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حرية الوصول المقاله
1 - Antioxidant Properties of Ajwain using Square wave, Cyclic voltammetry methods and DPPH method
Zahra khoramian Mohammad Hadi Givianrad Hessam Sepasi TehraniAjwain is one of the medicinal plants, which the highest composition is thymol, as a strong antioxidant respect to the obtained chromatograms of GC/MS. The antioxidant activity of the Ajwain is measured by square wave voltammetry method and cyclic voltammetry method and أکثرAjwain is one of the medicinal plants, which the highest composition is thymol, as a strong antioxidant respect to the obtained chromatograms of GC/MS. The antioxidant activity of the Ajwain is measured by square wave voltammetry method and cyclic voltammetry method and 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) method in at the specific concentrations of 1%, 1.5%, 2% and 2.5% and constant pH. The results of the present study indicated that the antioxidant activity of Ajwain obtained from cyclic voltammetry and square wave is almost equal to the results of the DPPH method, which can be used to measure the antioxidant activity. Compared to DPPH method, electrochemical method involves a number of advantages such as simplicity, cheap operating costs, fastness, low amount of solvent, and no need for chemical reagents. Furthermore, based on the results obtained, the square wave method includes a higher sensitivity and accuracy than cyclic voltammetry method and DPPH method. تفاصيل المقالة -
حرية الوصول المقاله
2 - Efficient photocatalytic desulfurization of thiophene under visible light irradiation over flower-like AgBiS2 photocatalyst
Mehdi Mousavi-Kamazani Reza Rahmatolahzadeh Hassan NajafianHere, we report the production of hierarchical flower-like AgBiS2 nanostructures by an amino acid-modified polyol route. This work indicates that by changing the polyol process conditions including kind of capping agent, reaction time and reflux temperature, the sheet-l أکثرHere, we report the production of hierarchical flower-like AgBiS2 nanostructures by an amino acid-modified polyol route. This work indicates that by changing the polyol process conditions including kind of capping agent, reaction time and reflux temperature, the sheet-like, cone-like, sphere-like and flower-like morphologies of AgBiS2 micro/nanostructures can be prepared. The phase, elemental composition, morphology and optical characteristics of as-prepared AgBiS2 nanostructures were analyzed by UV–Vis, FESEM, XRD, and EDS techniques. After characterization of the products, the AgBiS2 nanostructures were employed as novel photocatalysts for oxidative desulfurization of thiophene/n-octane solution as model fuel under visible light illumination. Results demonstrate that hierarchical flower-like AgBiS2 photocatalyst with desirable band gap energy (2.44 eV) has high photocatalytic desulfurization performance of about 89% after 2 h of visible light irradiation. As well as, the effects of morphology, photocatalyst dosage and reusability of the AgBiS2 nanostructures on the photocatalytic performance were evaluated. The excellent photocatalytic activity of AgBiS2 photocatalyst can be attributed to the strong visible light absorption, high separation rate of electron–hole pairs, special hierarchical structures and suitable band gap energy. Moreover, a reliable photo-oxidation desulfurization mechanism was discussed according to the active species trapping experiments, which revealed the photo-generated h+ and •O2− radicals were the main active species in the photocatalytic desulfurization process. تفاصيل المقالة -
حرية الوصول المقاله
3 - Fabrication of Bi14W2O27/Bi2WO6 photocatalyst for improved desulfurization of thiophene under simulated sunlight irradiation
Mohammad Ebadi Majid Asri Farshad BeshkarIn this work, novel Bi14W2O27/Bi2WO6 nanocomposite was prepared by a modified Pechini sol-gel approach. The effect of the gelling agent, chelating agent and mole ratio of chelating agent to total metals was controlled to produce ultrafine Bi14W2O27/Bi2WO6 nanoparticles. أکثرIn this work, novel Bi14W2O27/Bi2WO6 nanocomposite was prepared by a modified Pechini sol-gel approach. The effect of the gelling agent, chelating agent and mole ratio of chelating agent to total metals was controlled to produce ultrafine Bi14W2O27/Bi2WO6 nanoparticles. The as-prepared Bi14W2O27/Bi2WO6 nanocomposite was characterized by XRD, FESEM, FT-IR, EDS and UV–Vis analysis. The Bi14W2O27/Bi2WO6 nanostructures exhibited excellent photocatalytic desulfurization of thiophene (~90%) after 120 min of simulated sunlight irradiation. The high-efficiency photocatalytic desulfurization of the as-prepared Bi14W2O27/Bi2WO6 can be attributed to the improved visible-light absorption, ultrafine nanoparticles, and high separation and low recombination rates of charge carriers. In addition, a reliable photocatalytic desulfurization mechanism was explained using radical trapping experiment, which indicated that the photogenerated •O2− and •OH species had a significant contribution in the photocatalytic desulfurization reactions of Bi14W2O27/Bi2WO6 nanocomposite. The excellent photocatalytic desulfurization efficiency, good recyclability, solar-driven, and simple synthesis of Bi14W2O27/Bi2WO6 nanocomposite are promising for photocatalytic applications. تفاصيل المقالة -
حرية الوصول المقاله
4 - Efficient photocatalytic desulfurization of thiophene under visible light irradiation over flower-like AgBiS2 photocatalyst
Mehdi Mousavi-Kamazani Reza Rahmatolahzadeh Hassan NajafianHere, we report the production of hierarchical flower-like AgBiS2 nanostructuresby an amino acid-modified polyol route. This work indicates that by changing thepolyol process conditions including kind of capping agent, reaction time and refluxtemperature, the sheet-like أکثرHere, we report the production of hierarchical flower-like AgBiS2 nanostructuresby an amino acid-modified polyol route. This work indicates that by changing thepolyol process conditions including kind of capping agent, reaction time and refluxtemperature, the sheet-like, cone-like, sphere-like and flower-like morphologies ofAgBiS2 micro/nanostructures can be prepared. The phase, elemental composition,morphology and optical characteristics of as-prepared AgBiS2 nanostructures wereanalyzed by UV–Vis, FESEM, XRD, and EDS techniques. After characterization ofthe products, the AgBiS2 nanostructures were employed as novel photocatalystsfor oxidative desulfurization of thiophene/n-octane solution as model fuel undervisible light illumination. Results demonstrate that hierarchical flower-like AgBiS2photocatalyst with desirable band gap energy (2.44 eV) has high photocatalyticdesulfurization performance of about 89% after 2 h of visible light irradiation.As well as, the effects of morphology, photocatalyst dosage and reusability ofthe AgBiS2 nanostructures on the photocatalytic performance were evaluated.The excellent photocatalytic activity of AgBiS2 photocatalyst can be attributedto the strong visible light absorption, high separation rate of electron–hole pairs,special hierarchical structures and suitable band gap energy. Moreover, a reliablephoto-oxidation desulfurization mechanism was discussed according to theactive species trapping experiments, which revealed the photo-generated h+ and•O2− radicals were the main active species in the photocatalytic desulfurizationprocess. تفاصيل المقالة
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