A Novel CdS/g-C3N4 Composite Photocatalyst: Preparation, Characterization and Photocatalytic Performance with Different Reaction Solvents under Visible Light Irradiation

CdS/graphtic carbon nitride (CdS/g-C3N4) hybrid materials were fabricated by thermal polymerization and hydrothermal methods using Cd(CH3COO)(2)center dot 2H(2)O, thioacetamide, and melamine as precursors. The structural and optical properties of the as-synthesized samples were investigated by X-ray powder diffraction, UV-vis diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, etc. A coupled system toward the selective oxidation of benzyl alcohol to benzaldehyde and the reduction of nitrobenzene into aniline was used to estimate the photocatalytic performance of CdS/g-C3N4 composite photocatalysts under visible light illumination. Results indicate that the CdS/g-C3N4 sample exhibits an outstanding photocatalytic performance for selective oxidation of benzyl alcohol and reduction of nitrobenzene. Meanwhile, benzotrifluoride is the best reaction medium among the screened solvents. Further research demonstrates that the selective oxidation of benzyl alcohol to benzaldehyde is induced by the photoexcited holes and the reduction of nitrobenzene into aniline is triggered by the photoexcited electrons. Additionally, the catalyst can be recycled several times without noticeable deactivation.