Construction of NiCo₂S₄/ZnCdS Schottky Junction with Unidirectional Interfacial Electron Transfer for Boosting Photocatalytic Hydrogen Production

The efficient separation of photogenerated electron–hole pairs is a critical challenge that hampers the performance of photocatalytic systems. In this work, a NiCo2S4/ZnCdS (NiCo2S4/ZCS) Schottky junction was constructed by a simple physical mixing method. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) results proved that NiCo2S4 is an amorphous material, and density functional theory (DFT) calculations confirmed the metallic nature of NiCo2S4. The light absorption capacity of the NiCo2S4/ZCS heterojunction is significantly enhanced with the NiCo2S4 loading. The formation of Schottky junctions between NiCo2S4 and ZnCdS results in photogenerated electron transfer and spatial separation and prevents the recombination of charge carriers. Therefore, the optimized 20% NiCo2S4/ZCS exhibits a remarkable photocatalytic hydrogen evolution (PHE) activity of 25 mmol g–1 h–1, which is 4.79 and 150.6 times higher than that of ZnCdS alone and NiCo2S4. This work provides a successful strategy for preparing a ZnCdS-based Schottky junction to promote PHE activity.