Strong interfacial coupling for NiS thin layer covered CdS nanorods with highly efficient photocatalytic hydrogen production

The construction of heterojunctions is beneficial to improve the separation efficiency of photogenerated electron-hole pairs, so as to enhance the activity of photocatalysts. Herein, NiS thin layer covered CdS nanorods (NiS/CdS) were synthesized by a two-step hydrothermal approach. Under the irradiation of visible light, the optimal NiS/CdS covered heterojunctions showed high photocatalytic stability and excellent hydrogen evolution rate up to 401.7 mmol g(-1) h(-1), which is higher than that of most CdS-based photocatalysts. The apparent quantum efficiency of NiS/CdS at 420 nm was 1.5%. The formation of NiS/CdS heterojunctions with large intimate contact area leads to strong interfacial coupling between NiS thin layers and CdS nanorods. This promotes the separation and migration of photoinduced electron-hole pairs and provides more active sites for redox reactions, thus improving the activity of photocatalysts. This work presents new ideas for the design of high-performance photocatalysts for H-2 production.