Efficient Schottky heterojunctions of CoP nanoparticles decorated Mn-doped CdS nanorods for photocatalytic hydrogen evolution by water splitting

This study reports novel noble-metal-free photocatalytic composites containing CoP nanoparticles modified Mndoped CdS (MCS) nanorods for producing H2 2 by water splitting. MCS nanorods are prepared with various molar ratios of Cd to Mn via a solvothermal method. Compared to other MCS samples, the MCS-8:3 sample with exceptional crystallinity and shorter radial transfer paths displays the highest H2 2 production rate, which is used for further modification. To mitigate the recombination of electrons and holes, CoP nanoparticles owning metallic properties are deposited onto the surface of MCS-8:3 as cocatalysts using a deposition-phosphorization method. The influence of the amounts of CoP on the morphology and H2 2 production rates was investigated. The testing results indicate that MCS/CoP-7% exhibits significantly enhanced photocatalytic H2 2 production rate of 40.5 mmol/g/h. This value is 4.7 times more than that of MCS-8:3, which is higher than most of the reported MCS-based catalysts. The optical and electrochemical experiments reveal that the established heterojunctions between MCS and CoP enable to improve the average charge lifetime, the separation and transfer of photo- generated charge. Furthermore, the band structures of the composites are also estimated. Combining with the XPS results and band structure, the enhanced photocatalytic performances can be attributed to the Schottky heterojunctions with the efficient electron-transfer pathway between MCS and CoP are proposed.