Visible light photosensitization of ZnO by Bi2MoO6 and AgBr: Role of tandem n n heterojunctions in efficient charge transfer and photocatalytic performances
Abstract Efficient visible light active ZnO/Bi2MoO6/AgBr nanocomposites were fabricated using ultrasonic assisted method. Crystallinity, structural, morphological, optical, and textural features of the photocatalysts were investigated by XRD, SEM, TEM, EDX, FT IR, UV Vis DRS, PL, and BET techniques. Photocatalytic performance of the ZnO sample was remarkably increased by combining with Bi2MoO6 and AgBr, due to formation of tandem n n heterojunctions. The as prepared ZnO/Bi2MoO6/AgBr nanocomposites exhibited excellent photocatalytic activity and stability under visible light in comparison with the ZnO, ZnO/Bi2MoO6, and ZnO/AgBr samples. About ~97% of RhB was removed in 70 min by the optimized ZnO/Bi2MoO6/AgBr (20% nanocomposite, which is 76.4, 4.75, and 17.3 times as fast as the ZnO, ZnO/Bi2MoO6 (20% and ZnO/AgBr (20% photocatalysts, respectively. It was confirmed that due to improved utilization of visible light, considerable separation of the charge carriers, and enlarged surface area, the ZnO/Bi2MoO6/AgBr (20% nanocomposite exhibited greatly improved photocatalytic activity in degradations of various dye contaminants under visible light illumination. In addition, plausible photocatalytic degradation mechanism for the highly enhanced performances were also proposed.