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Cerium vanadate/modified bentonite (CeVO4/mbt) nanocomposite with different composition percentages was synthesized through a simple one-step hydrothermal method at 180 ℃, and then its photocatalytic activity was evaluated by decolorizing methylene blue (MB) in an aqueous solution under light exposure. In order to increase the surface area as an important parameter in photocatalytic processes, bentonite was modified by ball mill method. The structural and optical properties of the synthesized composites were determined by XRD, FT-IR, DRS, FESEM, EDS, and BET measurements. XRD and EDS results confirmed the successful synthesis of pure CeVO4. FESEM images and EDS mapping showed a proper distribution of rice-like CeVO4 nanoparticles on bentonite. The removal efficiency of MB with only 0.1 g of CeVO4/mbt nanocomposite in 15 min was about 99%, which is significant compared to neat bentonite and pure CeVO4 with efficiency of 30% and 57%. The mentioned nanocomposite followed the first-order kinetics, had a reaction rate constant equal to 0.1483 min–1, and showed acceptable stability in five consecutive cycles. [ABSTRACT FROM AUTHOR]

In order to improve the desulfurization efficiency of petroleum derivatives, Ce0.5Bi0.5VO4/rGO nanocomposite was synthesized by sonochemical method. The prepared nanocomposites were characterized by XRD, FESEM, EDS, FT-IR, BET, and DRS analyses. XRD analysis shows that the synthesized nanocomposite is amorphous. FESEM images showed that nanostructures with a smaller particle size distribution were synthesized under optimal conditions, i.e. controlling the synthesis temperature between 0 and 5 °C. The results of desulfurization showed that nanocomposites containing reduced graphene oxide (rGO) have higher photocatalytic efficiency than pure samples, the main reason of which can be better charge separation in the samples through the π electron in the rGO structure. The highest amount of desulfurization of CeVO4/rGO, BiVO4/rGO, and Ce0.5Bi0.5VO4/rGO nanocomposites was 95.62, 91.25, and 96.38%, respectively, after exposure to UV light for 40 min. The enhancement of photocatalytic activity of Ce0.5Bi0.5VO4/rGO composite could be attributed to the efficient separation of electron–hole pairs and the inhibition of recombination. Desulfurization in the presence of hydrochloric acid and hydrogen peroxide increased the efficiency by 12%, which is a significant amount. [ABSTRACT FROM AUTHOR]

In this study, manganese was doped to ZnO by the hydrothermal method and calcined at different temperatures consist of: 3%MZ800, 6%MZ800, 9%MZ800, 9%MZ300, and 9%MZ400. The structural and optical properties of the samples were characterized using XRD, SEM, TEM, EDS, BET, DRS, and atomic spectroscopy analysis. Photocatalytic oxidative desulfurization of the solutions containing sulfur compounds was investigated by using the synthesized samples. 9%MZ400 showed the most desulfurization efficiency (95.99 ± 0.8%) for dibenzothiophene solution and (94.96 ± 1.3%) for AW 402 as a real sample of fuel in the presence of H2O2 and CH3COOH under visible-light irradiation (200 W tungsten). The leaching of Zn and Mn metal ions from photocatalyst isn't occurred in this process. The optimum amounts of H2O2, CH3COOH and dosage of photocatalyst were obtained in desulfurization process. Also kinetics of desulfurization and stability of photocatalyst were investigated. [ABSTRACT FROM AUTHOR]