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دسترسی آزاد مقاله
1 - حذف آلاینده فنل از محیط آبی با استفاده از نانوکامپوزیت TiO2/SBA-15 با بکارگیری روش پاسخ سطحی
سمیرا خدابخش لعبت تقوی ابراهیم علایی لیلا سمیعیزمینه و هدف: ترکیبات فنلی یکی از مهم ترین مواد آلاینده هستند که موجب سمی شدن منابع آب می گردند. حضور فنل و مشتقات آن در آب و فاضلاب به دلیل سمیت و تهدیدی که برای زندگی انسان، حیوان و محیط ایجاد می کند یک نگرانی عمده محسوب می شود. به هر- حال شناخت و ردیابی این آلاینده ها چکیده کاملزمینه و هدف: ترکیبات فنلی یکی از مهم ترین مواد آلاینده هستند که موجب سمی شدن منابع آب می گردند. حضور فنل و مشتقات آن در آب و فاضلاب به دلیل سمیت و تهدیدی که برای زندگی انسان، حیوان و محیط ایجاد می کند یک نگرانی عمده محسوب می شود. به هر- حال شناخت و ردیابی این آلاینده ها و همچنین شناخت راه های کنترل و حذف آن ها امری بسیار مهم برای حفظ محیط زیست، تصفیه انواع فاضلاب و تأمین آب آشامیدنی سالم و بهداشتی می باشد. لذا این تحقیق با هدف اصلی حذف آلاینده فنل از محیط آبی با غلظت اولیه بالا(mg/l100) توسط فرایند هتروژن فوتوکاتالیست در راکتور با پوشش شیشه ای پیرکس با بستر شبه مایع انجام یافت.روش بررسی: ابتدا آنالیز پاسخ سطحی برای نانوکاتالیست TiO2 به همراه هیدروژن پراکسید و اشعه UV 250 وات، برای یافتن شرایط بهینه حذف فنل از محیط آبی به روش هتروژن فوتوکاتالیست انجام شد.سپس جاذب SBA-15 که به دلیل ساختار متخلخل قابلیت زیادی در حذف آلاینده فنل در میان سایر جاذب ها دارد و سپس نانوکامپوزیت TiO2/SBA-15 سنتز شد. سپس ویژگی های ساختاری و فیزیکی نانوکامپوزیت توسط آنالیزهایTEM ، FESEM، BET ، XRD شناسایی شد.یافته ها:نتایج بیان گر کارایی حذف 96% فنل با غلظت mg/l100 در مدت زمان 420 دقیقه بود.استفاده از روش پاسخ سطحی برای تعیین شرایط بهینه یکی از روش های مؤثر برای دست یابی به هدف مورد نظر در این تحقیق بود.بحث و نتیجه گیری: با توجه به نتایج، ملاحظه می شود که مواد مزو متخلخل پریودیک حاوی TiO2 در مقایسه با TiO2 پشتیبانی نشده راندمان بالایی در تخریب فوتوکاتالیزوری آلاینده های آبی دارد. پرونده مقاله -
دسترسی آزاد مقاله
2 - Application of Magnetic Nano Adsorbent Fe2O3 for Removal of Hazardous Ponceau-S Dye from Aqueous Solution
B. N. Patil D. S. Shirsath Y. V. Marathe V. S. ShrivastavaThe photodegradation of Ponceau-S dye was investigated using UV radiation in presence of nanosized Fe2 O3 .Removal efficiency of Ponceau-S was sensitive to the operational parameters such as dye concentration, catalyst dose, pH, contact time, TOC and COD. The photocatal چکیده کاملThe photodegradation of Ponceau-S dye was investigated using UV radiation in presence of nanosized Fe2 O3 .Removal efficiency of Ponceau-S was sensitive to the operational parameters such as dye concentration, catalyst dose, pH, contact time, TOC and COD. The photocatalytic treatment of red colored Ponceau-S dye by magnetic nano semiconductor (Fe2 O3 )is an effective, economic and faster mode. The kinetics and isotherm studies were carried out. A simple kinetics model was proposed which confirmed pseudo second order reaction. Langmuir isotherm fitted this study. The optimum conditions for the degradation of the dye were initial concentration 50 mgL-1, pH 8, contact time 20 minutes and catalyst dose 5 gL-1 of Fe2 O3 .The semiconductor photocatalyst was also carried out for SEM and XRD analysis which confirms the utilized semiconductor was nanosized. پرونده مقاله -
دسترسی آزاد مقاله
3 - Contributing factors on the removal of Azo-dyes from industrial wastewater: A comparison of the efficiency of sonocataysis and photocatalysis process
Azam Pirkarami Leila Fereidooni Kambiz TahvildariThe influence of the number of operating parameters on photocatalytic and sonocatalytic Acid Red 88 degradation from an aqueous solution was investigated in this paper. The experimental results indicated that the sonocatalytic process with Ni-TiO2 was far more effective چکیده کاملThe influence of the number of operating parameters on photocatalytic and sonocatalytic Acid Red 88 degradation from an aqueous solution was investigated in this paper. The experimental results indicated that the sonocatalytic process with Ni-TiO2 was far more effective for the degradation of high concentration azo dyes, regardless of the process condition. In order to achieve a larger surface area of the catalyst, Ni-TiO2 was suspended in the aqueous solution. The optimum experimental conditions obtained as catalyst dosage of 0.6mg L-1, pH of 7 and dye concentration of 30 mg L-1. The COD value of the solution after photodegradation showed a significant decrease to 59 mg L-1 from 1573 mg L-1 while this value decreased to 34 mg L-1 after sonocatalytic degradation. The catalyst performance was evaluated by SEM and XRD techniques. Dye removal efficiency of 88% was obtained by sonocatalysis process with a dye concentration of 300 mg L-1 and within a pH range of 2-11. However, the efficiency was only 28% after photocatalytic degradation with the same dye concentration and within a more limited pH range of 3-9. Therefore, a specific method was proposed in this article for azo dye degradation. پرونده مقاله -
دسترسی آزاد مقاله
4 - مروری بر خواص الکترونیکی و ساختاری فتوکاتالیزگرهای تیتانیوم دی اکسید برای حذف آلاینده های زیست محیطی پساب ها
عبدالحمید دهقانی اعظم مؤذنی بیستگانی میلاد قزلسفلو سهیل دهقانی سیاهکی حمید رضا مرادیامروزه، تصفیه آلاینده های زیست محیطی پساب ها(رنگ‌های نساجی و فاضلاب‌های ناشی از پساب های دارویی) به یکی از مسائل چالش برانگیز تبدیل شده‌است و روش‌های متعددی برای تصفیه این دسته از پساب ها از جمله روش‌های شیمیایی، فیزیکی و بیولوژیکی مورد استفاده قرار گرفته است که هر کدا چکیده کاملامروزه، تصفیه آلاینده های زیست محیطی پساب ها(رنگ‌های نساجی و فاضلاب‌های ناشی از پساب های دارویی) به یکی از مسائل چالش برانگیز تبدیل شده‌است و روش‌های متعددی برای تصفیه این دسته از پساب ها از جمله روش‌های شیمیایی، فیزیکی و بیولوژیکی مورد استفاده قرار گرفته است که هر کدام از این روش‌ها دارای مزایا و معایب خاص خود بوده است. در چند دهه اخیر، تیتانیوم دی اکسید به‌دلیل خواص شیمیایی و فیزیکی منحصر به‌فردش، شرایط مناسبی برای کاربردهای زیست محیطی ایجاد کرده‌است. اساس فرایند‌های فتوکاتالیزگری، مبتنی بر تولید گونه‌های بسیار فعال مانند رادیکال‌های هیدروکسیل می‌باشد که این گونه‌های فعال، گستره وسیعی از آلاینده‌های آلی را به سرعت اکسید می‌کنند. تیتانیوم دی اکسید به عنوان یک نیمه هادی به‌دلیل ارزان قیمت بودن، عدم سمیت، پایداری شیمیایی بالا، دردسترس بودن و بازده بالا به‌عنوان یک فتوکاتالیزگر کارآمد جهت اکسایش ترکیبات آلی، سمیت زدایی، احیا فلزات سمی، حذف موثر فلزات سنگین، تخریب باکتری‌ها و ویروس‌ها مورد استفاده قرار گرفته است. از آن‌جایی که تیتانیوم دی اکسید و بسیاری از نیمه هادی‌های دیگر دارای شکاف باند بزرگی هستند، استفاده از تصفیه فتوکاتالیزگری آب با استفاده از تیتانیوم دی اکسید به‌دلیل راندمان نسبتا پایین آن محدود شده‌است. به منظور بهبود راندمان فتوکاتالیزگری تیتانیوم دی اکسید برای تصفیه آب، و همچنین سایر کاربردهای فتوکاتالیزگری، تحقیقات زیادی برای گسترش پاسخ فتوکاتالیزگری تیتانیوم دی اکسید به محدوده مرئی انجام شده‌است. در این مقاله، به طور نظامند به معرفی تیتانیوم دی اکسید و بررسی خواص الکترونیکی و ساختاری آن پرداخته می شود. پرونده مقاله -
دسترسی آزاد مقاله
5 - Incorporation of Zinc Oxide Nanoparticles in RHA-MTW Zeolite and its Application for Degradation of Dye
afshin pourahmad Babak Sadeghi Babak Azari Masoud MokhtaryWhite rice husk ash (RHA), an agriculture waste, was used as a silica source for MTW zeolite synthesis. The RHA-MTW zeolite derived from RHA was prepared by hydrothermal method at 150 °C in the presence of tetraethylammonium hydroxide. ZnO nanoparticles (NPs) were grow چکیده کاملWhite rice husk ash (RHA), an agriculture waste, was used as a silica source for MTW zeolite synthesis. The RHA-MTW zeolite derived from RHA was prepared by hydrothermal method at 150 °C in the presence of tetraethylammonium hydroxide. ZnO nanoparticles (NPs) were grown in zeolite substrates using a solid state reaction. The synthesized nanocomposite (NC) was characterized by XRD, SEM, DRS and TEM and tested as photocatalytic degradation of methylene blue (MB) dye from aqueous solution under ultraviolet (UV) light. The BET results indicated that pore volume and surface area of ZnO/RHA-MTW NC was smaller than RHA-MTW zeolite. On the basis of the obtained experimental results, it was founded that zinc oxide NPs were encapsulated into channels of RHA-MTW zeolite. The SEM and TEM images of ZnO/RHA-MTW NC confirmed the formation of RHA-MTW particles with size diameter of 2.5 µm and locating of zinc oxide NPs in channels of zeolite with an average size of between 35 nm. The results showed MB degradation reached 85 % under UV light. The MB indicated maximum adsorption at pH=9. The photocatalytic activity of ZnO was enhanced in the presence of zeolite due to reduction of recombination rate of the electro-hole in ZnO semiconductor. پرونده مقاله -
دسترسی آزاد مقاله
6 - Incorporation of Zinc Oxide Nanoparticles in RHA-MTW Zeolite and its Application for Degradation of Dye
Babak Azari Afshin Pourahmad Babak Sadeghi Masoud MokhtaryWhite rice husk ash (RHA), an agricultural waste, was used as a silica source forMTW zeolite synthesis. The RHA-MTW zeolite derived from RHA was preparedby hydrothermal method at 150 °C in the presence of tetraethylammoniumhydroxide. ZnO nanoparticles (NPs) were gro چکیده کاملWhite rice husk ash (RHA), an agricultural waste, was used as a silica source forMTW zeolite synthesis. The RHA-MTW zeolite derived from RHA was preparedby hydrothermal method at 150 °C in the presence of tetraethylammoniumhydroxide. ZnO nanoparticles (NPs) were grown in zeolite substrates using asolid state reaction. The synthesized nanocomposite (NC) was characterized byXRD, SEM, DRS and TEM and tested as photocatalytic degradation of methyleneblue (MB) dye from aqueous solution under ultraviolet (UV) light. The BET resultsindicated that pore volume and surface area of ZnO/RHA-MTW NC was smallerthan RHA-MTW zeolite. On the basis of the obtained experimental results, it wasfound that zinc oxide NPs were encapsulated into the channels of RHA-MTWzeolite. The SEM and TEM images of ZnO/RHA-MTW NC confirmed the formationof RHA-MTW particles with size diameter of 2.5 μm and locating of zinc oxideNPs in channels of zeolite with an average size of between 35 nm. The resultsshowed MB degradation had reached 85 % under UV light. The MB indicatedmaximum adsorption at pH=9. The photocatalytic activity of ZnO was enhancedin the presence of zeolite due to reduction of recombination rate of the electroholein ZnO semiconductor.ARTICLE INF O پرونده مقاله -
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7 - Nano cotton-shape mesoporous (NCSM) modified by Fe3O4: Green, magnetic and reusable catalytic system for dechlorization of bromothymol blue (BTB)
Hamid AliyanFe3O4-containing cotton-like mesoporous silica system (Fe3O4@NCSM) was studied with regard to its performance towards the photodecolorization of bromothymol blue (BTB) aqueous solution. The surface properties of the functionalized catalyst were analyzed by a series of c چکیده کاملFe3O4-containing cotton-like mesoporous silica system (Fe3O4@NCSM) was studied with regard to its performance towards the photodecolorization of bromothymol blue (BTB) aqueous solution. The surface properties of the functionalized catalyst were analyzed by a series of characterization techniques like FTIR, XRD, BET, SEM and TEM. The N2 Adsorption–desorption analysis shows that the mesostructure of silica remains intact after Fe3O4 modifications, while the spectral technique shows the successful encapsulating of the neat Fe3O4 inside the porous silica support. The optimum values of the experimental parameters which affect the degradation efficiency were obtained as: 0.15 g L−1 of the photocatalyst, 25 ppm dye concentration and pH 5.6. پرونده مقاله -
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8 - Photo corrosion of titania nanotubes within water splitting reaction
Shahab Khameneh Asl Deniz UnarTitania nanotubes (TNT) prepared by anodization of Ti foils were used for water splitting in a standalone cell. The concentration polarization between the anode side (1M NaOH) and cathode side (0.5 M H2SO4) ensured that the water splitting reaction could take place with چکیده کاملTitania nanotubes (TNT) prepared by anodization of Ti foils were used for water splitting in a standalone cell. The concentration polarization between the anode side (1M NaOH) and cathode side (0.5 M H2SO4) ensured that the water splitting reaction could take place with no external bias and separate H2 and O2 evolution could be achieved. The destruction of TNT structures under 365 nm UV irradiation as well as the absence of the stoichiometry between the anodic and cathodic gas collectors indicates the limits of the stability of TNT structures under these conditions. پرونده مقاله -
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9 - Synthesis and photocatalytic activity of nanosized modified mesocellulous silica foams (MCFs) with PW12 and vanadium oxide
Leili Shabani Hamid AliyanA series of tungestophosphoric acid and vanadium oxide supported on Mesocellulous Silica Foams (MCFs) featuring a well-defined three-dimensional (3D) mesoporosity were studied with regard to their performance in the photocatalytic activity to degrade Oezine Y (OY). This چکیده کاملA series of tungestophosphoric acid and vanadium oxide supported on Mesocellulous Silica Foams (MCFs) featuring a well-defined three-dimensional (3D) mesoporosity were studied with regard to their performance in the photocatalytic activity to degrade Oezine Y (OY). This nanosized mesoporous catalyst (PW12@V-MCF) was characterized by FTIR, XRD, BET and TEM. XRD shows that the structure of MCF remains intact after PW12 modification, while spectral techniques show the successful grafting of the PW12 on the MCF cavities. PW12-MCF was used as a catalyst in the photodecolorization process of Oezine Y (OY) dye in aqueous solution under UV radiation. It was found that the catalyst exhibited significantly high catalytic stability, and the activity loss is negligible after three OY degradation cycles. پرونده مقاله -
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10 - Eco-friendly preparation and characterization of CuMn2O4 nanoparticles with the green capping agent and their photocatalytic and photovoltaic applications
Ali Sobhani-Nasab Mohammad Eghbali-Arani Seyed Mostafa Hosseinpour-Mashkani Farhad Ahmadi Mehdi Rahimi-Nasrabadi Vahid AmeriIn this study, copper manganese oxide (CuMn2O4) nanoparticles were successfully synthesized by a simple sol-gel technique in the presence of lactose as the green capping agent. The lactose concentration effect on the crystalline size and magnetic properties of final pro چکیده کاملIn this study, copper manganese oxide (CuMn2O4) nanoparticles were successfully synthesized by a simple sol-gel technique in the presence of lactose as the green capping agent. The lactose concentration effect on the crystalline size and magnetic properties of final products were systematically investigated. The structural, morphological, magnetic, and optical properties of as-obtained products were examined by techniques such as the Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscopy (FESEM), vibrating-sample magnetometer (VSM) and UV–Vis diffuse reflectance spectroscopy. SEM and VSM results show that lactose concentrations play an important role in the magnetic properties and morphology of CuMn2O4 nanoparticles. Degradation of type of dye (Rhodamine B = Rh B and Methyl orange = MO) under ultraviolet light was examined to assess the feasibility of using CuMn2O4 for photocatalytic activities. To demonstrate the possibility of developing an inexpensive solar cell, FTO/TiO2/CuMn2O4/Pt-FTO, the CuMn2O4 paste was put on the top of the TiO2 through the doctor blade technique. پرونده مقاله -
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11 - Nitrogen doped TiO2 for efficient visible light photocatalytic dye degradation
Jila Talat-Mehrabad Mohammad Partovi Farzad Arjomandi Rad Rana KhalilnezhadIn this study, Nitrogen doped TiO2 photocatalysts were prepared by the sol gel method and physicochemical properties were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM), photoluminescence, and energy dispersive X-ray spectroscopy (DRS) چکیده کاملIn this study, Nitrogen doped TiO2 photocatalysts were prepared by the sol gel method and physicochemical properties were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM), photoluminescence, and energy dispersive X-ray spectroscopy (DRS) techniques. The XRD data indicated that the nanoparticles had the same crystals structures as the pure TiO2. Photocatalytic properties of the nitrogen doped TiO2 nanocatalyst and pure TiO2 were compared for degradation of Blue 5 dye in visible light irradiation and the DRS results showed that the band gap of doped photocatalyst was smaller than that of the undoped TiO2 and there was a shift in the absorption band toward the visible light region. The Photocatalytic properties of the nitrogen doped TiO2 nanocatalyst wereemployed for degradation of crystal Blue 5 dye under visible light irradiation. The effects of pH, amount of photocatalysts,catalyst dosage, and dye concentration were also examined. The best results were reported for the concentration of 20 mg/L N-TiO2 nano-particles. Also results showed that the photodecomposition of N-TiO2 is complete at pH 11. Total organic carbon (TOC) analysis indicated 30 % mineralization of Blue 5 after 75 min irradiation. پرونده مقاله -
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12 - 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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13 - Photocatalytic degradation of malachite green dye using NiAl2O4 and Co doped NiAl2O4 nanophotocatalysts prepared by simple one pot wet chemical synthetic route
M. Arunkumar A. Samson NesarajNovel metal oxides have been studied worldwide due to their potential uses in ecological refinement, particularly to eliminate organic impurities present in water. In this work, we report the preparation of Ni1-xCoxAl2O4-δ (where x=0, 0.05, 0.10, 0.15 and 0.20) na چکیده کاملNovel metal oxides have been studied worldwide due to their potential uses in ecological refinement, particularly to eliminate organic impurities present in water. In this work, we report the preparation of Ni1-xCoxAl2O4-δ (where x=0, 0.05, 0.10, 0.15 and 0.20) nanoparticles by simple chemical precipitation route. The as-synthesized spinel particles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), particle size analysis, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), UV-Vis Spectroscopy (UV) and Photo Luminescence (PL) Spectroscopy techniques. The XRD results affirmed the development of the cubic structure in all the samples. FT-IR confirmed the presence of the M-O bond. Particle characteristics statistics showed the existence of particles in the range of 36-741 nm range. SEM analysis strengthened the presence of various sized grains (nano and micron) in the samples. EDX analysis affirmed the existence of an appropriate amount of elements (Ni, Al, Co and O) in all the samples. The band gap of Co doped NiAl2O4 was in between 2.8 – 3.0 eV, which was in line with the reported data. The PL spectra exhibited a strong peak at around 450 nm in the samples. From UV studies, the λmax was around 310 nm in all the prepared samples. The photoluminescent characteristics of the samples were confirmed by PL studies and their photoemission was found at 437 nm. Among the samples studied, the parent NiAl2O4 shows more efficiency in degrading the malachite green (MG) dye than other Co doped NiAl2O4 photocatalysts under the irradiation of visible light at the wavelength of 616nm at normal temperature. پرونده مقاله -
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14 - Optical, Morphological and Microstructural Investigation of TiO2 nanoparticles for Photocatalytic application
B. Manikandan K. R. Murali Rita JohnEnriched characteristics like porosity, stability and specific surface area assist TiO2 to find extensive applications in photocatalysis, dye sensitized solar cell, and sensors. TiO2 semiconductor was prepared using titanyl acetylacetonate and characterized by XRD, FTIR چکیده کاملEnriched characteristics like porosity, stability and specific surface area assist TiO2 to find extensive applications in photocatalysis, dye sensitized solar cell, and sensors. TiO2 semiconductor was prepared using titanyl acetylacetonate and characterized by XRD, FTIR, Raman, UV-Vis, FESEM, EDX, and DLS. XRD result confirmed the tetragonal structured anatase TiO2 semiconductor. Scherrer formula is used to calculate crystallite size and the obtained value is 6.81 nm. Microstrain, stress, energy density, and crystallite size are calculated using W-H model. The absorption peak of TiO2 is observed at 652.11 cm-1 from FTIR spectrum and authenticated the anatase TiO2 semiconductor. The UV absorption edge is identified at 365 nm and the bandgap is calculated from the Kubelka-Munk equation using Tauc plot. Raman spectrum show bands at 140,197, 395, 512, and 635 cm-1 and these peaks confirmed the presence of the anatase TiO2 stretching mode. FESEM micrographs exhibited agglomerated spherical morphology and the particle size was further analysed using DLS study. The elemental compositions were identified in the EDX analysis. The obtained spectrum showed 55.88 Wt% of O and 44.12 Wt% of Ti atoms. The prepared anatase TiO2 semiconductor indicated enhanced catalytic behaviour. The rate constants and half life time are related to crystallite size using mathematical relation. It is found that the degradation process varies with crystallite size. پرونده مقاله -
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15 - 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 -
دسترسی آزاد مقاله
16 - Synthesis of a thin film of CuO/MgO/PVC nanocomposites for Photocatalytic applications
Rouabeh Nouhad Roshan Nazir Yassine Djaballah AbQayoom Mir Imene Ameur Ouidad BeldjebliThis study investigates the effect of a combination of copper and magnesium oxide nanoparticles embedded in a Polyvinyl chloride (PVC) matrix on photocatalytic activity. A thin film of CuO/MgO/PVC nanocomposites (NCs) was synthesized using the sol-gel route. Different w چکیده کاملThis study investigates the effect of a combination of copper and magnesium oxide nanoparticles embedded in a Polyvinyl chloride (PVC) matrix on photocatalytic activity. A thin film of CuO/MgO/PVC nanocomposites (NCs) was synthesized using the sol-gel route. Different weight percentages of CuO/MgO nanocomposites (5% and 15%) incorporated in the PVC matrix were deposited on glass strips using the spin coating method. The characterization of these thin films were carried out by a series of analytical and spectroscopic tools including PXRD, AFM, UV-Vis, and FTIR spectra analysis. The bandgap energy of MgO/PVC significantly reduced from 4.00 eV to 3.77 eV in 15% CuO/MgO/PVC NCs. This study also demonstrates the high ability of CuO/MgO/PVC thin films towards the photodegradation of methylene blue (MB) dye with a proposed reaction mechanism. A comparative analysis for the photodegradation of MB dye revealed superior photocatalysis by 15%with a rate constant of 5.20 × 10-3 min-1 showing about 44% efficiency. The credit goes to the decrease in the band gap, enhancement in charge separation, and increase in surface area of thin film CuO/MgO/PVC NCs. پرونده مقاله -
دسترسی آزاد مقاله
17 - Effect of surfactant on structural and optical properties of V2O5 nanocrystals as a potential catalyst for photodegradation
F. Sanakousar C. Vidyasagar S. Chigari Swapna Victor Jiménez-Pérez C. Viswanath K. Prakash M. SridharaAn anionic, cationic, and non-ionic surfactant-assisted wet chemical method was used to synthesize vanadium pentoxide (V2O5) nanocrystals. XRD, FESEM, EDX, FTIR, UV-Vis, and PL techniques were used to characterize the V2O5 nanocrystals. The formation of V2O5 nanocrystal چکیده کاملAn anionic, cationic, and non-ionic surfactant-assisted wet chemical method was used to synthesize vanadium pentoxide (V2O5) nanocrystals. XRD, FESEM, EDX, FTIR, UV-Vis, and PL techniques were used to characterize the V2O5 nanocrystals. The formation of V2O5 nanocrystals is confirmed by the experimental results. The addition of surfactants had a significant effect on the morphology, crystallinity, and optoelectronic characteristics of the prepared photocatalysts, as per the detailed characterization and analysis of the pertaining light-matter interactions. Additionally, the Scherrer and William-Hall plot methods were used to determine the crystallite sizes from the broadening of the XRD peak. Surfactant addition caused the sample bandgap to broaden, resulting in the blue shift in the distinctive absorption peak of V2O5 nanocrystals. To effectively separate the charge carriers during photocatalysis, the most effective photocatalyst (pure V2O5) material showed small crystallite size and short migration routes for the charge carriers which is confirmed by XRD and PL analysis. Pure V2O5 nanocrystals showed excellent yields in the photocatalytic degradation of Methylene Blue (MB) dye when exposed to sunlight compared to surfactant-assisted V2O5. The V2O5 catalyst’s photostability and reusability were also assessed; after four cycles of testing, the percentage degradation of MB was 94.75%. As per the scavenger experiment, photo-generated holes (h+) and superoxide radical’s anions (O2—‾.) are the major species responsible for the degradation of MB dye. There is a suggested mechanism for the higher degradation efficiency of V2O5 at neutral pH when exposed to sunlight. Pure V2O5 is a promising and effective photo-catalyst for the photocatalytic degradation of MB dye due to its extremely high performance. پرونده مقاله -
دسترسی آزاد مقاله
18 - 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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