CdS Nanorods with an Optimized ZnS Coating as Composite Photocatalysts for Enhanced Water Splitting under Solar Light Irradiation

Narrow bandgap semiconductor CdS demonstrates promising photocatalytic ability for water splitting under visible light response. However, the inherent photocorrosion and high recombination rate of electron–hole pairs constrain its wide application. Here, highly stable ZnS nanoparticles were coated onto CdS nanorods to form Cd/Zn-based composite photocatalysts. The Cd/Zn-based composite photocatalysts demonstrate enhanced specific area and conductivity, reduced photocorrosion, prolonged lifetime of photogenerated electrons, and countless heterojunction structures. The fabricated Cd/Zn-3 composite photocatalyst demonstrates an optimal thickness of the ZnS coating on CdS, which delivers 7.3 mA cm–2 photocurrent density, 1.1 mmol g–1 h–1 H2 production rate, and remarkable long-term stability under solar light irradiation.