2D Nanosheet-Structured Ag/Ag₂O@Bi₂MoO₆/ZnO Composites Enhanced with Photocatalytic Degradation and Photolytic Water to Hydrogen Performance

By constructing heterojunctions through the conjugation of semiconductors with narrow bandgaps and improving absorption capability in the visible light region based on the surface plasmon resonance (SPR) effect of noble metals, the highly efficient photocatalytic performance of ZnO-based composites can be achieved. In this paper, Ag/Ag₂O@Bi₂MoO₆/ZnO composites were prepared by a hydrothermal synthesis method combined with photo-deposition technique. Compared with ZnO, the composites exhibit a significant red shift and enhancement of visible light absorption. The results of photoluminescence tests and electrochemical experiments show that the synergistic effect of the heterostructure formed by Bi₂MoO₆ and ZnO in composite materials, the sensitization effect of Ag₂O, and the SPR effect of Ag result in an accelerated photo-response speed of electrons in the composite material, and the multi-pathway charge transfer channels suppress the recombination of electrons and holes, thereby enhancing photocatalytic activity. In the multi-mode photocatalytic degradation experiments, the degradation efficiency of crystal violet (CV) by Ag/Ag₂O@Bi₂MoO₆/ZnO is higher than that of other comparative systems. Meanwhile, the hydrogen production of Ag/Ag₂O@Bi₂MoO₆/ZnO (t = 8 h) is 13 times higher than that of commercially available TiO₂ in the experiment of photocatalytic water splitting for hydrogen production. Combined with the results of the capture experiments and the electron paramagnetic resonance (EPR) analysis, it is speculated that the photocatalytic reaction mechanism of Ag/Ag₂O@Bi₂MoO₆/ZnO under the irradiation of different light sources is more inclined to the action of the single/double Z-scheme, which provides a new idea for the development of novel and efficient photocatalytic material.