AgBr@TiO2/GO ternary composites with enhanced photocatalytic activity for oxidation of benzyl alcohol to benzaldehyde

摘要

AgBr@TiO2/GO (graphene oxide) ternary composite photocatalyst was synthesized by fabricating core-shell-structured AgBr@TiO2 and anchoring it onto the surface of GO. The obtained samples were characterized by transmission electron microscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, ultraviolet-visible (UV-Vis) diffuse reflectance spectrum, and photoluminescence (PL) spectroscopy. It was found that the AgBr nanoparticles were prone to aggregation while the core-shell-structured AgBr@TiO2 possessed excellent dispersity. PL analysis revealed that the ternary-structured AgBr@TiO2/GO could effectively promote the separation rate of electron-hole pairs. Photocatalytic oxidation of benzyl alcohol to benzaldehyde under visible-light irradiation was selected as probe reaction to evaluate the photocatalytic activity of the different samples. It was found that the AgBr@TiO2/GO ternary composite exhibited evidently improved photocatalytic activity compared with AgBr, AgBr@TiO2, and AgBr/GO. On the basis of the experiment results, the photocatalytic oxidation mechanism of benzyl alcohol over AgBr@TiO2/GO is tentatively discussed.