Novel of TiO2/Ag3PO4/Bentonite Composite Photocatalyst: Preparation, Characterization, and Application for Degradation of Methylene Blue in Aqueous Solution

The present work is devoted to the synthesis of a novel photocatalyst of TiO2/Ag3PO4/bentonite composite and its utilization for degradation of methylene blue (MB) in aqueous solution under visible light irradiation. The synthesized catalyst was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, Brunauer-Emmett-Teller method and energy-dispersive X-ray techniques. Degradation conditions were optimized as pH of 7, catalyst loading of 0.1g, initial MB concentration of 50mg/L at room temperature with composition weight ratio of TiO2:Ag3PO4:bentonite corresponding to 1:0.15:1, respectively. Results indicated that photocatalytic activity of this material was significantly improved due to the combination of advantages of its components. Kinetics of degradation process fitted well with a pseudo first-order model. A possible degradation mechanism was proposed and analyzed in detail. In addition, recycling study demonstrated a high stability of the catalyst over five continuous cycles of MB degradation.