Highly efficient noble-metal-free NiS/rGO/Cd0.3Zn0.7S nanorods in visible-light-driven H-2 evolution with enhanced surface photoinduced charge transfer

Effectively improving the separation efficiency of photoinduced carriers is of crucial importance for the design of photocatalysts with excellent hydrogen evolution activity. Herein, by combining CdZnS nanorods with rGO and further depositing NiS as cocatalysts, the separation and transfer of photoinduced carriers for CdZnS is significantly improved. Without using any noble metals as cocatalysts, the optimal NiS/0.5%rGO/Cd0.3Zn0.7S exhibits an outstanding H-2 evolution activity of 1058 mu mol h(-1) under visible light illumination, which is evidently better than that of pure CdZnS nanorods and most CdZnS-based photocatalysts reported previously. Our study indicates that the introduction of rGO can effectively assist the transfer of photoinduced electrons and evenly distributed NiS on the surface, as the active center for H-2 evolution reaction, can easily capture photoinduced electrons to participate in photocatalytic process. Thus, the synergistic effect of rGO and NiS is considered to be the main cause for the improved photocatalytic performance. This work could offer a facile and low-cost strategy for the construction of composite photocatalysts with high-efficiency hydrogen generation activity.