Chemically Bonded V-ZnIn₂S₄/MoS₂ for Efficient Photocatalytic Hydrogen Evolution

The construction of Z-scheme heterojunctions is regarded as one of the most effective modification strategies for photocatalysts. However, how to improve the interfacial charge transfer efficiency to further enhance the photocatalytic activity remains an urgent issue to be addressed. In this study, sulfur vacancy-enriched ZnIn₂S₄/MoS₂ Z-scheme heterojunctions (V-ZIS/MS) containing interfacial Mo-S bonds was successfully synthesized using a hydrothermal method. The V-ZIS/2%MS showed the highest hydrogen evolution rate, achieving 19.21 ± 0.78 mmol·g⁻¹·h⁻¹ under visible light and 112.89 ± 10.98 mmol·g⁻¹·h⁻¹ under full-spectrum illumination, which are 5.07 and 4.41 times higher than ZIS (3.79 ± 0.79 mmol·g⁻¹·h⁻¹) and V-ZIS (4.36 ± 0.98 mmol·g⁻¹·h⁻¹) under visible light, respectively, outperforming most reported ZIS-based photocatalysts. This is because the composite of V-ZIS and MS enhanced its light absorption performance. More importantly, the formation of Mo-S bonds at the V-ZIS/MoS₂ interface facilitated efficient charge transfer and reduced interfacial resistance, leading to significantly improved photocatalytic activity. Cycling experiments further demonstrate that V-ZIS/2%MS exhibits considerable photocatalytic stability. X-ray diffraction analysis before and after the reaction further confirmed the structural stability of the catalyst. This work provides a certain reference for the preparation of high-performance ZIS-based photocatalysts.