoparticles werecharacterized by powder X-ray diffraction (XRD), UV-visible spectroscopy and FourierTransform Infrared Spectroscopy (FTIR). The average crystallite size of ZnO nanoparticleswas calculated using Scherrer formula. The X-ray powder diffraction (XRD) analysisrevealed the formation of wurtzite hexagonal phase ZnO with average particle size of 32 nm. پرونده مقاله -
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23 - Preparation and characterization of nano-ZnO catalyst and its application insynthesis of2-amino-3-phenylsulfonyl-4-aryl-4H-benzo[h]chromen derivatives
Vida Jodaian Bahareh SadeghiAn efficient and environmentally adapted synthesis of 2-amino-3-phenylsulfonyl-4-aryl-4H-benzo[h]chromenderivatives by condensation of a wide range of aryl aldehydes, α-naphthol and (phenylsulfonyl)acetonitrile using a catalytic amount of nano-ZnOunder solvent-fre چکیده کاملAn efficient and environmentally adapted synthesis of 2-amino-3-phenylsulfonyl-4-aryl-4H-benzo[h]chromenderivatives by condensation of a wide range of aryl aldehydes, α-naphthol and (phenylsulfonyl)acetonitrile using a catalytic amount of nano-ZnOunder solvent-free condition is explained. This catalyst was characterized by scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR),X-ray diffraction spectroscopy (EDX)and Thermogravimetric analysis (TG).As aresult, 2-amino-3-phenylsulfonyl-4-aryl-4H-benzo[h]chromens were produced under facile conditions in high yield (89-96%) and high rate (8-15 min) using nano-ZnO as a recyclable catalyst. پرونده مقاله -
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24 - Nanocatalyst of ZnO Supported Copper Oxide Catalyzed Chemoselective Synthesis of 1,1-diacetates
Jalal Albadi Azam MansournezhadIn this research, a metal oxide nanocatalyst of ZnO supported copper oxide is reported as a highly efficient recyclable catalyst for the chemoselective synthesis of 1,1-diacetates. The catalyst was synthesized by co-precipitation method and characterized by XRD, BET spe چکیده کاملIn this research, a metal oxide nanocatalyst of ZnO supported copper oxide is reported as a highly efficient recyclable catalyst for the chemoselective synthesis of 1,1-diacetates. The catalyst was synthesized by co-precipitation method and characterized by XRD, BET specific surface area, ESEM, EDS and TEM analysis. A wide range of aldehydes, including aromatic and aliphatic aldehydes were converted into the corresponding 1,1-diacetates. The experimental procedure with CuO-ZnO nanocatalyst is quite straightforward. The catalyst can be recovered by simple filtration and recycled up to 6 consecutive runs without any losing of its efficiency پرونده مقاله -
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25 - Preparation, Characterization and Photocatalytic Activity of Ag-Cd-ZnO and Ag-Cu-ZnO Nanostructures
Bahar Khodadadi Maryam Bordbar Maryam SajediIn this study, ZnO nanopowders and ZnO doped with metals (Cu , Ag- doped ZnO) and (Cd, Ag- doped ZnO) were synthesized by the sol-gel method in order to investigation on the codoping effect on the band gap and photocatalytic activity of ZnO. The synthesized samples are چکیده کاملIn this study, ZnO nanopowders and ZnO doped with metals (Cu , Ag- doped ZnO) and (Cd, Ag- doped ZnO) were synthesized by the sol-gel method in order to investigation on the codoping effect on the band gap and photocatalytic activity of ZnO. The synthesized samples are characterized by IR spectroscopy technique. Moreover, the absorption coefficients of the ZnO, Ag-Cd-ZnO and Ag-Cu-ZnO were analyzed by Tauc’s approach and the direct band gap is calculated. According to these results, compared with pure ZnO, the band gap of the Ag-Cd-ZnO and Ag-Cu-ZnO decreases and it is dependent on the content of dopands. Furthermore, photocatalytic activity for all samples was investigated under UV irradiation in an aqueous medium. The results have been revealed that Ag-Cd-ZnO and Ag-Cu-ZnO shown more photocatalytic actitivity in comparison with pure ZnO. پرونده مقاله -
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26 - Investigation of the absorption spectrum of annealed Zn nanorods in oxygen flux using discrete dipole approximation theory
Fatemeh AbdiIn this work, the discrete dipole approximations (DDA) theorywas used to investigate the absorption spectrum of annealed Zn nano rods in oxygen flux. For this purpose, the Zn nanorod was replaced with 1786 dipoles arranged on a rod-shaped structure, and the interaction چکیده کاملIn this work, the discrete dipole approximations (DDA) theorywas used to investigate the absorption spectrum of annealed Zn nano rods in oxygen flux. For this purpose, the Zn nanorod was replaced with 1786 dipoles arranged on a rod-shaped structure, and the interaction of these dipoles with polarized light was investigated. In this study, it was found that the extinction spectrum has two absorption peaks, which are related to the plasmonic oscillations, and Zn nanorods annealed in oxygen flux show metallic behavior. Changes in plasmonic oscillations were investigated by changing the deposition angle of nanorods and it was found that the oscillations in the direction perpendicular to the axis of the nanorod are strongly dependent on the angle of deposition and with increasing deposition angle, the number of oscillating dipoles and consequently the intensity of the absorption decreases sharply. پرونده مقاله -
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27 - Application of ZnO Nanorods for the Synthesis of Thiazole Derivatives via Multicomponent Reactions in Water
Ali Varasteh MoradiSimple three-component reactions between dialkyl acetylenedicarboxylate, primary amines and isothiocyanates in the presence of catalytic amount of ZnO nanorods are investigated in water at room temperature which produced thiazole derivatives in good yields.Simple three-component reactions between dialkyl acetylenedicarboxylate, primary amines and isothiocyanates in the presence of catalytic amount of ZnO nanorods are investigated in water at room temperature which produced thiazole derivatives in good yields. پرونده مقاله -
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28 - Application of Semiconductor Photocatalysis for Effective Elimination of Organic Contaminants from Sewage
Soodabe GharibeThe ZnO/SiO2 semiconductor nanophotocatalysis was synthesized via sol-gel method. Also, theplatinum particles were loaded on the ZnO/SiO2 nanoparticles by photoreductive method. Thestructure of catalyst was confirmed by X-ray diffraction (XRD), scanning electron microsc چکیده کاملThe ZnO/SiO2 semiconductor nanophotocatalysis was synthesized via sol-gel method. Also, theplatinum particles were loaded on the ZnO/SiO2 nanoparticles by photoreductive method. Thestructure of catalyst was confirmed by X-ray diffraction (XRD), scanning electron microscopy(SEM) andfourier transform infrared spectroscopy (FT-IR). The XRD patterns of ZnO particlesdisplayed the nanoparticles have a wurtzite structure (hexagonal phase). The crystallite sizes werecalculated using Scheerer’s equation and were around 32nm. For photocatalytic test, decompositionof Malachite Green oxalate (MG), as an organic pollutant was carried out by synthesized catalyst. Acomparison of degradation between bare catalyst and platinum loaded ZnO/SiO2nanoparticle underUV-Vis light irradiation shows that the Pt-ZnO/SiO2 photocatalyst is more efficient than ZnO/SiO2nanoparticles. Also, the activity of ZnO/SiO2nanoparticles in the visible light are minimal, whileloading of Pt in zinc oxide network displaced the band gap toward longer wavelengths (visiblelight) and increased the photocatalysis activity of ZnO/SiO2 in the range of visible light. پرونده مقاله -
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29 - A Comparative Photocatalytic Activity of ZnO/SiO2 and V2O5-ZnO/SiO2 by Investigating the Degradation of Rhodamine B
Soodabe Gharibe Leila Vafayi Shahrara AfsharZnO/SiO2was prepared using sol-gel method, and vanadium particles were loaded on this nano-photocatalyst by wet incipient method. They characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive (EDX) analysis andFouriertransform i چکیده کاملZnO/SiO2was prepared using sol-gel method, and vanadium particles were loaded on this nano-photocatalyst by wet incipient method. They characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive (EDX) analysis andFouriertransform infrared spectroscopy (FT-IR). The XRD patterns showed that the zinc oxide samples have a wurtzite structure and vanadium doped is in V2O5crystalline structure. The particle sizes werearound 32 nmcalculated using Scherrer’s equation. For photocatalytic test, decomposition of Rhodamine B(RB), as an organic pollutant, was carried out. The photocatalyst V2O5- ZnO/SiO2was found to be more efficient as compared with ZnO/SiO2. پرونده مقاله -
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30 - سنتز نانوالیاف کامپوزیتی SnO2/ZnO به روش الکتروریسی و بررسی عوامل موثر محلولی و فرآیندی بر مورفولوژی نانوالیاف حاصل
حامد اکبری خرمی منصور کیانپورراد محمدرضا واعظیدر این مقاله سنتز نانوالیاف کامپوزیتی SnO2/ZnO به روش ترکیبی الکتروریسی و فرآیند سل-ژل گزارش شده است. همچنین تاثیر ولتاژ کاری و غلظت پلی وینیل الکل بر مورفولوژی، اندازه و توزیع قطر نانوالیاف تهیه شده بررسی شده است. محلول های آماده شده از مواد پلی وینیل الکل، استات روی و چکیده کاملدر این مقاله سنتز نانوالیاف کامپوزیتی SnO2/ZnO به روش ترکیبی الکتروریسی و فرآیند سل-ژل گزارش شده است. همچنین تاثیر ولتاژ کاری و غلظت پلی وینیل الکل بر مورفولوژی، اندازه و توزیع قطر نانوالیاف تهیه شده بررسی شده است. محلول های آماده شده از مواد پلی وینیل الکل، استات روی و کلرید قلع با غلظت های متفاوت پلی وینیل الکل در آب، تحت فرآیند الکتروریسی قرار گرفتند تا الیاف کلریدقلع/استات روی/پلی وینیل الکل حاصل شود و پس از کلسینه شدن به مدت 6 ساعت در دمای °C650 نانوالیاف کامپوزیتی SnO2/ZnO تهیه شود. از آزمون های STA، XRD، SEM و EDX جهت مشخصه یابی و بررسی عوامل موثر بر مورفولوژی نانوالیاف استفاده گردید. نانوالیاف حاصل دارای قطر متوسط 75 نانومتر است. نتایج نشان داد که نانوالیاف کامپوزیتی SnO2/ZnO بدست آمده از خلوص فازی و شیمیایی بالایی برخوردار است. پرونده مقاله -
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31 - اثر افزودن اسپینل ZnFe2O4روی خواص فوتوکاتالیستی نانوذرات ZnO
پیمان فلک سید علی حسنزاده تبریزی علی صفار تلوریدر این پژوهش فعالیت فوتوکاتالیستی ZnO با باند گپ eV 2/3 و کامپوزیت آن با نیمههادی ZnFe2O4 با باند گپ eV 9/1 بررسی شده است. همچنین تاثیر افزایش درصد ZnFe2O4 به ZnO روی فعالیت فوتوکاتالیستی نانوکامپوزیت ZnO-ZnFe2O4 مورد بررسی قرار گرفته است. از روش میکروامولسیون معکوس به چکیده کاملدر این پژوهش فعالیت فوتوکاتالیستی ZnO با باند گپ eV 2/3 و کامپوزیت آن با نیمههادی ZnFe2O4 با باند گپ eV 9/1 بررسی شده است. همچنین تاثیر افزایش درصد ZnFe2O4 به ZnO روی فعالیت فوتوکاتالیستی نانوکامپوزیت ZnO-ZnFe2O4 مورد بررسی قرار گرفته است. از روش میکروامولسیون معکوس به عنوان روشی جدید در سنتز نانوذرات استفاده شده و همچنین مقادیر ZnO-(10, 30, 50%) ZnFe2O4 از این نانوکامپوزیت برای بررسی سنتز شده است. برای مشخصهیابی نانوذرات از آنالیزهای پراش پرتو ایکس (XRD)، میکروسکوپ الکترونی روبشی گسیل میدانی (FESEM)، طیفنگاری پراکندگی انرژی (EDS)، BETو طیفسنجی جذبی مرئی و فرابنفش (UV-Vis) استفاده شده است. نتایج نشان میدهد که روش میکروامولسیون با توانایی کنترل ابعاد ذرات، ذراتی نانومتری با سطح ویژه مناسب m2g-150 ایجاد کرده و ذراتی با اندازه 20-10 نانومتر ایجاد نموده که در افزایش فعالیت فوتوکاتالیستی نقش مهمی ایفا کرده است. این پژوهش نشان داد که بیشینه فعالیت فوتوکاتالیستی برای نانوکامپوزیت ZnO-50%ZnFe2O4 در 9pH= با مقدار تخریب 97% بدست آمده است. پرونده مقاله -
دسترسی آزاد مقاله
32 - سنتز دومرحلهای نانوساختار ZnO/Cu2O به روش هیدروترمال به منظور استفاده در پیلهای فتوالکتروشیمیایی
آروین اسکندری محمدرضا واعظی پروانه سنگپوردر این مقاله سنتز دومرحلهای نانوساختارهای ZnO/Cu2O به روش ترکیبی نمک مذاب و فرآیند هیدروترمال گزارش شده است. در ابتدا ساختارهای نانومقیاس اکسید روی به روش نمک مذاب تهیه شد. برای سنتز اکسید روی، واکنش کلرید روی و هیدروکسید سدیم-پتاسیم در بالاتر از دمای یوتکتیک آن (oC 20 چکیده کاملدر این مقاله سنتز دومرحلهای نانوساختارهای ZnO/Cu2O به روش ترکیبی نمک مذاب و فرآیند هیدروترمال گزارش شده است. در ابتدا ساختارهای نانومقیاس اکسید روی به روش نمک مذاب تهیه شد. برای سنتز اکسید روی، واکنش کلرید روی و هیدروکسید سدیم-پتاسیم در بالاتر از دمای یوتکتیک آن (oC 200) روی داد. بررسیهای فازی نشان میدهند که ماده تولید شده نیازی به عملیات حرارتی تکمیلی ندارد. با تغییر عوامل موثر بر واکنش، مورفولوژیهای متفاوتی از جمله صفحهای، گل شکل و سوزنی تشکیل شد. ساختار گل شکل بدلیل جذب نور بالا به عنوان هسته انتخاب شد. در مرحله دوم فرآیند، اکسید مس به روش هیدروترمال بر روی ساختار نانومقیاس ZnO سنتز گردید. از آزمونهای XRD، SEM و UV-Vis جهت مشخصهیابی و بررسی مورفولوژی نانوساختار و خواص نوری آن استفاده گردید. نتایج نشان داد که نانوساختار هسته-پوسته ZnO/Cu2O بدست آمده برای استفاده در پیلهای فتوالکتروشیمایی نسبت به نانوساختارهای اکسید روی، مناسبتر است. پرونده مقاله -
دسترسی آزاد مقاله
33 - سنتز، شناسایی و بررسی فعالیت فوتوکاتالیستی نانوکامپوزیت ZnO/SnO2 پوششدار شده با سالیسیلیک اسید
تکتم سیدی چوکانلو شکوفه آقابیگی نسیبه ملاحسنی فهیمه ابری ناییدر این تحقیق، ابتدا نانوکامپوزیت ZnO/SnO2 با روش سل-ژل تهیه و سپس با سالیسیلیک اسید پوشش داده شد (ZnO/Salicylicacid/SnO2). بررسی نتایج حاصل از تکنیکهای FESEM، XRD و TEM نشان داد که نانوذرات کروی شکل و دارای اندازه تقریبا nm 30 هستند. پوششدار شدن با سالیسیلیک اسید موجب چکیده کاملدر این تحقیق، ابتدا نانوکامپوزیت ZnO/SnO2 با روش سل-ژل تهیه و سپس با سالیسیلیک اسید پوشش داده شد (ZnO/Salicylicacid/SnO2). بررسی نتایج حاصل از تکنیکهای FESEM، XRD و TEM نشان داد که نانوذرات کروی شکل و دارای اندازه تقریبا nm 30 هستند. پوششدار شدن با سالیسیلیک اسید موجب کاهش باند گپ در نانوذرات ZnO/Salicylic acid/SnO2 نسبت به نانوکامپوزیت ZnO/SnO2 شده است. نتایج نشان دادکه نانوذرات ZnO/Salicylic acid/SnO2 و نانوکامپوزیت ZnO/SnO2 به ترتیب پس از min 30 تابشدهی قادر به تخریب90% و 70% از رنگدانه کنگورد CR تحت نور UV هستد. همچنین مطالعات سینتیکی نشان داد که جذب رنگ CR توسط نانوذرات ZnO/Salicylic acid/SnO2 و ZnO/SnO2، از یک معادله شبه مرتبه اول پیروی میکند و ثابت سرعت (k) برای تخریب توسط این ذرات به ترتیب 0191/0 و min−1 0091/0 محاسبه گردید. پوشش نانوکامپوزیت ZnO/SnO2 توسط سالیسیلیک اسید منجر به افزایش فعالیت فوتوکاتالیستی نانوذرات ZnO/Salicylic acid/SnO2 نسبت به ZnO/SnO2 بدون پوشش شده است. بنابراین، نانوذرات ZnO/Salicylic acid/SnO2 را میتوان به عنوان یک کاتالیزور مناسب برای حذف رنگدانه CR از محلول آبی مطرح کرد. پرونده مقاله -
دسترسی آزاد مقاله
34 - سنتز دو مرحلهای ساختارهای ناهمگون اکسید روی (ZnO) آلاییده شده با نانوذرات اکسید مس (CuO) برای حسگر گاز سولفید هیدروژن
احمد کمالیانفرنانوکامپوزیت اکسیدهای فلزی کاندیدای امیدوارکنندهای برای توسعه حسگرهای جدید گاز با عملکرد بالا در نظر گرفته میشوند. در کار حاضر، ساختار ناهمگون پیوند n-p اکسید روی و مس به روش ترکیب رسوب شیمیایی- فیزیکی بخار ساخته و پاسخ آن به گاز H2S در هوا مورد آزمایش قرار گرفت. ابتد چکیده کاملنانوکامپوزیت اکسیدهای فلزی کاندیدای امیدوارکنندهای برای توسعه حسگرهای جدید گاز با عملکرد بالا در نظر گرفته میشوند. در کار حاضر، ساختار ناهمگون پیوند n-p اکسید روی و مس به روش ترکیب رسوب شیمیایی- فیزیکی بخار ساخته و پاسخ آن به گاز H2S در هوا مورد آزمایش قرار گرفت. ابتدا، دو نانوساختار میلهای و کروی اکسید روی در داخل یک لوله cm 50 کوارتز و بر روی زیرلایه سیلیکون به روش رسوب شیمیایی رشد داده شد. به عنوان یک روش فیزیکی موثر در افزایش حساسیت حسگر، توسط دستگاه کندوپاش (sputtering)، سطح نانوساختارهای اکسید روی رشد داده شده با نانوذرات اکسید مس آلاییده شد. تصاویری که بوسیله SEM از سطح نمونهها گرفته شد، نشان میدهند که نانومیلههایی به طول چند میکرومتر و قطر کمتر از nm 80 و همچنین میکروکرههایی با قطر یک تا سه میکرومتر بر روی سطح زیرلایه سیلیکون رشد یافته بودند. نمونه ساخته شده با ساختار کروی شکل قادر به تشخیص گاز H2S با غلظت کم ppm 5 در دمای کار بهینه °C240 بود. همچنین در این دما بالاترین حساسیت (حدود 42) در حضور ppm 100 گاز H2S از خود نشان میدهد. زمان پاسخ و بازیابی برای تشخیص گاز سولفید هیدروژن، به ترتیب 8 و 18 ثانیه اندازهگیری شد که نسبت به نمونههای ساخته شده به روشهای دیگر، زمان بسیار مناسبی میباشد. نمودار تقریبا خطی حساسیت حسگر بر حسب غلظت گاز، از ویژگیهای خوب نمونه ساخته شده است که میتوان بر اساس آن حساسیت حسگر را برای غلظتهای مختلف تخمین زد. پرونده مقاله -
دسترسی آزاد مقاله
35 - Zno nanoparticles/silica for biginelli solution syntheis
Ali Javid Sabbaghian Parya Nasehi -
دسترسی آزاد مقاله
36 - Preparation and Characterization of ZrO2/ZnO Nanocomposite under Ultrasonic Irradiation via Sol-gel Route
Sh. Aghabeygi M. Zare-Dehnavi A. Farhadyar N. FarhadyarNanocomposite of ZrO2/ZnO was prepared under ultrasonic irradiation by sol gel process from directly mixing Zirconium and Zinc gels, and the mixture was placed under ultrasonic irradiation for 2 hours then aging time the filtrated composite gel was calcinated at 500° چکیده کاملNanocomposite of ZrO2/ZnO was prepared under ultrasonic irradiation by sol gel process from directly mixing Zirconium and Zinc gels, and the mixture was placed under ultrasonic irradiation for 2 hours then aging time the filtrated composite gel was calcinated at 500°C for 3h in furnace. The precursor sol of zirconium was prepared from an aqueous solution of ZrCl4 and zinc acetate dihydrated was dissolved in de-ionized water. The FT-IR analysis and the XRD study were exhibited that the crystal structure and purity of the ZrO2/ZnO nanocomposite FESEM images was indicated the morphology and the average size of the NPs. The average size of the ZrO2/ZnO nanocomposite was determined 37 nm. پرونده مقاله -
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37 - Catalytic Synthesis N-alkyl-3-acetyl-2-methylpyrroles using ZnO Nanostructure
A.S. Shahvelayati M. Sabbaghan S. BanihashemA simple, green synthesis of N-alkyl-3-acetyl-2-methylpyrrole derivatives using ZnO nanoparticles from the three component reaction of aliphatic amines, acetylacetone (as a 1,3-dicarbonyl compound) and α-haloketones under solvent-free condition is described.A simple, green synthesis of N-alkyl-3-acetyl-2-methylpyrrole derivatives using ZnO nanoparticles from the three component reaction of aliphatic amines, acetylacetone (as a 1,3-dicarbonyl compound) and α-haloketones under solvent-free condition is described. پرونده مقاله -
دسترسی آزاد مقاله
38 - Investigating Output Voltage and Mechanical Stability of a Piezoelectric Nanogenerator Based on ZnO Nanowire
S. Fathi T. Fanaei SheikholeslamiThe output of a piezoelectric nanogenerator based on ZnO nanowire is largely affected by the shape of nanowire. In order to obtain mechanically stable nanogenerator with high performance, the investigation of mechanical and electrical characteristics related to the nano چکیده کاملThe output of a piezoelectric nanogenerator based on ZnO nanowire is largely affected by the shape of nanowire. In order to obtain mechanically stable nanogenerator with high performance, the investigation of mechanical and electrical characteristics related to the nanowires and materials used in nanogenerators are of great interest and significance. This paper presents the various behavior of the conduction band, carrier concentration and the magnitude and distribution of the piezoelectric potential in cylindrical and conical shape ZnO nanowire (NW) by using finite element (FE) method. It is shown that symmetry reduction in nanowire shape and replacement the cylindrical NW with the conical NW, results in more advantageous both in terms of mechanical stability and piezoelectric potential. The large variation of the conduction band at the tip of conical nanowire results in receiving a large increase of maximum piezoelectric potential from -70 mv (cylindrical nanowire with radius of 30 nm) to -1750 mv (conical nanowire with tip radius of 5 nm and base radius of 30 nm). It is also shown that the insulating materials with lower Young’s modulus and lower relative permittivity are the best options in nanogenerator device fabrication. This numerical study can provide a guideline to design of the piezoelectric nanogenerator with high performance. پرونده مقاله -
دسترسی آزاد مقاله
39 - Novel functional finishing of wool fabric using reduced graphene oxide/zinc oxide nanocomposite
Loghman KarimiIn this study, a new finishing technique is introduced through treatment of wool fabric with reduced graphene oxide/ZnO nanocomposite. Graphene oxide was coated on to wool fabric by dipping the fabric in graphene oxide solution and drying in an oven. The nanocomposite w چکیده کاملIn this study, a new finishing technique is introduced through treatment of wool fabric with reduced graphene oxide/ZnO nanocomposite. Graphene oxide was coated on to wool fabric by dipping the fabric in graphene oxide solution and drying in an oven. The nanocomposite was synthesized on wool fabric in a single step by reduction of zinc acetate and graphene oxide with sodium hydroxide in the impregnation bath. The homogenous distribution of the reduced graphene oxide/zinc oxide nanocomposite on the fiber surface was confirmed by field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray spectroscopy (EDS) and X-ray mapping. X-ray diffraction patterns proved the presence of zinc oxide nanoparticles on the treated wool fabric. Also, the defect analysis based on X-ray photoelectron spectroscopy (XPS) established the composition of the nanocomposite. Other characteristics of treated fabrics such as antibacterial activity, photo-catalytic self-cleaning, electrical resistance, ultraviolet (UV) blocking activity and cytotoxicity were also assessed. The treated wool fabrics possess significant antibacterial activity and photo-catalytic self-cleaning property by degradation of methylene blue under sunlight irradiation. Moreover, this process has no negative effect on cytotoxicity of the treated fabric even reduces electrical resistance and improves UV blocking activity. پرونده مقاله -
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40 - بررسی اثر نرخ برش بر ویسکوزیته دینامیکی نانوسیال نانولوله کربنی چند جداره/ اکسید روی- روغن موتور در دماها و کسرهای حجمی مختلف
میثم اسدی سیف الله سعدالدیندر پژوهش حاضر به بررسی اثر نرخ برش بر ویسکوزیته دینامیکی نانوسیال ترکیبی نانولولهکربنی چندجداره/ اکسیدروی- روغن موتور پرداخته شده است. نانوسیال مورد مطالعه با استفاده از روش دومرحلهای و بدون استفاده از هیچگونه پایدار کننده در کسرهای حجمی مختلف (125/0، 5/0 و 1 درصد) بع چکیده کاملدر پژوهش حاضر به بررسی اثر نرخ برش بر ویسکوزیته دینامیکی نانوسیال ترکیبی نانولولهکربنی چندجداره/ اکسیدروی- روغن موتور پرداخته شده است. نانوسیال مورد مطالعه با استفاده از روش دومرحلهای و بدون استفاده از هیچگونه پایدار کننده در کسرهای حجمی مختلف (125/0، 5/0 و 1 درصد) بعنوان نمونه آزمایشگاهی تولید شد. کلیه آزمایشات در محدوده دمایی بین 5 تا 55 درجه سانتیگراد و در نرخهای برش بین 50 تا 1000 دور بر دقیقه انجام شده است. نتایج آزمایشات انجام شده برروی نانوسیال مورد مطالعه نشان میدهد که گرچه سیال پایه در تمامی دماها و نرخهای برش مورد مطالعه رفتاری نیوتنی از خود نشان میدهد، نانوسیال تولید شده در دماهای 5 و 15 درجه سانتیگراد، رفتاری غیرنیوتنی و در دماهای 25، 35، 45 و 55 درجه سانتیگراد، رفتار نیوتنی از خود نشان میدهد. پرونده مقاله -
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41 - بررسی اثر اسانس آویشن و نانو ذره اکسید روی بر اسینتوباکتر بومانی دارای مقاومت چند دارویی
فاطمه نوربخش مژگان علیکاهی معصومه مهدویچکیده مقدمه: در حال حاضر بسیاری از داروهای ارزشمند اثر خود را بر اسینتوباکتر بومانی از دست داده اند و مقاومت دارویی اسینتوباکتربومانی علت اصلی شکست درمان عفونتهای بیمارستانی ناشی ازآن میباشد. هدف از این تحقیق بررسی اثر اسانس آویشن و نانو ذره اکسید روی بر اسینتوباکتر بوم چکیده کاملچکیده مقدمه: در حال حاضر بسیاری از داروهای ارزشمند اثر خود را بر اسینتوباکتر بومانی از دست داده اند و مقاومت دارویی اسینتوباکتربومانی علت اصلی شکست درمان عفونتهای بیمارستانی ناشی ازآن میباشد. هدف از این تحقیق بررسی اثر اسانس آویشن و نانو ذره اکسید روی بر اسینتوباکتر بومانی دارای مقاومت چند دارویی میباشد. مواد و روش ها: این مطالعه بر روی46 سویه اسینتوباکتر بومانی جدا شده از نمونه های بالینی بیماران بیمارستان قلب تهران انجام گرفت. حساسیت آنتی بیوتیکی باکتری های جداشده با روش انتشار از دیسک بر اساس استاندارد2018 CLSI تعیین شد. آزمون میکرودایلوشن براث برای تعیین حداقل غلظت بازدارندگی (MIC) برای آنتی بیوتیک های آمیکاسین، سیپروفلوکساسین، ایمیپنم، اسانس آویشن و نانو ذره اکسید روی انجام شد. یافته ها: براساس نتایج به دست آمده از تست های تعیین حساسیت به روش دیسک دیفیوژن مشخص شد که بیشترین میزان مقاومت سویه ها به آنتی بیوتیک های ایمیپنم و سیپروفلوکساسین به میزان 82/97% بوده است. در مطالعه حاضر بیشترین حساسیت سویه ها به اسانس آویشن در غلظت µg/ml 5/0 و کمترین حساسیت متعلق به غلظت های 312/0 و 625/0 µg/ml مشاهده شد، همچنین بر اساس نتایج به دست آمده در این مطالعه بیشترین حساسیت سویه ها به نانو ذره در غلظت µg/ml 4096و کمترین حساسیت در غلظت µg/ml 256 بوده است. بحث و نتیجه گیری: نتایج این پژوهش بیانگر اثر مهار کنندگی قوی اسانس آویشن و نانو ذره اکسید روی براسینتوباکتربومانی دارای مقاومت چند دارویی می باشد . پرونده مقاله -
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42 - اثرات ضدمیکروبی نانوذرات اکسیدروی بر پایه سیلیکاژل تهیه شده با روش نمک مذاب
محمد قربان پورهدف از تحقیق حاضر ارائه روشی جدید جهت تهیه نانوکامپوزیت اکسیدروی/سیلیکاژل میباشد. بدین منظور، از غوطهور کردن سیلیکاژل در نمک مذاب سولفاتروی در دمای 560 درجه سلسیوس استفاده شد. برای سنتز این نانوکامپوزیت از هیچ عامل احیا کننده و یا ماده شیمیایی بهغیر از سولفات روی ا چکیده کاملهدف از تحقیق حاضر ارائه روشی جدید جهت تهیه نانوکامپوزیت اکسیدروی/سیلیکاژل میباشد. بدین منظور، از غوطهور کردن سیلیکاژل در نمک مذاب سولفاتروی در دمای 560 درجه سلسیوس استفاده شد. برای سنتز این نانوکامپوزیت از هیچ عامل احیا کننده و یا ماده شیمیایی بهغیر از سولفات روی استفاده نشد و با این روش سنتز نانوذرات و تثبیت آنها بر روی پایه در زمانی کمتر از 60 دقیقه میسر شد. نانوکامپوزیت اکسیدروی/سیلیکاژل ساخته شده توسط میکروسکوپ الکترونی روبشی و اسپکترومتر فرابنفش-مرئی مورد ارزیابی قرار گرفت. بر اساس نتایج میکروسکوپ الکترونی روبشی مشخص شد که تماس سیلیکاژل با نمک مذاب منجر به تشکیل نانوذرات بر روی سطح سیلیکاژل شده است. از سوی دیگر، افزایش زمان تماس موجب بزرگتر شدن نانوذرات اکسید روی شد. نتایج حاصل از کشت میکروبی نشان دادند که با تماس 60 دقیقهای مابین سیلیکاژل و نمک مذاب نانوکامپوزیت بهینه با کشندگی بالای 85/99 درصد علیه باکتری اشریشیا کولای حاصل شد. تست آبشویی نیز بر پایداری نانوکامپوزیتهای ساخته شده دلالت داشت و میزان رهاسازی روی در آب کمتر از 5/1 درصد بود. پرونده مقاله -
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43 - Amelioration of the acid blue oxidation process by as-synthesized ZnO nanoparticles: Optimization of the dye and photocatalyst concentration together with the pH of the solution
Mehrnaz Gharagozloua Sanaz Naghibi Mohammad Ebrahim OlyaIn this research, ZnO nanoparticles (NPs) were synthesized using a binary Zn(II) Schiff-base complex. The complex heat-treated to prepare ZnO nanoparticles via thermal decomposition route at a temperature of 500 °C. The formation of single-phase ZnO nanoparticles an چکیده کاملIn this research, ZnO nanoparticles (NPs) were synthesized using a binary Zn(II) Schiff-base complex. The complex heat-treated to prepare ZnO nanoparticles via thermal decomposition route at a temperature of 500 °C. The formation of single-phase ZnO nanoparticles and their microstructures were studied by XRD pattern, SEM and TEM observation. The photo-degradation characteristic of the as-prepared ZnO NPs was evaluated and acid blue 193 was investigated as the organic colorant in a photocatalytic reactor by advanced oxidation process (AOP). The effects of operating parameters such as initial concentration of the dye, amount of catalyst and the pH value of the solutions were studied to determine the optimum condition of the process to improve the photo-degradation performance. According to the results, impressive photo-degradation of acid blue is conceivable by the as-synthesized ZnO NPs. The optimum operating conditions to achieve photo-degradation were found to be a solution with pH value of 6, the catalyst concentration of 0.04 g/L, and the dye concentration of 10 g/L. The highest efficiency would be achieved at natural pH of the solution (pH=~6). The optimum concentration of ZnO NPs is about 0.04 g/L. More or less amount of the photocatalyst could not enhance the photodegradation efficiency. At the constant photocatalyst concentration, any increase in dye amounts leads to decrease in degradation efficiency. پرونده مقاله -
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44 - Structural, Optical and Ultra-Violet Photodetection Properties of ZnO Nanorods with Various Aspect Ratios
Saeed Safa Elham Hasani Majid ZarehZnO nanorods with various lengths were synthesized by a two-stage route (by changing the time of growth between 0-240 min) and were characterized using XRD, SEM, UV–Vis and PL techniques. The SEM and XRD results confirmed a fast growth of (0 0 2) plane in the pref چکیده کاملZnO nanorods with various lengths were synthesized by a two-stage route (by changing the time of growth between 0-240 min) and were characterized using XRD, SEM, UV–Vis and PL techniques. The SEM and XRD results confirmed a fast growth of (0 0 2) plane in the preferential longitudinal orientation, in contrast to lateral growth and therefore, by increasing the time of hydrothermal growth, nanorods with higher aspect ratios are obtained. Naturally, by increasing the length of nanorods, not only the average transmittance in both near ultraviolet and visible ranges is decreased, but also the PL peaks are red-shifted and extinct. Finally, ultra-violet photodetection of the samples shows that higher active surface area (with respect to the time of growth) is appropriate for photo-induced interactions leading to higher UV-sensitivity. پرونده مقاله -
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45 - Influence of Cr dopant on the microstructure and optical properties of ZnO nanorods
Saeed Safa A. Masoudi NejadOne-dimensional (1D) undoped and Cr doped ZnO nanorods with average length of 1 µm and diameter of 80 nm were synthesized using hydrothermal method where a fast growth of ZnO nanorods on the seed layer was observed. Afterwards, the effects of Cr dopant on structur چکیده کاملOne-dimensional (1D) undoped and Cr doped ZnO nanorods with average length of 1 µm and diameter of 80 nm were synthesized using hydrothermal method where a fast growth of ZnO nanorods on the seed layer was observed. Afterwards, the effects of Cr dopant on structural, surface morphology and optical properties of nanorods were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultra-violet visible (UV-Vis) spectroscopy. The results showed that ZnO has a wurtzite hexagonal structure and that the Cr atoms were well incorporated into the ZnO crystal structure. Moreover, it was found that the Cr atoms could facilitate the preferential growth of nanorods in C-axis. Also, it was concluded from optical properties that doped ZnO nanorods was so appropriate for photocatalytic applications because the optical band gap. For example, the calculated band gap of ZnO nanorod decreased from 3.12 eV for pure ZnO nanorods to about 2.41eV for 3 at. % Cr doped ZnO nanorods which is quite enough to be activated even at visible (550nm) light for photocatalyst aims. پرونده مقاله -
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46 - Investigation of corrosion behavior of galvanized mild steel by improved Zn acidic bath, containing nano-ZnO particles
Behrooz ShayeghIn this study, nano-ZnO particles were deposited on mild steel sheets from an acidic zinc bath. These particles were synthesized by using an auto combustion technique. The effect of concentration of nano- ZnO particles on the corrosion behavior of depositions was invest چکیده کاملIn this study, nano-ZnO particles were deposited on mild steel sheets from an acidic zinc bath. These particles were synthesized by using an auto combustion technique. The effect of concentration of nano- ZnO particles on the corrosion behavior of depositions was investigated. The results of salt spray tests and electrochemical measurements showed that corrosion resistance is improved by addition of nano-ZnO particles into acidic zinc bath. Based on results, coating contain 0.5g of zinc oxide nano-particles had lowest corrosion rate (1.022mpy) and high corrosion resistance. Scanning electron microscopy (SEM) and X- ray diffraction (XRD) were used for studying the surface morphology and crystal structure of the zinc deposit. SEM observations showed that zinc-oxide nano-particles by absorption of the corrosive agents had action as a barrier against corrosive environment. The study of XRD pattern showed that the adding of nano ZnO was decreased the amount of corrosion products which indicated a higher corrosion resistance than the sample without any nano-particles. پرونده مقاله -
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47 - Investigating structural, optical and photocatalytic properties of hydrothermally synthesized ZnO nanorod arrays with various aspect ratios
Saeed Safa Ali Khayatian eliza rokhsat Mehrdad NajafiZnO nanorods with various aspect ratios (by changing the time of growth between 0-240 min) were synthesized using hydrothermal method and were investigated using XRD, SEM, UV–Vis and PL. It was found that growth time is directly coupled with the length, orientatio چکیده کاملZnO nanorods with various aspect ratios (by changing the time of growth between 0-240 min) were synthesized using hydrothermal method and were investigated using XRD, SEM, UV–Vis and PL. It was found that growth time is directly coupled with the length, orientation and aspect ratio of the nanorod arrays. The optical transmittance of the NR arrays indicated a regular decrement of average transmittance with increasing the aspect ratio of NRs in the visible range. The optical constants (absorption coefficient, extinction coefficient and refractive index) can be account as a function of refractive index were determined. The porous ZnO nanorod with the thickness of ∼ 1560 nm and texture coefficient of 0.96 for (002) plane exhibits the average visible transmittance <60%, refractive index 1.34, packing density 0.26 and lowest optical band gap, was fabricated in the longest time of hydrothermal growth (240 min). As the growth time was increased, the photoluminescence properties was sustained a general weakening tendency and a red-shift of UV-emission peak position. The UV-assisted photocatalytic degradation of 4-Nitrophenol (4-NP) of ZnO NRs were investigated. The considerable photocatalytic performance of ZnO NRs with highest aspect ratio was explained by its porosity and optical characteristics. پرونده مقاله -
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48 - بررسی اثر نانوذره اکسیدروی بر رشد، رنگیزههای فتوسنتزی و اسمولیتهای محلول گیاه نوروزک (Salvia leiifolia Benth.) تحت شرایط تنش شوری
مهدی آخوندی مریم نیاکان هما محمودزاده مجید دشتیتنش شوری یکی از اصلیترین عوامل محدودکننده رشد و تولید گیاهان میباشد. عنصر روی ازجمله عناصر ضروری در رشد و فرایندهای متابولیسمی میباشد که مصرف آن سبب مقاومت گیاهان به تنشهای محیطی میشود. از سوی دیگر کاربرد عناصر در شکل نانو بهعلت سهولت جذب عناصر امروزه مورد توجه قر چکیده کاملتنش شوری یکی از اصلیترین عوامل محدودکننده رشد و تولید گیاهان میباشد. عنصر روی ازجمله عناصر ضروری در رشد و فرایندهای متابولیسمی میباشد که مصرف آن سبب مقاومت گیاهان به تنشهای محیطی میشود. از سوی دیگر کاربرد عناصر در شکل نانو بهعلت سهولت جذب عناصر امروزه مورد توجه قرارگرفته است. بهمنظور بررسی اثر محلولپاشی نانواکسیدروی در شرایط تنش شوری، آزمایشی در قالب طرح فاکتوریل بر پایه طرح کاملاً تصادفی در سه تکرار اجرا شد. عوامل آزمایشی شامل دو سطح نانواکسیدروی (2 و 4 میلیگرم بر لیتر) و 5 سطح شوری (صفر، 50، 100، 150 و 200 میلیمولار) نمک کلرید سدیم در کنار شاهد بود. نتایج حاصل از این تحقیق نشان داد که طول ساقه، وزنتر گیاه، تعداد برگ، سطح برگ و میزان رنگیزههای فتوسنتزی و همچنین میزان کربوهیدراتهای محلول در سطو مختلف شوری کاهش معنیداری یافت. از سوی دیگر تیمار 4 میلیگرم در لیتر نانواکسیدروی با تأثیر مثبتی بر پارامترهایی رشد، شاخص پایداری کلروفیل، میزان کلروفیل و کاروتنوئیدها، پرولین و قندهای محلول برگ و ریشه داشت. همچنین بررسی اثر متقابل دادهها نشان داد که بیشترین میزان طول ریشه و وزنتر کل در سطح 50 میلیمولار کلرید سدیم و نیز میزان پرولین وکلروفیل مربوط به سطح 100 میلیمولار کلرید سدیم همراه با محلولپاشی نانواکسیدروی با غلظت 4 میلیگرم در لیتر بود. بهطورکلی در این تحقیق مشخص شد مصرف نانواکسیدروی با غلظت 4 میلیگرم در لیتر توانست سبب بهبود رشد گیاه و اسمولیتهای سازگار و در نتیجه بهبود پاسخ گیاه نوروزک به تنش شوری گردد. پرونده مقاله -
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49 - اتنوبوتانی و بررسی ترکیبات شیمیایی اسانس اندامهای مختلف گیاه دارویی Tanacetum parthenium L. در منطقه کوهستانی درازنو واقع در جنوب غرب استان گلستان
م مازندرانی غ.م ناصری م،ب رضایی س.م کسائییافتههای این تحقیق نشان داد که گیاه دارویی داوودی وحشی T. parthenium L. یکی از گونههای ارزشمند و بومی استان گلستان است که در طب سنتی مردم بومی منطقه از آن در درمان سردرد، سرماخوردگی، تب، ضدعفونی و مسکن دردهای ورم مفاصل، رماتیسم و دیسموزه استفاده میشود. لذا در مردادما چکیده کاملیافتههای این تحقیق نشان داد که گیاه دارویی داوودی وحشی T. parthenium L. یکی از گونههای ارزشمند و بومی استان گلستان است که در طب سنتی مردم بومی منطقه از آن در درمان سردرد، سرماخوردگی، تب، ضدعفونی و مسکن دردهای ورم مفاصل، رماتیسم و دیسموزه استفاده میشود. لذا در مردادماه 1385، گلها و برگهای گیاه از رویشگاه طبیعی خود واقع در 2200 متری کوهستان درازنو در جنوب غرب استان گلستان جمعآوری شدند و به روش تقطیر با آب اسانسگیری و آنالیز مواد موثره اسانس اندامهای مختلف گیاه توسط دستگاه GC/MS انجام گرفت. نتایج نشان داد که مهمترین مواد موثره اسانس گلها شامل: کامفور، آلفا ـ پینن و آلفا ـ بیزابولول اکسید B ولی در اسانس برگها شامل کامفور، آلفا ـ پینن، و پیپریتون بودند. پرونده مقاله -
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50 - بررسی اثر نانواکسیدروی بر عملکرد، میزان کیفیت و کمیت ترکیبات اسانس گیاه دارویی Salvia leriifolia Benth. در شرایط تنش شوری
مهدی آخوندی مجید دشتی مریم نیاکان هما محمود زاده آخرتدر گیاهان دارویی تولید متابولیتهای ثانویه بهویژه اسانس تحت تأثیر عوامل محیطی مختلفی از جمله شوری قرار میگیرند. در این تحقیق به منظور بررسی اثر سطوح مختلف تنش شوری و نانواکسیدروی بر عملکرد کمی و کیفی ترکیبات اسانس گیاه نوروزک (Salvia leriifolia Benth.)، یک آزمایش فاکت چکیده کاملدر گیاهان دارویی تولید متابولیتهای ثانویه بهویژه اسانس تحت تأثیر عوامل محیطی مختلفی از جمله شوری قرار میگیرند. در این تحقیق به منظور بررسی اثر سطوح مختلف تنش شوری و نانواکسیدروی بر عملکرد کمی و کیفی ترکیبات اسانس گیاه نوروزک (Salvia leriifolia Benth.)، یک آزمایش فاکتوریل با پنج سطح شوری (0، 50، 100، 150 و 200 میلیمولار کلریدسدیم) و سه سطح نانواکسید روی ( 0 ، 2 و 4 میلیگرم در لیتر) درقالب طرح کاملاً تصادفی در سه تکرار در گلخانه دانشگاه آزاد اسلامی مشهد در سال ۱۳۹۸ انجام گردید. اسانسگیری به روش تقطیر با آب توسط دستگاه کلونجر از اندام هوایی رویشی گیاه انجام شد. تجزیه اسانس با استفاده از دستگاه کروماتوگراف گازی و کروماتوگرافی متصل به طیف سنج جرمی انجام شد. نتایج نشان داد، تأثیر سطوح مختلف تنش شوری بر وزن خشک، بازدهی و عملکرد اسانس گیاه نوروزک معنیدار بود، لیکن کاربرد نانو اکسید روی، تنها بازدهی و عملکرد اسانس را تحت تأثیر قرار داد. با افزایش تنش شوری، وزن خشک برگ‎ها، درصـد و عملکرد اسانس برگ بهطور قابل ملاحظهای کاهش یافت، در حالی که افزایش غلظت نانو اکسیدروی باعث افزایش صفات فوق در سطوح بالای شوری گردید. ماده موثره 1و8- سینئول بیشترین ترکیب اسانس گیاه را تشکیل داد که با افزایش سطح شوری مقدار آن 43 درصد افزایش نشـان داد. ترکیبات ایزوپینوکاروئل، کاروتول، اندوبرونئول نیز در سطوح پایین شوری ابتدا کاهش و سپس در سطح 200 میلیمـولار شـوری افزایش یافت. همچنین افزایش غلظت نانوذرات اکسیدروی سبب افزایش میزان اندوبرونوئل، 1و 8- سینئول و بتا- پینن و کاهش میزان ایزوپینوکاروئل، کاروتول و آلفا- کادینول شد. پرونده مقاله -
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51 - Effect of growth time on ZnO thin films prepared by low-temperature chemical bath deposition on PS substrate
Reza Shabannia Nima NaderiZnO thin films were successfully synthesized on a porous silicon (PS) substrate by chemical bath deposition method. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and photoluminescence (PL) analyses were carried out to investigate the eff چکیده کاملZnO thin films were successfully synthesized on a porous silicon (PS) substrate by chemical bath deposition method. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and photoluminescence (PL) analyses were carried out to investigate the effect of growth duration (3, 4, 5, and 6 h) on the optical and structural properties of the aligned ZnO nanorods. The small FWHM and stronger diffraction intensity of growth times of 5 h mean the better crystal quality of ZnO thin films compared to others. The grain size of the ZnO thin films gradually increased with increased the growth time. The FESEM images show that the thickness of ZnO thin films increased with increase of the growth time. Photoluminescence measurements showed that there was a sharp and highly intense UV emission peak when growth time was 5 h. The structural and optical investigations revealed that the ZnO thin films grown on the PS substrate with growth time of 5 h had high structural and optical quality. پرونده مقاله -
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52 - Preparation of antibacterial coating film using ZnO nanoparticles and epoxy resin
hamid reza ghorbani shakiba amirsoleimaniThe production of antibacterial and antifungal nanocomposites is widely used in pharmaceutical, health, food, packaging and medicine industries. Meanwhile, epoxy coating film is one of the most commonly used protective coatings in industrial applications. In this work, چکیده کاملThe production of antibacterial and antifungal nanocomposites is widely used in pharmaceutical, health, food, packaging and medicine industries. Meanwhile, epoxy coating film is one of the most commonly used protective coatings in industrial applications. In this work, ZnO nanoparticles were first synthesized at three different concentrations. UV-Vis spectroscopy and dynamic light scattering (DLS) analysis were used to study the nanoparticles properties. The results showed that nanoparticles were synthesized with a mean size of 46 nm at 0.01 M zinc sulfate. Then, the nanoparticles were mixed with epoxy at three concentrations and finally ZnO/epoxy nanocomposite were prepared. X-ray diffraction (XRD) and Scanning electron microscopy (SEM) confirmed the existence and size of nanoparticles in epoxy film. The disk diffusion method was used to study the antibacterial activity of ZnO-epoxy nanocomposites against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The results exhibited that the optimum antibacterial activity was in nanocomposite films with concentration 0.01 M of zinc sulfate. پرونده مقاله -
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53 - The removal of Hexavalent chromium; (Cr (VI)) by ZnO/LECA as a nano photocatalyst using full factorial experimental design
Aref Shokri Safoora KarimiIn this research, a synthesized nano photocatalyst was prepared by supporting ZnO nanoparticle on Lightweight expanded clay aggregate (LECA). The catalyst was synthesized by co-precipitation method. The SEM, FT-IR and XRD tests were used to characterize ZnO/LECA, which چکیده کاملIn this research, a synthesized nano photocatalyst was prepared by supporting ZnO nanoparticle on Lightweight expanded clay aggregate (LECA). The catalyst was synthesized by co-precipitation method. The SEM, FT-IR and XRD tests were used to characterize ZnO/LECA, which was employed for photocatalytic removal of Cr (VI) from aqueous solution in batch photoreactor. The full factorial experimental design (FFD) was used for the statistical analysis of data. The influence of catalyst amounts, pH, and initial concentration of Cr (VI) was investigated on the reduction of Cr (VI) to Cr (III). The number of active site was increased with increase in the concentration of catalyst to some extent. Also, the selection of other factors in optimized amount was important. The optimal conditions were obtained at 0.75 g/l of photocatalyst, pH at 5 and 20 mg/l of Cr(VI). The experimental and predicted reduction efficiency by FFD at optimal conditions were 97.6 and 96.18%, respectively. The comparison of experimental and predicted data showed a good agreement between them. پرونده مقاله -
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54 - Photocatalytic degradation of Malachite Green using ZnO and ZnO-TiO2 nanoparticles from aqueous solution
hadi baseri Elahe AlizadehToday, despite of the increasing demands for the products of chemical industries and the related factories, the challenges of environmental pollution has not been improved and it is approaching a very dangerous stage. In this regard, the role of dyeing industries in con چکیده کاملToday, despite of the increasing demands for the products of chemical industries and the related factories, the challenges of environmental pollution has not been improved and it is approaching a very dangerous stage. In this regard, the role of dyeing industries in contaminating the environment is undeniable. In this research, ZnO and ZnO-TiO2 nanoparticles were synthesized by co-precipitation and sol-gel methods, respectively. The synthesized nanoparticles were characterized by XRD and FE-SEM techniques and their band gap energy were determined using the UV-Vis spectrum obtained from the suspension of nanoparticles. By using synthesized nanoparticles, degradation of malachite green under irradiation of the UV (A)-Visible mixture light from aqueous solution were evaluated and the effect of different parameters such as amount of photo catalyst, time of light irradiation and dose of H2O2 have been studied. The destruction amount was determined by UV-Vis spectroscopy method. Based on the reported results, the maximum degradation efficiency of about 99% was obtained in the optimal values of experimental conditions. پرونده مقاله -
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55 - ZnO/WO3 nanocomposites: Pechini sol-gel synthesis, characterization, and photocatalytic performance for desulfurization of thiophene
Mehdi Mousavi-Kamazani Nahid Kalhori Mohammad GhodratiIn recent decades, considerable research about the destruction of hazardous pollutants sulfur from petroleum products was conducted. However, reforms in this area have not been satisfactory and efforts are ongoing. The aim of this study was to investigate and overcome t چکیده کاملIn recent decades, considerable research about the destruction of hazardous pollutants sulfur from petroleum products was conducted. However, reforms in this area have not been satisfactory and efforts are ongoing. The aim of this study was to investigate and overcome thiophene sulfur contaminants using high purity synthesized ZnO/WO3 nanocomposite and homogeneous composition by Pechini sol-gel method at low temperature. Zinc oxide is one of the most dynamic elements known in this field, its presence together with tungsten oxide prevents the crystallization of tungsten nanoparticles. Fuzzy structure, percentage of elements, surface morphology, penetration reflection spectrum, and photocatalytic degradation of thiophene were determined by XRD, EDS, SEM, and DRS analyzes, respectively. DRS results indicate high light absorption, reduced bandgap due to the presence of WO3 after combination with ZnO, and increased efficiency. Finally, the nanocomposite with more than 84% efficiency resulted in the degradation of oxidative desulfurization of thiophene after 150 min under visible light. پرونده مقاله -
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56 - Synthesis, characterization and photocatalytic activity of nanoZnO and Ni-Co-ZnO nanocomposites
Sara Poorarjmand Maryam Kargar Razi Ali Reza Mahjoub Morteza KhosraviPhotocatalysis has attracted significant attention as a potential issue for degradation of toxic organic pollutants such as Congo Red. In this research spherical Pure ZnO nano particles and Ni-Co-ZnO nano composites (Zn0.95Ni0.04Co0.01O, Zn0.95Ni0.025Co0.025O and Zn0. چکیده کاملPhotocatalysis has attracted significant attention as a potential issue for degradation of toxic organic pollutants such as Congo Red. In this research spherical Pure ZnO nano particles and Ni-Co-ZnO nano composites (Zn0.95Ni0.04Co0.01O, Zn0.95Ni0.025Co0.025O and Zn0.95Ni0.01Co0.04O) have been synthesized by precipitation method. X- ray diffraction, Fourier transform Infra Red ,field emission scanning electron microscopy, EDX and ICP analysis confirmed the structure and composition of samples. The x-ray diffraction analysis (XRD) showed that all samples prepared were of Wurtzite structure and average crystal size of 17nm. Field emission scanning electron microscopy (FESEM) analysis revealed the spherical shape of all samples. The Fourier transform infrared spectroscopy (FT-IR) revealed bands at 435 cm-1, 480 cm-1 and 525 cm-1 are related to Zn-O bonds , related to the stretching vibrating bonds of ZnO. The results illustrated the Ni and Co ions substituted the Zn ions in ZnO crystal lattice successfully. The results showed that some of doped Ni-Co ZnO exhibit enhanced photocatalytic activity , as compared to pure ZnO. Kinetic of de-colorization process for all photo-catalysts followed psedu first order. In degradation process The best photocatlyst was (Zn0.95Ni0.04Co0.01O). پرونده مقاله -
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57 - Synthesis of ZnO/Graphene Oxide Nanocomposites and its Application in the Photo-removal of Methylene Blue Dye from Aqueous Solution under Ultra Violet Light
Kasra Behzad Monir Niazi Afarin BahramiIt has been found that semiconductor nanocomposites have good photocatalytic behavior and can be used for the photodegradation of organic pollutants in water waste. ZnO, one of the eco-friendly semiconductor materials, was chosen to form a nanocomposite with graphene ox چکیده کاملIt has been found that semiconductor nanocomposites have good photocatalytic behavior and can be used for the photodegradation of organic pollutants in water waste. ZnO, one of the eco-friendly semiconductor materials, was chosen to form a nanocomposite with graphene oxide. Graphene oxide in ZnO-based nanocomposites improves the photoactivity and photostability of ZnO. To prepare the graphene oxide, the Hummers method was used, then ZnO/GO nanocomposite was synthesized by hydrothermal method. The nanocomposites were annealed at different temperatures of 300 °C, 400 °C, and 500 °C. Raman spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR) confirmed the structure of synthesized graphene oxide nanosheets. Structural characterization of the nanocomposites was investigated using X-ray diffraction, Transmission Electron Microscope (TEM), and Field Emission Scanning Electron Microscope (FE-SEM). X-ray diffraction patterns of nanocomposites demonstrate that the annealed sample at 300 °C has better crystallinity than the other samples and was used to investigate the photocatalytic process. Photocatalytic experiment of the ZnO/GO was carried out by degradation of methylene blue using a laboratory-made reactor in alkaline, acidic, and neutral solutions. Photodegradation results were revealed that the maximum percent degradation of 87% was achieved in the alkaline solution. پرونده مقاله -
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58 - Facile Synthesis and Investigation of Flower like p-NiO/n-ZnO as Efficient Photocatalyst for Degradation of Erythromycin under Sunlight
Sajad Khamani Mohammad Hossein Ghorbani Leila Torkian Reza Fazaeli Zahra KhodadadiConventional wastewater treatment is not able to effectively removal drugs such as antibiotics, so it is important to remove the remaining antibiotics from the environment. In this research, Zinc oxide (ZnO), nickel oxide (NiO) and p-NiO/n-ZnO heterostructure were synth چکیده کاملConventional wastewater treatment is not able to effectively removal drugs such as antibiotics, so it is important to remove the remaining antibiotics from the environment. In this research, Zinc oxide (ZnO), nickel oxide (NiO) and p-NiO/n-ZnO heterostructure were synthesized. Then, prepared samples were characterized by several techniques. The photocatalytic degradation of erythromycin from aqueous solutions was studied by photocatalysts synthesized under sunlight. Design of Experimental (DOE) was used to evaluate the effective parameters in the degradation process of erythromycin. The effects of pH, time (min), photocatalytic mass (g) and erythromycin concentration (mg/L) were studied. Using Design Expert 7 software, the highest degradation efficiency of erythromycin was found 99.54%, under optimum conditions at pH 3.07, time 101.14 (min), photocatalyst mass 0.13 (g) and erythromycin concentration 41.04 (mg/L). Isothermal studies have shown that the Fritz-Schlander isotherm with the least error with the experimental data of p-NiO/n-ZnO (5%) photocatalytic degradation are the best fit. پرونده مقاله -
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59 - Synthesis and Characterization of Nanocrystalline Zinc Oxide Thin Films via Green Chemistry
Sharma Bhasha Santosh Singh Purnima Jain Parul MalikGreen chemistry is an alternative route of which has overcome the limitations of other chemical methods. Nanocrystalline zinc oxide (NC-ZnO) with different structures have been grown on quartz plates by spin coating method by the use of plant extracts of Citrus aurantif چکیده کاملGreen chemistry is an alternative route of which has overcome the limitations of other chemical methods. Nanocrystalline zinc oxide (NC-ZnO) with different structures have been grown on quartz plates by spin coating method by the use of plant extracts of Citrus aurantifolia which can be a cost effective and eco-friendly approach.. The present exploration describes the synthesis and characterization of ZnO nanoparticles thin films were characterized by XRD, SEM and AFM and Raman techniques to reveal their structural, morphological and optical details. پرونده مقاله -
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60 - Solvent Selection in Impregnation of Zinc Oxide Nanoparticles into MCM-41 Investigation of Its Ability Toward H2S Removal from Crude Oil
Ali Akbar Miran Beigi Nastaran Hazrati Majid Abdouss Amir VahidSilicate mesoporous materials are of the main interesting adsorbents for decreasing of hydrogen sulfide (H2S) from crude oil. In this work zinc impregnated highly ordered MCM-41 was synthesized via post-synthesis functionalization and was used as adsorbent for removal o چکیده کاملSilicate mesoporous materials are of the main interesting adsorbents for decreasing of hydrogen sulfide (H2S) from crude oil. In this work zinc impregnated highly ordered MCM-41 was synthesized via post-synthesis functionalization and was used as adsorbent for removal of H2S from crude oil. Also the variation of solvents was mainly adjusted. In order to determine the ideal solvent for the synthesis of zinc incorporated MCM-41, a few solvents (water, ethanol and THF) has been tried in these experiments. The experiments showed that THF is a better solvent to get better materials. پرونده مقاله -
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61 - Effect of growth time on ZnO thin films prepared by low temperature chemical bath deposition on PS substrate
Reza Shabannia Nima NaderiZnO thin films were successfully synthesized on a porous silicon (PS) substrate by chemical bath deposition method. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and photoluminescence (PL) analyses were carried out to investigate the effe چکیده کاملZnO thin films were successfully synthesized on a porous silicon (PS) substrate by chemical bath deposition method. X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and photoluminescence (PL) analyses were carried out to investigate the effect of growth duration (3, 4, 5, and 6 h) on the optical and structural properties of the aligned ZnO nanorods. The small FWHM and stronger diffraction intensity of growth times of 5 h mean the better crystal quality of ZnO thin films compared to others. The grain size of the ZnO thin films gradually increased with increased the growth time. The FESEM images show that the thickness of ZnO thin films increased with increase of the growth time. Photoluminescence measurements showed that there was a sharp and highly intense UV emission peak when growth time was 5 h. The structural and optical investigations revealed that the ZnO thin films grown on the PS substrate with growth time of 5 h had high structural and optical quality. پرونده مقاله -
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62 - Photocatalytic degradation of Congo Red dye by using nano ZnO and Ni-Co-ZnO nanocomposites
Sara Poorarjmand Maryam Kargar Razi Ali Reza Mahjoob Morteza KhosraviPhotocatalysis has attracted significant attention as a potential issue for the degradation of toxic organic pollutants such as Congo Red. In this research spherical Pure ZnO nano particles and Ni-Co-ZnO nano composites (Zn0.95Ni0.04Co0.01O, Zn0.95Ni0.025Co0.025O and Zn چکیده کاملPhotocatalysis has attracted significant attention as a potential issue for the degradation of toxic organic pollutants such as Congo Red. In this research spherical Pure ZnO nano particles and Ni-Co-ZnO nano composites (Zn0.95Ni0.04Co0.01O, Zn0.95Ni0.025Co0.025O and Zn0.95Ni0.01Co0.04O) have been synthesized by precipitation method. X- ray diffraction, Fourier transform Infra Red ,field emission scanning electron microscopy, EDX and ICP analysis confirmed the structure and composition of the samples. The x-ray diffraction analysis (XRD) showed that all samples prepared were about Wurtzite structure and average crystal size of 17nm. Field emission scanning electron microscopy (FESEM) analysis revealed the spherical shape of all samples. The Fourier transform infrared spectroscopy (FT-IR) revealed bands at 435 cm-1, 480 cm-1 and 525 cm-1 are related to Zn-O bonds, related to the stretching vibrating bonds of ZnO. The results illustrated the Ni and Co ions substituted the Zn ions in ZnO crystal lattice successfully. The results showed that some of doped Ni-Co ZnO exhibit enhanced photocatalytic activity , as compared to pure ZnO. Kinetic of de-colorization process for all photo-catalysts followed psedu first order. In degradation process The best photocatlyst was (Zn0.95Ni0.04Co0.01O). پرونده مقاله -
دسترسی آزاد مقاله
63 - The removal of Hexavalent chromium; (Cr (VI)) by ZnO/LECA as a nano photocatalyst using full factorial experimental design
Safoora Karimi Aref ShokriIn this research, a synthesized nano photocatalyst was prepared by supportingZnO nanoparticle on Lightweight expanded clay aggregate (LECA). The catalystwas synthesized by the co-precipitation method. The SEM, FT-IR, and XRD testswere used to characterize ZnO/LECA, whic چکیده کاملIn this research, a synthesized nano photocatalyst was prepared by supportingZnO nanoparticle on Lightweight expanded clay aggregate (LECA). The catalystwas synthesized by the co-precipitation method. The SEM, FT-IR, and XRD testswere used to characterize ZnO/LECA, which was employed for photocatalyticremoval of Cr (VI) from an aqueous solution in a batch photoreactor. The fullfactorial experimental design (FFD) was used for the statistical analysis of data.The influence of catalyst amounts, pH, and initial concentration of Cr (VI) wasinvestigated on the reduction of Cr (VI) to Cr (III). The number of active sites wasincreased with an increase in the concentration of catalyst to some extent. Also,the selection of other factors in the optimized amount was important. The optimalconditions were obtained at 0.75 g/l of photocatalyst, pH at 5 and 20 mg/l ofCr(VI). The experimental and predicted reduction efficiency by FFD at optimalconditions were 97.6 and 96.18%, respectively. The comparison of experimentaland predicted data showed a good agreement between them. پرونده مقاله -
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64 - Photocatalytic degradation of Malachite Green using ZnO and ZnOTiO2 nanoparticles from aqueous solution
Hadi Baseri Elahe AlizadehToday, despite the increasing demands for the products of chemical industries and the relatedfactories, the challenges of environmental pollution have not been improved and it is approaching avery dangerous stage. In this regard, the role of dyeing industries in contami چکیده کاملToday, despite the increasing demands for the products of chemical industries and the relatedfactories, the challenges of environmental pollution have not been improved and it is approaching avery dangerous stage. In this regard, the role of dyeing industries in contaminating the environment isundeniable. In this research, ZnO and ZnO-TiO2 nanoparticles were synthesized by co-precipitation andsol-gel methods, respectively. The synthesized nanoparticles were characterized by XRD and FE-SEMtechniques and their band gap energy were determined using the UV-Vis spectrum obtained from thesuspension of nanoparticles. By using synthesized nanoparticles, degradation of malachite green underirradiation of the UV (A) -Visible mixture light from aqueous solution were evaluated and the effect ofdifferent parameters such as amount of photo catalyst, time of light irradiation and dose of H2O2hasbeen studied. The destruction amount was determined by UV-Vis spectroscopy method. Based on thereported results, the maximum degradation efficiency of about 99% was obtained in the optimal valuesof experimental conditions. پرونده مقاله -
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65 - ZnO/WO3 nanocomposites: Pechini sol-gel synthesis, characterization, and photocatalytic performance for desulfurization of thiophene
Nahid Kalhor Mohammad Ghodrati Mehdi Mousavi-KamazaniThe aim of this study was to investigate and overcome thiophene sulfurcontaminants using high purity synthesized ZnO/WO3 nanocomposite andhomogeneous composition by Pechini sol-gel method at low temperature.Zinc oxide is one of the most dynamic elements known in this fi چکیده کاملThe aim of this study was to investigate and overcome thiophene sulfurcontaminants using high purity synthesized ZnO/WO3 nanocomposite andhomogeneous composition by Pechini sol-gel method at low temperature.Zinc oxide is one of the most dynamic elements known in this field, itspresence together with tungsten oxide prevents the crystallization of tungstennanoparticles. Fuzzy structure, percentage of elements, surface morphology,penetration reflection spectrum, and photocatalytic degradation of thiophenewere determined by XRD, EDS, SEM, and DRS analyses, respectively. DRS resultsindicate high light absorption, reduced bandgap due to the presence of WO3 aftercombination with ZnO, and increased efficiency. Finally, the nanocomposite withmore than 84% efficiency resulted in the degradation of oxidative desulfurizationof thiophene after 150 min under visible light. پرونده مقاله -
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66 - Rapid, convenient and solventless green approach for the synthesis of aryloximes using ZnO nanoparticles as an efficient catalyst
Leila Dinparast Hassan ValizadehFreshly prepared ZnO nanoparticles were used as an effective heterogeneous base catalyst for the synthesis of aryloximes. The conversion of arylaldehydes and arylketones into the corresponding oximes (up to quantitative yields) was achieved by simply mixing the liquid r چکیده کاملFreshly prepared ZnO nanoparticles were used as an effective heterogeneous base catalyst for the synthesis of aryloximes. The conversion of arylaldehydes and arylketones into the corresponding oximes (up to quantitative yields) was achieved by simply mixing the liquid reactants and hydroxylamine hydrochloride with ZnO nanoparticles under solvent-free condition. The procedure was carried out under wet conditions for solid reactants. The advantages of this method include mild reaction conditions, one-pot procedure, operational simplicity and use of inexpensive and non-toxic catalyst. پرونده مقاله -
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67 - Enhancement of photocatalytic activity of ZnO–SiO2 by nano-sized Pt for efficient removal of dyes from wastewater effluents
Leila Vafayi Soodabe GharibeIn this work, ZnO/SiO2 nanoparticles were prepared using sol-gel method, and platinum particles were loaded on ZnO/SiO2 nanoparticles by photoreductive method. Samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transfor چکیده کاملIn this work, ZnO/SiO2 nanoparticles were prepared using sol-gel method, and platinum particles were loaded on ZnO/SiO2 nanoparticles by photoreductive method. Samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The XRD patterns showed that the zinc oxide samples have a wurtzite structure (hexagonal phase). The crystallite size calculated by Scheerer’s equation is ~ 32 nm. For photocatalytic test, decomposition of Rhodamine B (RB), as an organic pollutant, was carried out. A comparison of degradation between bare catalyst and platinum loaded ZnO/SiO2 nanoparticle under UV-Vis light irradiation shows that the Pt- ZnO/SiO2 photocatalyst is more efficient than ZnO/SiO2 nanoparticles. Also, the activity of ZnO/SiO2 nanoparticles in the visible light are minimal, while loading of Pt in zinc oxide network displaced the band gap toward longer wavelengths (visible light) and improved the photocatalysis activity of ZnO/SiO2 in the range of visible light. پرونده مقاله -
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68 - Sonosynthesis, characterization and photocatalytic degradation property of nanoZnO/zeoliteA
Shokufeh Aghabeygi Reza Kia Kojoori Hamideh Vakili AzadNano hexagonal wurtzite ZnO has been prepared on zeoliteA by the sono-chemical method. The zeoliteA was mixed into Zinc gel, after stirring for two days, the mixture was irradiated 30 min by ultrasonic probe. The filtrated composite gel was calcinated at 500°C for 3 چکیده کاملNano hexagonal wurtzite ZnO has been prepared on zeoliteA by the sono-chemical method. The zeoliteA was mixed into Zinc gel, after stirring for two days, the mixture was irradiated 30 min by ultrasonic probe. The filtrated composite gel was calcinated at 500°C for 3h in furnace. The produced composite was characterized using X-ray diffraction, FT-IR spectroscopy and field emission scanning electron microscopy. The average crystal size of the nanoZnO and nanoZnO on zeoliteA was determined 53 and 38 nm, respectively. The range of particles size of the nanoZnO on zeoliteA is 30-50 nm. The particles of nanoZnO on the surface of zeoliteA has been dispersed over the zeoliteA framework and the results have shown a higher rate of photodegradation of Congo red (an azo-dye) as compared with bare nanoZnO. پرونده مقاله -
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69 - Enhanced photocatalytic activity of sonochemical derived ZnO via the co-doping process
Maryam Bordbar Solmaz Forghani-pilerood Ali Yeganeh-FaalIn the present study, Co-ZnO and Co-Ni-ZnO nanoparticles were synthesized by sonochemical methods and the structural and optical properties were investigated through Fourier Transform Infrared spectroscopy (FTIR), UV-Vis spectroscopy, Field Emission Scanning Electron Mi چکیده کاملIn the present study, Co-ZnO and Co-Ni-ZnO nanoparticles were synthesized by sonochemical methods and the structural and optical properties were investigated through Fourier Transform Infrared spectroscopy (FTIR), UV-Vis spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM), X-Ray Diffraction (XRD), and Photoluminescence spectroscopy (PL) methods. Morphology of nanoparticles obtained a small granular shape with an average crystallite size of 60 nm. In addition, the direct band gap was calculated using Tauc's approach. Comparing with pure ZnO, the band gap of the doped-ZnO NPs is smaller and depends on the type of dopants. Moreover, photocatalytic activity of all samples was investigated by the degradation of methyl orange (MO) dye under UV irradiation in an aqueous medium. Co-Ni-ZnO possesses excellent photocatalytic activity for the degradation of MO when compared to Co-ZnO and ZnO. In addition, the photocatalytic activity of Co-ZnO improves in the presence of nickel dopant. Moreover, the photocatalyst could be reused for four times without remarkable loss of its activity. پرونده مقاله -
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70 - Synthesis of zinc oxide nanoparticle by zinc acetate precursor and study on its catalytic properties
Azar Bagheri GhomiZnO nanoparticles have been prepared by a simple method in a short period of time. In this synthetic method, the sample was obtained using Zn(CH3COO)2·2H2O and a new template of hexamine salt. Their crystalline structure and morphology were studied by XRD and SEM چکیده کاملZnO nanoparticles have been prepared by a simple method in a short period of time. In this synthetic method, the sample was obtained using Zn(CH3COO)2·2H2O and a new template of hexamine salt. Their crystalline structure and morphology were studied by XRD and SEM. The optical properties of the sample were studied by UV–visible spectroscopy. The absorption spectrum of ZnO shows that the optical band gap is 3.02 eV. In this investigation, the photocatalytic degradation of Indigo carmine(IC) in water was studied. The degradation rate is reduced as a function of increase in the initial concentration of IC. The effects of some parameters such as pH and initial concentration of dye were examined. پرونده مقاله -
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71 - Photocatalytic degradation of phenylephrine hydrochloride in aqueous solutions by synthesized SnO2-doped ZnO nanophotocatalyst
Masoud Giahi Akram Hoseinpour DargahiZnO and SnO2-doped ZnO nanoparticles were prepared by a sol–gel method for the first time. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the ZnO and SnO2-doped ZnO samples. Advanced oxidation processes (AOPs) have proved چکیده کاملZnO and SnO2-doped ZnO nanoparticles were prepared by a sol–gel method for the first time. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the ZnO and SnO2-doped ZnO samples. Advanced oxidation processes (AOPs) have proved very effective in treatment of the various hazardous organic pollutants such as surfactants and pharmaceuticals in water. The photocatalytic degradation of drug phenylephrine hydrochloride (PHE) was studied as model organic pollutant. Under UV exposure the process was investigated with ZnO and SnO2-doped ZnO. The degradation was studied under different conditions including irradiation time, pH, catalyst concentration, phenylephrine hydrochloride concentration and potassium peroxydisulfate as an oxidant. The experimental results indicated that maximum degradation (99.4±1.0%) of drug occurred with SnO2-doped ZnO catalyst. The results demonstrated that photodegradation efficiency of SnO2-doped ZnO was significantly higher than that of undoped ZnO. پرونده مقاله -
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72 - Photocatalytic degradation of ciprofloxacin in the presence of synthesized ZnO nanocatalyst: The effect of operational parameters
Solmaz Aghdasi Mohammad ShokriThis study was aimed at investigating the photocatalytic degradation of ciprofloxacin (CIP) antibiotic in aqueous solution using immobilized ZnO nanoparticles on glass plate. X-ray diffraction, atomic force microscopy, and scanning electron microscopy were applied to ch چکیده کاملThis study was aimed at investigating the photocatalytic degradation of ciprofloxacin (CIP) antibiotic in aqueous solution using immobilized ZnO nanoparticles on glass plate. X-ray diffraction, atomic force microscopy, and scanning electron microscopy were applied to characterize the nanoparticles. To do so, the ZnO nanoparticles were synthesized through the chemical precipitation method and were immobilized on a glass plate. The degradation of CIP was under UV-C light irradiation. The effects of operational parameters (initial concentration of CIP, pH, and light intensity) on the activity of synthesized ZnO photocatalyst and the kinetics of reaction were investigated. With the initial concentration of 10 mg L-1 of CIP, pH = 6.8 and light intensity = 42 W m-2, the photodegradation efficiency was found to be 69.5%. The results showed that the reaction followed a pseudo-first-order kinetic. The results of the mineralization studies also represented a decreasing trend of total organic carbon over time. پرونده مقاله -
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73 - Effects of metal oxide catalysts on the photodegradation of antibiotics effluent
Chaimaa EL Bekkali Habiba Bouyarmane Said Laasri Abdelaziz Laghzizil Ahmed SaoiabiThe current study examined the effect of metal oxide catalysts on the sorption and photocatalytic efficiencies for the removal of ciprofloxacin and ofloxacin in water. ZnO and TiO2 catalysts are prepared using a suitable method based on the sol-gel process, which have a چکیده کاملThe current study examined the effect of metal oxide catalysts on the sorption and photocatalytic efficiencies for the removal of ciprofloxacin and ofloxacin in water. ZnO and TiO2 catalysts are prepared using a suitable method based on the sol-gel process, which have a great change in structural and textural properties. The structure and surface area of the synthesized catalysts were characterized, and used as sorbents/catalysts to remove antibiotics from water. Results showed a high adsorption capacity for the Titania oxide related to its great surface area, it is about 280 m2 g-1, compared to that of ZnO catalyst with only 19 m2 g-1. However, both photocatalysts exhibit a difference in photocatalytic activity versus both drugs. Therefore, ZnO, as a competitor catalyst for the TiO2, provides the most effective treatment of contaminated water with antibiotic pollutants to produce suitable reused water. پرونده مقاله -
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74 - Optical and photocatalytic properties Undoped and Mn-doped ZnO nanoparticles synthesized by hydrothermal method: Effect of annealing temperature
Maryam Bordbar Seyed Mohammad Vasegh Somaye Jafari Ali Yeganeh FaalUndoped and Mn-doped ZnO nanoparticles were successfully prepared by the hydrothermal method with different annealing temperature conditions. Structural, chemical and optical properties of the samples were studied by X-ray diffraction (XRD), Field Emission scanning elec چکیده کاملUndoped and Mn-doped ZnO nanoparticles were successfully prepared by the hydrothermal method with different annealing temperature conditions. Structural, chemical and optical properties of the samples were studied by X-ray diffraction (XRD), Field Emission scanning electron microscopy (FESEM), UV-Vis spectrophotometry and Fourier transform infrared (FT-IR) spectroscopy. The phase purity was confirmed by X-ray powder diffraction (XRD) and XRD spectra showed that all the samples were hexagonal wurtzite structure and as the annealing temperature increases the material becomes less crystalline. In addition, the average crystal size was found to be 15-30 nm from SEM and XRD. It is seen that the optical band gap increases when the ZnO is doped with manganese and decreases when annealing temperature increases. The photoacatalytic activity of Undoped and Mn-doped ZnO nanoparticles was tested by the degradation of metyl orang (MO) under UV light and indicated that Mn-doped ZnO has higher photocatalytic activity relative to ZnO nanoparticles and photocatalytic activity decreases when annealing temperature increases. پرونده مقاله -
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75 - Sonochemical synthesis of undoped and Co-doped ZnO nanostructures and investigation of optical and photocatalytic properties
Bahar Khodadadi Maryam BordbarIn this paper, undopedZnO and Co-ZnOnano structureswith different molar ratio of Cobalt have been synthesized by the sonochemical method. Structure have been characterized by Fourier Transform (FTIR) and UV–Vis spectroscopy,Scanning Electron Microscopy (SEM), Ener چکیده کاملIn this paper, undopedZnO and Co-ZnOnano structureswith different molar ratio of Cobalt have been synthesized by the sonochemical method. Structure have been characterized by Fourier Transform (FTIR) and UV–Vis spectroscopy,Scanning Electron Microscopy (SEM), Energy Dispersive Analytical X-Ray (EDAX), and X-Ray Diffraction (XRD) methods. Moreover, the direct band gap has been calculated by Tauc’s approach.Moreover, mean crystal size has been estimated by Scherrerequaton. Furthermore, photocatalytic activity for all samples has been investigated under UV irradiation in an aqueous medium. Compared with pure ZnO, the band gap of the Co-ZnOhas been shown decrease and it is dependent on the content of dopants. Also, photocatalytic activity improves in the presence of cobalt dopant. پرونده مقاله -
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76 - Incorporation of Pb2+, Fe2+ and Cd2+ ions in ZnO nanocatalyst for photocatalytic activity
Maryam Bordbar Zahra Sayban Ali Yeganeh-Faal Bahar KhodadadiIn the present study, Pb-ZnO, Fe-ZnO, Cd-ZnO and Pb-Fe-Cd-ZnO nanoparticles were synthesized by the sonochemical method and those structural and optical properties were investigated by Fourier Transform Infrared spectroscopy (FTIR), UV-Vis spectroscopy, Field Emission S چکیده کاملIn the present study, Pb-ZnO, Fe-ZnO, Cd-ZnO and Pb-Fe-Cd-ZnO nanoparticles were synthesized by the sonochemical method and those structural and optical properties were investigated by Fourier Transform Infrared spectroscopy (FTIR), UV-Vis spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM) and X-Ray Diffraction (XRD). Average crystallite size obtained was 60 nm. Moreover, the direct band gap has been calculated using Tauc's approach. Compared with pure ZnO, the band gap of the doped-ZnO NPs is smaller and it depends on the type of dopants. In addition, photocatalytic activity of all samples has been investigated by the degradation of congo red (CR) dye under UV irradiation in an aqueous medium. In the presence of ZnO NPs photocatalytic degradation of 35% was obtained for 180 min. But Pb-ZnO, Fe-ZnO, Cd-ZnO and Pb-Fe-Cd-ZnO have shown the degradation of 45, 57, 65 and 80% respectively; they have the faster decolorization as compared with the ZnO NPs. Moreover, the photocatalyst could be reused for five times without remarkable loss of its activity. پرونده مقاله -
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77 - Graphene–ZnO@SiO2 hybrid: An efficient and solid acid catalyst for synthesis of azlactones under ultrasound irradiation
Sodeh SadjadiThe central theme of this article is how to explore a novel route to fabricate graphene– ZnO@SiO2 hybrid by a covalent process. The synthesis procedure consists of three-steps: (1) synthesis of ZnO nanoparticles, (2) ZnO nanoparticles modification by tetraethyl or چکیده کاملThe central theme of this article is how to explore a novel route to fabricate graphene– ZnO@SiO2 hybrid by a covalent process. The synthesis procedure consists of three-steps: (1) synthesis of ZnO nanoparticles, (2) ZnO nanoparticles modification by tetraethyl orthosilicate and (3-aminopropyl) triethoxysilane after introduction of amino groups on its surface, (3) the covalent attachment of ZnO@SiO2 onto the graphene surface by the amidation reaction between amino group of ZnO@SiO2 and carboxylic group of graphene. This hybrid was then used as a catalyst for the synthesis of azlactones obtained by Erlenmeyer synthesis from aromatic aldehydes and hippuric acid under the ultrasonic irradiation. The protocol offers advantages in terms of higher yields, short reaction times, mild reaction conditions, and reusability of the catalyst. پرونده مقاله -
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78 - Photocatalytic degradation of methyl orange using ZnO and Fe doped ZnO: A comparative study
Kalpesh Anil Isai Vinod Shankar ShrivatavaZnO and 2% Fe doped ZnO photocatalytic nanomaterials were successfully synthesized by successive ionic layer adsorption and the reaction (SILAR) method. The characterizations of these nanomaterials were carried out using XRD, SEM and EDX techniques. XRD study shows that چکیده کاملZnO and 2% Fe doped ZnO photocatalytic nanomaterials were successfully synthesized by successive ionic layer adsorption and the reaction (SILAR) method. The characterizations of these nanomaterials were carried out using XRD, SEM and EDX techniques. XRD study shows that the samples have a hexagonal wurtzite crystalstructure, size of which is in the range 21-23 nm. SEM shows nanoflakes or nano flower-like morphology, while EDX reveals the compositional analysis. In this paper, we investigated photocatalytic degradation of an aqueous suspension of methyl orange (MO) dye as a model pollutant. Degradation of dye was monitored by the spectrophotometric method. The effects of various parameters such as pH, contact time, initial dye concentration and catalyst dose were studied. in optimized process, the maximum degradation obtained using ZnO was 88 % and that using Fe doped ZnO was 94 % at a pH value of 8. We have concluded that, compared to ZnO, the 2% Fe doped ZnO is a promising photocatalyst for degradation of MO. پرونده مقاله -
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79 - Preparation of ZnO nanocatalyst supported on todorokite and photocatalytic efficiency in the reduction of chromium (VI) pollutant from aqueous solution
Maryam Sabonian Kazem MahanpoorIn this research, a new effective photocatalyst was prepared by supporting ZnO on a Todorokite (TD). This catalyst was characterized by employing scanning electron microscopy (SEM-EDX) and X-Ray Diffraction (XRD) patterns. The optical properties of the samples were meas چکیده کاملIn this research, a new effective photocatalyst was prepared by supporting ZnO on a Todorokite (TD). This catalyst was characterized by employing scanning electron microscopy (SEM-EDX) and X-Ray Diffraction (XRD) patterns. The optical properties of the samples were measured by diffuse reflectance spectroscopy (DRS). The purpose of using the ZnO/TD as a photocatalyst was to reduction Cr(VI), which is a pollutant in water. Experiments were carried out under different operating conditions including an initial concentration of Cr(VI), photocatalyst amounts and pH values. To optimize processes and obtain a mathematical model, the researcher used a full factorial design (with three factors at three levels). The optimal conditions were determined where the amount of photocatalyst= 200 mg L-1, pH= 2 and concentration of Cr(VI)= 15 ppm. The reduction efficiency in an optimal condition was 97.73%. The experimental results showed that kinetic was the first order and k= 0.1489 min–1. پرونده مقاله -
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80 - Enhancement of photocatalytic degradation of 4-nitrophenol by integrating Ag nanoparticles with ZnO/HZSM-5 nanocomposite
Baharak Divband Azadeh Jodaei Masumeh KhatamianIn this paper, Ag/ZnO/HZSM-5ternary nanocomposites with different Ag loadings were prepared by the photo precipitation method. The prepared photocatalysts were characterized by XRD, BET, SEM and TEM. The photocatalytic activity of ZnO/HZSM-5 for 4-nitrophenol (4-NP) deg چکیده کاملIn this paper, Ag/ZnO/HZSM-5ternary nanocomposites with different Ag loadings were prepared by the photo precipitation method. The prepared photocatalysts were characterized by XRD, BET, SEM and TEM. The photocatalytic activity of ZnO/HZSM-5 for 4-nitrophenol (4-NP) degradation was increased by silver doping. Effects of various parameters such as the initial concentration of 4-NP, pH and Ag loading on 4-NP degradation were studied. The best activities were obtained for the 3% Ag-10% ZnO/HZSM-5 nanocatalysts at pH 7.9, 1 g L−1 of the catalyst and 5 ppm of 4-NP. Langmuir–Hinshelwood (L–H) model was proposed for the rate equation of the 4-NP degradation. پرونده مقاله -
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81 - Properties of sol-gel synthesized multiphase TiO2 (AB)-ZnO (ZW) semiconductor nanostructure: An effective catalyst for methylene blue dye degradation
Manikandan Balakrishnan Rita JohnThe present study, describes the structural, electrical, and the photocatalytic activity of sol-gel synthesized TiO2- ZnO nanostructure. The synthesized mixed oxide nanostructure is characterized by XRD, FTIR, Raman, UV-Vis, FESEM, DLS and Impedance Spectroscopy analyse چکیده کاملThe present study, describes the structural, electrical, and the photocatalytic activity of sol-gel synthesized TiO2- ZnO nanostructure. The synthesized mixed oxide nanostructure is characterized by XRD, FTIR, Raman, UV-Vis, FESEM, DLS and Impedance Spectroscopy analyses. In addition, photocatalytic activity of multiphase TiO2 (TAB)-ZnO (ZW) nanostructure is analysed using Methylene Blue dye as the model dye under UV and Visible light illumination. The XRD analysis confirms the bi-phase TiO2 and mono-phase ZnO in the multiphase TiO2-ZnO nanostructures. The average crystallite size of 33 nm has been estimated using Scherrer formula. The crystallite size and mechanical properties such as strain, stress, and other parameters are analysed using Williamson-Hall model. The FTIR spectrum shows the characteristics absorption peaks of TiO2 and ZnO at 679.44 and 432.79 cm-1 respectively, and reveals the presence of TiO2 and ZnO in the synthesized multiphase nanostructure. The optical band gap is calculated using Tauc relation with the data obtained from UV-Vis spectrometer. The calculated band gap value is 3.1 eV. The FESEM study shows the spherical morphology and the DLS analysis confirms the particle size is 433 nm. The presence of Ti-O and Zn–O stretching modes are confirmed from Raman spectrum. The electrical properties such as dielectric constant, dielectric loss, and ac conductivity are analysed from impedance data. The prepared multiphase TiO2 (TAB)-ZnO (ZW) nanostructure shows better photocatalytic activity in both UV and visible light region. The rate constant has been calculated as 0.0083 and 0.0052 min-1 for UV and visible light irradiation. پرونده مقاله -
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82 - Applying Taguchi method to optimize the synthesis conditions of ZrO2/TiO2/ZnO nanocomposite for high-performance photodegradation of Congo red
Toktam Seyedi-Chokanlou Shokufeh Aghabeygi Nasibeh Molahasani Fahimeh AbrinaeiIn this work, ZrO2/TiO2/ZnO ternary nanocomposites were prepared by the sol-gel technique. The Taguchi method with the L9 orthogonal array was utilized to optimize the experimental conditions for the preparation of nanocomposites. The design has four factors, and each f چکیده کاملIn this work, ZrO2/TiO2/ZnO ternary nanocomposites were prepared by the sol-gel technique. The Taguchi method with the L9 orthogonal array was utilized to optimize the experimental conditions for the preparation of nanocomposites. The design has four factors, and each factor has three levels. The design factors of this study were calcination temperature, the aging time, the calcination time, and ultrasonic irradiation duration. Furthermore, as-synthesized structural features of nanocomposites were characterized, utilizing XRD, BET, FESEM, and EDX. The photocatalytic activities of all ZrO2/TiO2/ZnO nanocomposites were evaluated by the photodegradation of Congo red (CR) as an azo dye. The photocatalytic property of nanocomposites was enhanced by decreasing particle size and increasing the surface area. The best sample photodegraded 97% the CR solution within 15 min under an 8W UV lamp. The optimal conditions were achieved as 400 ºC calcination temperature, 72 h aging time, 4 h calcination time, and 30 min duration of ultrasonic irradiation for CR solution photodegradation. The effect of each parameter was evaluated using ANOVA analysis. The kinetics results showed the pseudo-first-order reaction mechanism for the photocatalytic activities of the nanocomposites. پرونده مقاله -
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83 - A simple synthetic technique to produce ZnO/Fe2O3/Fe3O4 nanostructures and application as a photocatalyst
Nai-Feng Hsu Kuei-Ting HsuIn this study, a simple technique was used for synthesizing one-dimensional ZnO/Fe2O3/Fe3O4 nanostructures (NSs) through heat treatment under vacuum by using a magnetic field at a temperature of 200 °C for 1 h. The photocatalytic effect of the NSs were studied by de چکیده کاملIn this study, a simple technique was used for synthesizing one-dimensional ZnO/Fe2O3/Fe3O4 nanostructures (NSs) through heat treatment under vacuum by using a magnetic field at a temperature of 200 °C for 1 h. The photocatalytic effect of the NSs were studied by decomposing methyl orange (MO) dye (5 mg/L, pH = 8.1) under ultraviolet illumination. The experimental results indicated that a 33-mg/L ZnO/Fe2O3/Fe3O4 NS-containing film on glass could reduce the MO concentration by 37% in 100 min, and the synthesized ZnO/Fe2O3/Fe3O4 NS-containing films could be reused to degrade MO solution. Moreover, 0.1 g/L of ZnO/Fe2O3/Fe3O4 NS-containing powder exhibited an excellent photocatalytic effect and reduced the MO concentration by almost 90% in 100 min. پرونده مقاله -
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84 - Porous and Bifunctional ZnO-Hydroxyapatite Nanostructure for Photocatalytic Degradation of Paracetamol and Methylene Blue in Water
Jihane Labrag Chaimaa El Bekkali Abdeladim Oulguidoum D. Robert Abdelaziz Laghzizil J. M. NunziPorous ZnO-hydroxyapatite nanocomposite was prepared by dissolution of a rock phosphate ore in an acidic medium followed by alkaline precipitation. Its photocatalytic activity was assessed for the degradation of paracetamol as one of the most commonly prescribed pharmac چکیده کاملPorous ZnO-hydroxyapatite nanocomposite was prepared by dissolution of a rock phosphate ore in an acidic medium followed by alkaline precipitation. Its photocatalytic activity was assessed for the degradation of paracetamol as one of the most commonly prescribed pharmaceutical drugs and methylene blue as dye model. Thanks to its good porosity, the 40ZnHAp nanocomposite adsorbed the selected pollutants better than the individual ZnO and HAp phases. 40ZnHAp calcined at 500° completely degrades the studied pollutants faster than ZnO, although a longer illumination time is required for the degradation of paracetamol. The low-cost 40ZnHAp nanomaterial can be considered as a potential photocatalyst for wastewater treatment due to its high porosity, which facilitates the entrapment of initial pollutants and/or by-products. It leads to a complete mineralization, consequently yielding healthy discharged water. پرونده مقاله -
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85 - Removal of Mercury (II) in Aqueous Solution by Using ZnO and ZnO/CdS Nanoparticles as Photocatalysts
Fattima Al-Zahra Gabar Gassim Ali J. J. Makkaw Noor Hadi AysaZinc oxide (ZnO) and ZnO/CdS nanoparticles have been synthesized. The samples were characterized by Fourier transform infrared spectroscopy (FT–IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Photocatalytic reduction of toxic Hg (II) in aqueo چکیده کاملZinc oxide (ZnO) and ZnO/CdS nanoparticles have been synthesized. The samples were characterized by Fourier transform infrared spectroscopy (FT–IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Photocatalytic reduction of toxic Hg (II) in aqueous solutions by suspension ZnONPs and ZnO/CdSNPs has been studies under an oxygen atmosphere. Flame atomic absorption (AFM) has been used to determine the concentration of Hg (II) in aqueous solutions. Photocatalytic reduction of Hg (II) was carried out with various ZnO nanoparticles (ZnONPs) concentrations. The optimum concentration of ZnO NPs was obtained at 0.24 mg/L. The highest photo reduction rate was obtained at 0.24 mg/ZnO/CdSNPs concentration. According to the experimental results, the reaction mechanism of ZnONPs and ZnO/CdSNPs illumination to produce oxidizing species and the effect of these species on the Hg (II) in aqueous solution has been suggested. پرونده مقاله -
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86 - Optimization of Photo Catalytic Activity of ZnO Nano Composites by Surface Modification with Cu metal using Facile Hydrothermal Approach
Fazal Ur Rehman Manzar Zahra Iqra Qayyum Aoun Raza Amir WaseemZnO nano particles and Cu modified ZnO nano composites have been prepared by simple, facile hydrothermal approach. The novelty of this work was the use of aqueous methanolic solution (50:50 ratio) as the solvent of reaction, while zinc chloride was used as the precursor چکیده کاملZnO nano particles and Cu modified ZnO nano composites have been prepared by simple, facile hydrothermal approach. The novelty of this work was the use of aqueous methanolic solution (50:50 ratio) as the solvent of reaction, while zinc chloride was used as the precursor of ZnO NPs and Cu- modified ZnO nano composites. XRD results revealed that the synthesized ZnO and Cu-modified ZnO nano composites were of nano size and XRD patterns matched with JCPDS Card 35-1451, confirming the synthesis of ZnO nanoparticles. The FT-IR results confirmed the synthesis of target materials and also the adsorption of Cu metal on ZnO surface. The UV visible spectroscopic analysis indicated that the optical properties improved as the concentration of Cu metal increased on ZnO surface. SEM analysis explored the spherical shape of synthesized nano composites. The EDX graph showed the elemental composition of prepared materials that composed of Zn, O and Cu and no other impurity was found. The Tartrazine Yellow Azo Dye was degraded to investigate the photo catalytic activity which was optimized under sunlight with increasing the Cu metal concentration on surface of ZnO. پرونده مقاله -
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87 - Synthesis and Characterization ZnO-Fe2O3 Nanocomposite with Thermal Plasma Method
Mohamad Reza Alikhani Shahrooz Saviz Amir Hossein SariIn the present paper, a novel thermal plasma method is proposed to synthesize ZnO-Fe2O3 nanocomposite, with different percentages of iron, namely 3, 5, and 7%. This method is an efficient feasibility of the Zno-Fe2O3 nanocomposite synthesis. The nanocomposites are synth چکیده کاملIn the present paper, a novel thermal plasma method is proposed to synthesize ZnO-Fe2O3 nanocomposite, with different percentages of iron, namely 3, 5, and 7%. This method is an efficient feasibility of the Zno-Fe2O3 nanocomposite synthesis. The nanocomposites are synthesized by homemade direct current (DC) plasma torch. They are analyzed by different methods. The bandgap is determined by diffuse reflectance spectroscopy (DRS). The photocatalytic performance of Zno-Fe2O3 is evaluated. The results show that the structure of nanoparticles is spherical, which is more favored in the industry. Also, the particle size distribution is uniform. The average size of nanoparticle crystals increases with increasing iron content. Despite the formation of nanocomposites, due to the lack of support for nanoparticles, the results of photodegradation are not satisfactory. پرونده مقاله -
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88 - The most important parameters that affect the photocatalytic activity of ZnO nanostructures against organic dyes: A Review
Marwa Jawad Kadhim Mazin Auny Mahdi Abbas Mohammed Selman Salwan Kamal Jamel Al-Ani Jalal Jabar Hassan Naser Mohammed AhmedOrganic dyes are among the main sources of water pollution that cause serious health problems for living organisms. Removing dye pollution from water sources is important because of its high toxicity, so it has attracted the interest of researchers. Heterogeneous photoc چکیده کاملOrganic dyes are among the main sources of water pollution that cause serious health problems for living organisms. Removing dye pollution from water sources is important because of its high toxicity, so it has attracted the interest of researchers. Heterogeneous photocatalysis based on ZnO is one of the most important methods of pollution treatment. The purpose of this review is to summarize the use of ZnO nanostructure and ZnO modified as photocatalysts.The studied mechanism of dye photocatalytic activity and the most important factors affecting the photocatalytic process are discussed. The major effective parameters associated with the surface and morphology to look upon for the efficient photodegradation of organic pollution are structural and average particle size, surface area, band gap crystalline structure, surface density, and porosity. The photodegradation reactions depend on the state of ionization as well as on the surface charge of the photocatalyst and organic dye because pH will determine the charge of the catalyst according to the medium. On the other hand, the calcination temperature was increased throughout the work to break down the pores, which reduces the surface area of the synthesis photocatalyst. The type of dye has an important influence on the success of the photocatalytic process. پرونده مقاله -
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89 - ZnO nanoparticles as an Efficient and Reusable Catalyst for Synthesis of Quinoxaline under Solvent Free Condition
Bahareh Sadeghi Fereshteh Karimi1,2-Diketones have been reacted in one-pot method with 1,2-diamines at room temperature with ZnO nanoparticles as a catalyst. ZnO nanoparticles as an available and reusable catalyst is used for the synthesis of Quinoxalinein improved yields.1,2-Diketones have been reacted in one-pot method with 1,2-diamines at room temperature with ZnO nanoparticles as a catalyst. ZnO nanoparticles as an available and reusable catalyst is used for the synthesis of Quinoxalinein improved yields. پرونده مقاله -
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90 - Efficient one-pot synthesis of pyrazoles catalyzed by nano-crystalline solid acid catalyst
Abbas Teimouri Alireza Najafi Chermahini Leila GhorbanianAn efficient and green protocol for the synthesis of pyrazoles derivatives by one-pot reaction of different 1,3-dicarbonyl compounds with hydrazines/hydrazides has been developed using nano-sulfated zirconia, nano-structured ZnO, nano-g-alumina and nano-ZSM-5 zeolites, چکیده کاملAn efficient and green protocol for the synthesis of pyrazoles derivatives by one-pot reaction of different 1,3-dicarbonyl compounds with hydrazines/hydrazides has been developed using nano-sulfated zirconia, nano-structured ZnO, nano-g-alumina and nano-ZSM-5 zeolites, as the catalyst. The optical properties of the nano-structured catalysts and organic molecules were studied. The advantages of methods are short reaction times and milder conditions, easy work-up and purification of products by non-chromatographic methods. The catalysts can be recovered for subsequent reactions and reused without any appreciable loss of efficiency. پرونده مقاله -
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91 - Photocatalytic degradation of an azo textile dye with manganese-doped ZnO nanoparticles coated on glass
Mohammad Habibi Elham AskariMn doped ZnO nanocomposite thin film coated on glass by a simple spin-coating method was used to degrade an azo textile dye from aqueous environment. Mn doped ZnO nanocomposite thin film was characterized by means of X-ray diffraction (XRD) and scanning electron microsc چکیده کاملMn doped ZnO nanocomposite thin film coated on glass by a simple spin-coating method was used to degrade an azo textile dye from aqueous environment. Mn doped ZnO nanocomposite thin film was characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photo-reduction activity of photocatalyst was evaluated using an azo textile dye as organic contaminant irradiated only with UV light from mercury bulb. The processing parameter such as the pH value also played an important role in tuning the photocatalytic activity. The maximum photodecomposition rate was achieved at pH=6, and a novel model about the absorption of azo dye on the surface of the catalysts was proposed. پرونده مقاله -
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92 - NanoZnO as an efficient & reusable catalyst for the preparation of 1,4-DHPs via Hantzsch reaction
Fatemeh Tamaddon Somayeh MoradiEasily prepared nanoZnO was found to be as an efficient catalyst in the synthesis of 1,4-DHPs via four-component reaction of 1,3-dicarbonyls, aldehydes and ammonium carbonate in water at 60 °C. The prepared nanoZnO was characterized by XRD and FT-IR analysis, while چکیده کاملEasily prepared nanoZnO was found to be as an efficient catalyst in the synthesis of 1,4-DHPs via four-component reaction of 1,3-dicarbonyls, aldehydes and ammonium carbonate in water at 60 °C. The prepared nanoZnO was characterized by XRD and FT-IR analysis, while the determined specific surface area of nano catalyst by BET method was 33 m2/g. پرونده مقاله -
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93 - Preparation, characterization and determination of photocatalytic activity of MCM-41/ZnO and MCM-48/ZnO nanocomposites
Hamid Reza Pouretedal Mina AhmadiThe direct and indirect methods in solvent media and grinding method in a solvent-free media were used to prepare the MCM-41/ZnO and MCM-48/ZnO photocatalysts. The X-ray diffraction (XRD) patterns showed that zinc oxide nanoparticles were put into MCM-41 and MCM-48 subs چکیده کاملThe direct and indirect methods in solvent media and grinding method in a solvent-free media were used to prepare the MCM-41/ZnO and MCM-48/ZnO photocatalysts. The X-ray diffraction (XRD) patterns showed that zinc oxide nanoparticles were put into MCM-41 and MCM-48 substrates and there were ZnO crystallites as secondary phase in the extra framework of mesoporous materials. The decrease of surface areas, pore volume and average pore size of mesoporous materials with incorporation of ZnO nanoparticles were confirmed by N2 adsorption and desorption isotherms. The FT-IR spectra showed an absorption peak at 490 cm-1 that was related to formation of ZnO in the substrate of MCMs. The photocatalytic activity of MCM-41/ZnO and MCM-48/ZnO were studied in photodegradation reaction of Congo red as a dye pollutant. The photocatalysts of MCM-41/ZnO and MCM-48/ZnO which were prepared by grinding method showed the highest photocataltyic activity with pseudo first-order kinetic rate constants of 34.6 and 27.810-3 min-1, respectively. The obtained results indicated complete incorporation of zinc ions in mesoporous material of MCMs in a solvent-free media. The elimination of solvent and facility of proposed method were the advantages of grinding method in preparation of MCM/ZnO photocatalyst. پرونده مقاله -
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94 - احیا فوتوکاتالیستی کارآمدکروم شش ظرفیتی با استفاده از نانوکریستال های تثیبت شده ی ZnO تحت تابش نور: UV اثر هم افزایی زئولیت HZSM-5 به عنوان پایه
محسن حقیقی فرهاد رحمانی روح اله دهقانی اشرف مظاهری محمد باقر میران زادهفرایندهای فوتوکاتالیستی به عنوان یک روش کارآمد میتواند برای تصفیه فاضلاب های حاوی فلزات سنگین به کار گرفته شود. مطالعه حاضر با هدف سنتزنانوکاتالیست ZnO ‎ برپایه HZSM-5 ‎ و بررسی ویژگی فوتوکاتالیستی آن درکاهش موثر (Cr(VI انجام پذیرفت. نانوکامپوزیت ZnO/HZSM-5 ب چکیده کاملفرایندهای فوتوکاتالیستی به عنوان یک روش کارآمد میتواند برای تصفیه فاضلاب های حاوی فلزات سنگین به کار گرفته شود. مطالعه حاضر با هدف سنتزنانوکاتالیست ZnO ‎ برپایه HZSM-5 ‎ و بررسی ویژگی فوتوکاتالیستی آن درکاهش موثر (Cr(VI انجام پذیرفت. نانوکامپوزیت ZnO/HZSM-5 به روش آب گرمایی/تلقیح سنتز شد و ماهیت آن با روش های XRD، FESEM ،EDX وBET مورد بررسی قرار گرفت. نتایج به دست آمده از تجزیه XRD وجود ZnO و HZSM-5 را به عنوان فاز بلوری در ساختار نانوکامپوزیت تایید کرد. تصاویر FESEM نشان داد نانوذرات ZnO به صورت یکنواخت در سطح زئولیت پخش شده است. تاثیر pH و غلظت اولیه کروم شش ظرفیتی بروی فرایند مورد بررسی قرار گرفت. نتایج مشخص کرد که کارایی حذف کروم شش ظرفیتی با کاهش pHو غلظت اولیهی کروم افزایش می یابد. در نهایت نتایج به دست آمده از بررسی سینتیک نشان داد که با افزایش pH از 3 به 7 ثابتسرعتواکنش از 019/0 به 007/0 بر دقیقه کاهش مییابد و فرایند از واکنش های شبه درجه یک پیروی میکند. بنابراین، فرایند فوتوکاتالیستی با استفاده از نانوکامپوزیت ZnO/HZSM-5 میتواند به عنوان یک روش موثر و سازگار با محیط زیست به منظور تصفیهی فاضلاب های حاوی مقادیر بالای کروم شش ظرفیتی مورد استفاده قرار گیرد. پرونده مقاله -
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95 - تأثیر نسبت اوره به نیترات در سنتز احتراقی نانوکاتالیست CuO/ZnO/Al2O3 برای استفاده در تولید هیدروژن از متانول
رضا شکرانی محمد حقیقی حسین عجمین مظفر عبدالهیفرنانوکاتالیست CuO/ZnO/Al2O3 به وسیلهی روش سنتز احتراقی اوره- نیترات با دو نسبت متفاوت اوره به نیترات 1 و 2 تهیه شدند. نانوکاتالیستهای سنتزی در فرایند تبدیل متانول در حضور بخار آب برای تولید هیدروژن مورد ارزیابی قرار گرفتند. ویژگی فیزیکی و شیمیایی نمونههای سنتزی با است چکیده کاملنانوکاتالیست CuO/ZnO/Al2O3 به وسیلهی روش سنتز احتراقی اوره- نیترات با دو نسبت متفاوت اوره به نیترات 1 و 2 تهیه شدند. نانوکاتالیستهای سنتزی در فرایند تبدیل متانول در حضور بخار آب برای تولید هیدروژن مورد ارزیابی قرار گرفتند. ویژگی فیزیکی و شیمیایی نمونههای سنتزی با استفاده از روشهای XRD ،FESEM ،BET و FTIR بررسی شدند. نتیجههای به دست آمده از EDX و FESEM وجود ذرات پراکنده تر و ریزتر در سطح نمونه با نسبت U/N برابر با 1 را نشان دادند. نتیجههای BET نشان داد که با افزایش مقدار اوره مساحت سطح ویژه افزایش یافته است ارزیابیهایی عملکرد کاتالیستی در فرایند تبدیل متانول با بخار آب نیز نشان داد که نانوکاتالیست با نسبت U/N برابر با 1 هم در تبدیل بالای متانول و هم در تولید اندک CO عملکرد بهتری از خود نشان داده است. در ارزیابی پایداری نیز این کاتالیست به مدت 30 ساعت در فرایند پایدار ماند. پرونده مقاله -
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96 - Effects of Active Packaging Based on Potato Starch/Nano Zinc Oxide/Fennel (Foeniculum vulgare Miller) Essential Oil on Fresh Pistachio during Cold Storage
Hamid Babapour Hossein Jalali Abdorreza Mohammadi Nafchi Maryam JokarThe purpose of this study was to evaluate the effects of a combination of zinc oxide nanoparticles (Nano-ZnO) and fennel essential oil (FEO) on the quality characteristics of fresh pistachio. The potato starch-based films containing different levels of Nano-ZnO (1, 3, a چکیده کاملThe purpose of this study was to evaluate the effects of a combination of zinc oxide nanoparticles (Nano-ZnO) and fennel essential oil (FEO) on the quality characteristics of fresh pistachio. The potato starch-based films containing different levels of Nano-ZnO (1, 3, and 5% w/w), and FEO (1, 2, and 3% w/w) were prepared by the casting method. The fresh Akbari pistachios were packed in these bio-nanocomposite films. The physicochemical and sensory properties and the growth of Aspergillus flavus and aflatoxin B1 production were investigated during 15 days of refrigerated storage (~ 4°C). Results showed that by packaging fresh pistachios in bio-nanocomposite films, the moisture, carbohydrate, and fat contents of pistachios and the sensory parameters (texture, flavor, appearance, and overall acceptability) of them were improved during refrigerated storage. The weight loss of control significantly was higher than packed samples in bio-nanocomposite films (p<0.05). Usage of bio-nanocomposite films leads to a decrease in the growth of Aspergillus flavus and aflatoxin production in pistachios during storage periods. Finally, the results demonstrated that potato starch/5% Nano-ZnO/3% FEO bio-nanocomposite film improved the physicochemical and sensory properties and had the best effect on mold spoilage reduction of fresh pistachios; hence, it can be used as packaging for fresh nuts. پرونده مقاله -
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97 - Study of Methyl tert-butyl Ether (MTBE) Photocatalytic Degradation with UV/TiO2-ZnO-CuO Nanoparticles
Mohsen Mansouri Mohsen Nademi Mohammad Ebrahim Olya Hossein LotfiIn this study, the TiO2-ZnO-CuO nanoparticles were primed by sol-gel method characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM), for degradation of MTBE solution in water. The effectiveness of the treatment method applied for the degradation چکیده کاملIn this study, the TiO2-ZnO-CuO nanoparticles were primed by sol-gel method characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM), for degradation of MTBE solution in water. The effectiveness of the treatment method applied for the degradation of MTBE based on an advanced photocatalytic oxidation process was investigated. The three various key parameters were optimized using response surface modeling namely: pH, TiO2-ZnO-CuO concentration and the initial MTBE concentrations. The optimized values were obtained at the PH (7), TiO2-ZnO-CuO concentration (1.49 g/L), and the initial MTBE concentration (31.46 mg/L). Finally, kinetics reaction of degradtion MTBE was carried in the optimum conditions. پرونده مقاله -
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98 - The Effects of ZnOnanorodson the Characteristics of Sago Starch Biodegradable Films
R. Alebooyeh A. MohammadiNafchi M. Jokr: Nowadays tend to use biodegradable packaging; including edible coatings and films for free from synthetic chemicals and do not cause environmental pollution, the industry is growing day by day. The aim of this research was to preparation and characterization of biodeg چکیده کامل: Nowadays tend to use biodegradable packaging; including edible coatings and films for free from synthetic chemicals and do not cause environmental pollution, the industry is growing day by day. The aim of this research was to preparation and characterization of biodegradable films supported with ZnOnanorods. In this study, sago starch based films were prepared and  plasticized with sorbitol/ glycerol by casting method. ZnOnanorod with 0, 1, 3and 5%(w/w)was added to the films before casting the films. Films were dried at controlled conditions. Physicochemical properties such as water absorption capacity (WAC), permeability to water vapor (WVP) and water solubility of the films were measured. Also, the effects of addition of nano particles were measured on the antimicrobial properties of the films by agar diffusion method. Results showed that by increasing concentration of ZnOnanorod, solubility in water, WAC, and WVP of the films significantly (p <0.05) decreased. Furthermore, the addition of zinc oxide nanorods showed antimicrobial properties against E. Coli. In summary sago starch films supported with ZnOnanorodscan were used as active packaging for agricultural products as well as food industry. پرونده مقاله -
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99 - Zinc Oxide Nanoparticles Absorption Rate in the Heart Tissue of Female Mice
Ramona Kasra Kermanshahi Vida Hojati Abdolhossein Shiravi   Nanotechnology researchers have identified a wide range of nanoparticle applications that may have an important role in medicine and treatment of diseases. Due to lack of detailed documentation about the toxicology of zinc oxide (ZnO) nanoparticles, this study was چکیده کامل   Nanotechnology researchers have identified a wide range of nanoparticle applications that may have an important role in medicine and treatment of diseases. Due to lack of detailed documentation about the toxicology of zinc oxide (ZnO) nanoparticles, this study was aimed to evaluate the absorption of ZnO nanoparticles in hearts of female NMRI mice. Overall, 20 adult NMRI female mice were studied in experimental and control groups. ZnO nanoparticles with concentration of 100 and 300 mg/kg were administered in the drinking water for 28 days and the mice were dissected after 28 days. Then, the heart tissues were isolated and dissolved in acid and the amount of ZnO deposited into the heart tissue was measured by atomic absorption spectrophotometer. ZnO nanoparticles treatment groups were significantly influenced by the nanoparticles compared with the control group. The experimental group 1 and 2 had a significant increase in ZnO NPs absorption in heart tissue compared to the control group (P<0.01). Due to the physiological similarities between mice and humans, the results of this study can be applied in prevention of the cardiac damage during the consumption of ZnO NPs. پرونده مقاله -
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100 - The Influence of Zinc Oxide Nanoparticles on Blood Markers in Domestic Pigeons (Columba livia)
Mehran Arabi Hamid-Reza NaseriThe analysis of blood provides a minimally invasive way to gain an insight into the health status of an organism. Organisms that have become closely associated to human housing are at greatest risk of being affected by anthropogenic pollutants. The purpose of this study چکیده کاملThe analysis of blood provides a minimally invasive way to gain an insight into the health status of an organism. Organisms that have become closely associated to human housing are at greatest risk of being affected by anthropogenic pollutants. The purpose of this study was to determine the alterations in blood markers of domestic pigeon (Columba livia) after oral administration of zinc oxide nanoparticles (n-ZnO). The birds were acclimatized to standard conditions with a photoperiod of 12:12 hr at 20±2ºC for 14 days. Birds were randomly assigned to one control and three experimental groups (in triplicate). The experimental groups orally received 30, 50, and 75 mg kg-1 b.w. of n-ZnO (1 ml/bird, daily) through oral gavage for 7 and 14 consecutive days. The oxidative stress (OS) biomarkers namely LPO/MDA level and CAT activity in the blood plasma samples with the activity of LDH were increased in a concentration-dependent manner. Meanwhile, total antioxidant capacity (TAC) of blood plasma and blood δ-ALAD activity were found to be lowered. Collectively, n-ZnO could affect the blood markers of pigeons, where oxidative damages may be the potential mechanism underlying this intoxication. پرونده مقاله -
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101 - Adsorption and Removal of Pollutants (dyes) from Wastewater Using Different Types of Low-cost Adsorbents: A review
Ahmed B. Mahdi Aseel M. Aljeboree Ayad F. AlkaimDischarge of dye-containing wastewater from various industries like textile, leather, paint, cosmetics etc. industries contributes to large amounts of pollution, leading to serious environmental problems such as quality deterioration of fresh water and endangering ecosy چکیده کاملDischarge of dye-containing wastewater from various industries like textile, leather, paint, cosmetics etc. industries contributes to large amounts of pollution, leading to serious environmental problems such as quality deterioration of fresh water and endangering ecosystems' health. One of the conventional anti-fungal agent in aquaculture which should be eliminated from wastewaters prior to releasing it into natural water resources. Tremendous volumes of colored wastewater are generated in textile, leather, paint, cosmetics etc. industries, causing eternal damage to the water resources. Wastewaters released from dye production and application industries are responsible for water pollution. Untreated disposal of the colored water into receiving water body causes damage to aquatic life and human bodies. Due to the high toxicity of dyes at low concentrations, they must be treated before being discharged into the receiving body of water. Therefore, environmental legislation has imposed severe limits on the discharged effluents' concentrations from dyestuff manufacturing and textile industries. پرونده مقاله -
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102 - پوشش نانو سیمهای اکسید روی بر روی الکترود آرایه های درهمتنیده طلا و بررسی عملکرد نانو حسگر گازهای الکلی
حمید غیور امین نکوبین امیرعباس نوربخشالکترود آرایههای درهمتنیده با استفاده از نانولیتوگرافی طلا بر روی بستر آلومینایی با روش PVD ساخته شد.از نانو میله اکسید روی به عنوان ماده حسگر استفاده شده که به روش هیدروترمال بر روی بذر لایه ای از اکسید روی سنتز شد. نانومیلههای سنتز شده با استفاده از تفرق پرتو ایکس چکیده کاملالکترود آرایههای درهمتنیده با استفاده از نانولیتوگرافی طلا بر روی بستر آلومینایی با روش PVD ساخته شد.از نانو میله اکسید روی به عنوان ماده حسگر استفاده شده که به روش هیدروترمال بر روی بذر لایه ای از اکسید روی سنتز شد. نانومیلههای سنتز شده با استفاده از تفرق پرتو ایکس(XRD)، میکروسکوپ الکترونی عبوری با تفکیک بالا(HR-TEM) ، میکروسکوپ الکترونی روبشی (SEM) و میکروسکوپ نیروی اتمی (AFM)مشخصه یابی گردید. عملکرد حسگری برای چهار گاز الکلی بررسی شد.به منظور بهینه کردن شرایط حسگری حساسیت و پاسخ نانومیله های اکسید روی در گستره دمایی 50 تا 300 درجه سانتیگراد بررسی شد. دمای کاری 47 درجه ساتیگراد به عنوان دمای بهینه انتخاب گردید و متغیرهای مهمی همچون حساسیت حسگر،زمان پاسخ دهی و زمان بازیابی برای چهار گاز در دمای ثابت و برای غلظتهای مختلف به دست آمد. نتایج حاصل نشان داد که با استفاده از نانومیله های همراستای اکسید روی؛ گازهای الکلی در دمای پایین با حساسیت بالا قابل تشخیص هستند. پرونده مقاله -
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103 - اثرpH بر خواص جذبی نانو ذرات اکسید روی-اکسید کادمیوم برای حذف متیل بلو و متیل اورانژ
الهه خلیلی فرد سید علی حسن زاده تبریزی مجتبی نصراصفهانینانو کامپوزیت ZnO-CdO با استفاده از روش میکروامولسیون آب در روغن سنتز شد. نسبت وزنی اکسید روی و کادمیم و دمای کلسیناسیون بر روی مورفولوژی، تشکیل فاز، تبدیلات فازی، اندازه کریستال هاوذرات و همچنین سطح ویژه نانو کامپوزیت ZnO-CdO تحقیق شد. محصولات سنتز شده توسط آنالیزهای X چکیده کاملنانو کامپوزیت ZnO-CdO با استفاده از روش میکروامولسیون آب در روغن سنتز شد. نسبت وزنی اکسید روی و کادمیم و دمای کلسیناسیون بر روی مورفولوژی، تشکیل فاز، تبدیلات فازی، اندازه کریستال هاوذرات و همچنین سطح ویژه نانو کامپوزیت ZnO-CdO تحقیق شد. محصولات سنتز شده توسط آنالیزهای XRD، BET، SEM، TEM و مورد بررسی قرار گرفت. نتایج پراش اشعه ایکس نشان داد که نانو کامپوزیت ZnO-CdO با کریستالهای نانومتری شکل گرفته است، ذرات نانو کامپوزیت روی-کادمیم سنتز شده در دمای˚C400 به دلیل سطح ویژه بالاتر بهترین خواص جذب و تجزیه متیل بلو و متیل اورانژ اسیدی را از خود نشان دادند. پرونده مقاله -
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104 - بررسی تاثیر افزودن نانو ذرات TiO2 بر روی هدایت الکتریکی نانو کامپوزیت RGO-ZnO
نجمه لطفیان امیرعباس نوربخش پریسا مشایخی سارا عباسپور سید مهدی میرهادی سعید جبارزارعپژوهش حاضر در ارتباط با بررسی هدایت الکتریکی نانو کامپوزیت RGO-ZnO-TiO2 در مقایسه با نانو کامپوزیت RGO_ZnO می باشد. در راستای انجام این پژوهش ابتدا گرافن اکساید با استفاده از روش هامر اصلاح شده سنتز و جهت تبدیل به گرافن اکساید احیاشده (RGO) تحت نور UV و دما قرار گرفت.سن چکیده کاملپژوهش حاضر در ارتباط با بررسی هدایت الکتریکی نانو کامپوزیت RGO-ZnO-TiO2 در مقایسه با نانو کامپوزیت RGO_ZnO می باشد. در راستای انجام این پژوهش ابتدا گرافن اکساید با استفاده از روش هامر اصلاح شده سنتز و جهت تبدیل به گرافن اکساید احیاشده (RGO) تحت نور UV و دما قرار گرفت.سنتز نانو ذرات TiO2 و ZnO توسط روش سل ژل انجام شد. جهت مشخصه یابی نانو ذرات سنتز شده،این نانو ذرات تحت آنالیز فازی XRD،DRSUV و FTIR قرار گرفتند و سنتز این نانو ذرات به خوبی اثبات گردید. جهت آماده سازی نمونه ها با استفاده از روش غوطه وری،نانو ذراتRGO ، ZnO وTiO2 به ترتیب بر روی شیشه FTO پوشش داده شدند و میزان باند گپ توسط روش تاک پلات و هدایت الکتریکی با استفاده از طیف سنجی امپدانس الکتروشیمیایی محاسبه ودو نمونهRGO-ZnO با RGO-ZnO-TiO2 مقایسه گردید. نتایج حاصل از مقایسه این دو نمونه نشان داد افزودن نانو ذرات TiO2به نانو کامپوزیت RGO-ZnO باعث کاهش باند گپ از 22/3 به 11/3 و افزایش مقاومت از 104*8/2 اهم به104 *76/5 اهم می گردد.با بررسی سطوح انرژی نانو ذرات ZnO,RGO,TiO2 ، علت این افزایش مقاومت به بالاتربودن سطح انرژی ZnO نسبت به TiO2 و عدم توانایی الکترون در غلبه بر این سدپتانسیل در عدم حضور نور UV نسبت داده شده و قرار دادن این نمونه تحت نور UV و کاهش شدید مقاومت تائیدی بر این مکانیزم می باشد. پرونده مقاله -
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105 - سنتز و بررسی خواص فوتوکاتالیستی نانو ذرات ZnO در اثر افزودن ZnWO4
سیدعلی حسن زاده مهدی امساکی علی صفارتلوریدر این پژوهش فعالیت فوتوکاتالیستی ZnO و نانوکامپوزیت حاصل از ترکیب آن با ZnWO4 مورد بررسی قرار گرفت. همچنین تأثیر افزودن ZnWO4 به نانو ذرات ZnO بر روی فعالیت فوتوکاتالیستی نانوکامپوزیت ZnO-ZnWO4 مورد مطالعه قرار گرفت. از روش میکروامولسیون آب در روغن به منظور سنتز نانو ذ چکیده کاملدر این پژوهش فعالیت فوتوکاتالیستی ZnO و نانوکامپوزیت حاصل از ترکیب آن با ZnWO4 مورد بررسی قرار گرفت. همچنین تأثیر افزودن ZnWO4 به نانو ذرات ZnO بر روی فعالیت فوتوکاتالیستی نانوکامپوزیت ZnO-ZnWO4 مورد مطالعه قرار گرفت. از روش میکروامولسیون آب در روغن به منظور سنتز نانو ذرات استفاده شد و درصدهای متفاوت استوکیومتری از این نانوکامپوزیت جهت بررسی خواص فوتوکاتالیستی سنتز شد. برای مشخصهیابی نانو ذرات، از آنالیزهای پراش پرتو ایکس (XRD)، میکروسکوپ الکترونی روبشی گسیل میدانی (FE-SEM)، میکروسکوپ الکترونی عبوری (TEM)، و طیفسنجی جذبی مرئی و فرابنفش (UV-Vis) استفاده شد. نتایج پراش اشعه ایکس نشان داد که نانوکامپوزیت ZnO-ZnWO4 با کریستالهای نانومتری شکل گرفته است و همچنین نتایج به دست آمده از TEM نشان دهنده توزیع اندازه ذرات در محدوده 40 تا 60 نانومتر است. نتایج نشان میدهد که راندمان تخریب فتوکاتالیستی رنگ متیلن بلو توسط نانوذرات ZnO در اثر افزوده شدن ZnWO4، افزایش چشمگیری داشته و بالاترین راندمان تخریب مربوط به نانوکامپوزیت ZnO-30%ZnWO4 با 57/96% است. پرونده مقاله -
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106 - سنتز نانوذرات اکسید روی دوپ شده توسط نقره به روش سل-ژل پکینی و مشخصهیابی و بررسی خواص فوتوکاتالیستی انها
حمیدرضا یوسفی بابک هاشمیاکسید روی (ZnO)نیمه هادی اکسیدی است که خواص فوتوکاتالیستی داشته و قابلیت تجزیه مواد آلی و تصفیه پساب های صنعتی را دارا می باشد. در این تحقیق نانوذرات اکسیدروی دوپ شده با درصدهای متفاوت نقره (Ag) به روش سل-ژل پکینی برای بررسی خواص فوتوکاتالیستی سنتز گردید. نانو ذرات به د چکیده کاملاکسید روی (ZnO)نیمه هادی اکسیدی است که خواص فوتوکاتالیستی داشته و قابلیت تجزیه مواد آلی و تصفیه پساب های صنعتی را دارا می باشد. در این تحقیق نانوذرات اکسیدروی دوپ شده با درصدهای متفاوت نقره (Ag) به روش سل-ژل پکینی برای بررسی خواص فوتوکاتالیستی سنتز گردید. نانو ذرات به دلیل داشتن نسبت سطح به حجم بالا می توانند خواص فوتوکاتالیستی بهتری از خود نشان دهند. همچنین افزودن فلزات نجیب به نیمه هادی می تواند مانع از باز ترکیبی جفت الکترون –حفره گردد. نمونه های سنتز شده حاوی 0/6، 1/8، 3/1 و 6/2 درصد وزنی نقره بودند. نمونه های بدست امده توسط طیف سنج UV-Vis، پراش اشعه X (XRD)، میکروسکوپ الکترونی روبشی (SEM)، میکروسکوپ گسیل میدانی (FESEM)، و طیف سنجی فوتولومینسانس(PL) مشخصه یابی گردیدند. در نهایت از نمونه های سنتز شده نسبت به زمان تست فوتوکاتالیستی در برابر متیلن آبی به انجام شد. با توجه به نتایج مشاهده گردید با دوپ نمودن نقره اندازه ذرات اکسید روی کاهش می یابد همچنین با افزودن نقره به نانوذرات ZnO تا حدود 1/8 درصد وزنی کاهش محسوسی در شدت فوتولومینسانس نمونه ها در محدوده فرابنفش ایجاد شده که نشان دهنده کاهش نرخ بازترکیبی الکترون-حفره و به دنبال ان افزایش نرخ فوتوکاتالیستی نمونه ها می باشد. تکرارپذیر بودن خصلت رنگبری فوتوکاتالیست سنتز شده بوسیله تکرار سه سیکل فوتوکاتالیستی بر روی نمونه دوپ شده با 1/8 درصد وزنی نقره انجام شد، مشاهده گردید که راندمان کاتالیست سنتز شده کاهش چشمگیری نداشته و این نشان دهنده پایداری فوتو کاتالیست سنتز شده است. پرونده مقاله -
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107 - ارزیابی خواص فتوکاتالیزوری و ضد باکتری نانوکامپوزیت ZnO-CuO تولید شده به روش سل- ژل
سیده زهرا انوری محمد حاجب محمود فاضل نجف آبادیدر این تحقیق نانو ذرات CuO، ZnO و نانوکامپوزیت ZnO-CuO با روش سل ژل سنتز شد. ویژگیهای محصولات سنتز شده با استفاده از آزمونهای XRD، DRS-UV و FESEM ارزیابی شد. نتایج تجزیه و تحلیل XRD نشان داد که نانو ذرات CuO، ZnO و کامپوزیت ZnO-CuO کریستالی بوده و آمورف نیست. نتایج تج چکیده کاملدر این تحقیق نانو ذرات CuO، ZnO و نانوکامپوزیت ZnO-CuO با روش سل ژل سنتز شد. ویژگیهای محصولات سنتز شده با استفاده از آزمونهای XRD، DRS-UV و FESEM ارزیابی شد. نتایج تجزیه و تحلیل XRD نشان داد که نانو ذرات CuO، ZnO و کامپوزیت ZnO-CuO کریستالی بوده و آمورف نیست. نتایج تجزیه و تحلیل DRS-UV نشان داد که به ترتیب CuO، ZnO و نانوکامپوزیت ZnO-CuO دارای متوسط انرژی شکاف باند 27/1 و 21/3 و 43/2 الکترون ولت هستند. محاسبات نشان داد ترکیبات CuO و ZnO و کامپوزیت ZnO–CuO در اثر تابش نور میتواند به ترتیب 40، 10 و 68% از آلایندهی رنگی رودامین B را تخریب نماید؛ بنابراین کامپوزیت نمودن ZnO با CuO سبب افزایش فعالیت فتوکاتالیزوری محصولات شد. همچنین مکانیسم فعالیت فتوکاتالیزوری محصولات سنتز شده و نقش اکسید مس در افزایش بازه فرآیند فتوکاتالیزوری مورد بحث قرار گرفته است. ارزیابی خواص ضد باکتری نشان داد نانو کامپوزیت ZnO-CuO دارای توانایی ضد باکتریایی علیه استافیلوکوکوس آرئوس بهعنوان باکتری گرم مثبت و اشریشیاکلی بهعنوان باکتری گرم منفی است. پرونده مقاله -
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108 - تاثیر افزودن SiC بر خواص برقگیرهای نانوکامپوزیت بر پایه ی ZnO زینتر شده در کوره ی میکروویو
مانی آزادمند علی نعمتی کاوه ارزانی نسترن ریاحی نوری تورج عبادزادهدر تحقیق حاضر برای نخستین بار به بررسی اثر افزودن درصدهای مختلف SiC بر ریز ساختار و خواص الکنریکی برقگیرهای بر پایه ی ZnO زینتر شده در کوره میکروویو پرداخته شد. به این منظور فرمول کلی مطابق فرمول شیمیایی برقگیرهای بر پایه ی ZnO متداول انتخاب و SiC بین 0 تا 10 درصد وزنی چکیده کاملدر تحقیق حاضر برای نخستین بار به بررسی اثر افزودن درصدهای مختلف SiC بر ریز ساختار و خواص الکنریکی برقگیرهای بر پایه ی ZnO زینتر شده در کوره میکروویو پرداخته شد. به این منظور فرمول کلی مطابق فرمول شیمیایی برقگیرهای بر پایه ی ZnO متداول انتخاب و SiC بین 0 تا 10 درصد وزنی جایگزین ZnO در فرمول گردید. جهت بررسی ریزساختار نمونه ها از تصاویر میکروسکوپ الکترونی SEM، و برای بررسی توزیع عناصر از Map Scan استفاده شد. شناسایی فازها با استفاده از پراش اشعه X انجام شد. همچنین خواص برقگیری نمونه ها توسط دستگاه آزمایش I-V اندازه گیری شد. مشاهده شد که افزودن SiC به ترکیب باعث جلوگیری از رشد دانه های ZnO حین زینترینگ می گردد. همچنین با افزودن SiC به ترکیب با ایجاد فاز ویلمیت خواص برقگیری بهبود چشمگیری یافته و در ادامه با افزایش بیشتر درصد SiC، درصد تخلخل افزایش و در نتیجه خواص تقلیل یافت. بهترین خواص برقگیری مربوط به نمونه های ساخته شده حاوی 4 و 6 درصد SiC بود. در این پژوهش به ولتاژ آستانه (V/cm) 10300 VT=، ضریب غیر خطی 65 =α و جریان نشتی (mA)03/0IL= دست یافته شد. پرونده مقاله -
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109 - بررسی تأثیر نانوذره Fe2ZnO4بر سلولهای خونی در موشهای صحرایی نر نژاد ویستار
اسما گرامی محبوبه سترکی زهرا هوشمندیبه دلیل افزایش روزافزون تولید و مصرف نانوذرات، مطالعاتی گستردهای نیاز است تا اثرات احتمالی منفی و سمیت آنها تعیین گردد. هدف مطالعه حاضر بررسی تأثیر نانوذره Fe2ZnO4 بر شمارش سلولهای خونی و درصد هماتوکریت در موشهای صحرایی نژاد ویستار بود.در مطالعه تجربی حاضر، 24 موش چکیده کاملبه دلیل افزایش روزافزون تولید و مصرف نانوذرات، مطالعاتی گستردهای نیاز است تا اثرات احتمالی منفی و سمیت آنها تعیین گردد. هدف مطالعه حاضر بررسی تأثیر نانوذره Fe2ZnO4 بر شمارش سلولهای خونی و درصد هماتوکریت در موشهای صحرایی نژاد ویستار بود.در مطالعه تجربی حاضر، 24 موش صحرایی نر نژادویستاربا میانگین وزنی 43 ± 234 به صورت تصادفی به گروههای 8 تایی تقسیم شدند. گروه اول 5/0 میلیلیتر سرم فیزیولوژی و گروههای دوم و سوم 5/0 میلیلیتر آب مقطر حاوی نانوذره Fe2ZnO4 در غلظتهای 100 و 200 ppm به مدت 7 روز از طریق تزریق داخل صفاقی دریافت کردند.شمارش گلبولهای قرمز، شمارش گلبولهای سفید، شمارش پلاکتها و درصد هماتوکریت در روزهای 2، 7 و 14 پس از مواجه صورت گرفت. نانوذره Fe2ZnO4سبب کاهش معنیدار گلبولهای سفید و افزایش معنیدار گلبولهای قرمز شد. درصد نوتروفیلها و لنفوسیتها در مواجه با نانوذرات افزایش یافت که نشان دهنده پاسخ سیستم ایمنی ذاتی در برابر نانوذرات میباشد. نانوذره Fe2ZnO4 سبب کاهش معنیدار میزان پلاکت خون موشهای صحرایی گردید و غلظت ppm 200 نانوذره کاهش بیشتری در مقایسه با غلظت 100ppm ایجاد کرد (05/0p پرونده مقاله
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