3D MXene/Ag2S material as Schottky junction catalyst with stable and enhanced photocatalytic activity and photocorrosion resistance

A novel visible-light-driven uniform Schottky junction MXene/Ag2S catalyst is constructed by chemical deposition and electrostatically driven self-assembly to deposit Ag2S 3D MXene gel’s surface. In this study, various characterization tests show that MXene/Ag2S-2 photocatalyst has excellent visible light absorption performance under visible light (>420 nm). To explore the source of the excellent charge separation performance of Schottky junction, possible charge transfer mechanisms of Schottky junction, and the synergistic effect of silver ion plasmon resonance effect are proposed. We proved the charge transfer mechanism of the Schottky junction and also captured the active species capture experiments. It can be speculated that all active species affect the photocatalytic reaction in the order of O2− > e− > h+ > OH. Simultaneously, the photocatalytic system would have a small amount of silver ion reduction in the plasmon resonance effect during the photocatalysis process, which can be synergistic with the Schottky junction. Besides, the Schottky junction MXene/Ag2S has relatively stable photocatalytic performance and recovery capability. The current work demonstrates a mild, feasible, low-cost all-solid-state Schottky junction synthesis method to improve pollutants’ photocatalytic ability.