Fabrication of noble-metal-free CdS nanorods-carbon layer-cobalt phosphide multiple heterojunctions for efficient and robust photocatalyst hydrogen evolution under visible light irradiation

Photocatalytic water splitting has aroused great interest as a clean and renewable energy conversion process. In this study, we prepared a novel noble-metal-free multiple heterojunction photocatalyst (CdS@C-CoP) composed of CdS nanorods, conducting carbon layer and CoP nanoparticles cocatalyst for the first time. The obtained CdS@C-CoP composites exhibited excellent performance and stability under visible light irradiation when it was used as photocatalysts for hydrogen evolution. For the optimum CdS@C-CoP sample, an average hydrogen evolution rate reached up to 10089 μmol g−1 h−1, nearly 6 fold as high as that of pure CdS. The enhanced photocatalytic hydrogen production rate can be ascribed to the synergistic effect between conductive carbon layer and surface cocatalyst CoP, which resulted in efficient separation of photoexcited charge carriers and abundant active sites for hydrogen reduction. This work presented a novel way to design composite photocatalyst with efficient hydrogen generation properties through combining two kinds of surface modification methods: thin carbon layer coating and surface cocatalysts loading.