Modulating Band Structure and Charge-Carrier Dynamics in MoS2/ZnIn2S4 Heterojunction Composites for High-Efficiency Photocatalytic H2 Production

The high demand for fossil fuels in human activities and industrial production has intensified environmental pollution, global warming, and energy shortages, making the development of alternative energy and energy-storage technologies imperative. Among these approaches, photocatalytic conversion of solar energy into hydrogen is regarded as a sustainable solution to the energy and environmental crises. However, the rapid recombination of photogenerated charge carriers and the lack of effective active sites severely limit photocatalytic performance. To address these challenges, heterojunction engineering is often employed to suppress electron-hole recombination and enhance photocatalytic H2 evolution efficiency. A MoS2/ZnIn2S4 heterojunction was constructed via the in situ growth of MoS2 nanorods on the surface of ZnIn2S4. The introduction of MoS2 not only broadens the light-absorption range of ZnIn2S4, but also suppresses the recombination of photogenerated charge carriers, thereby significantly enhancing the photocatalytic H2 evolution performance of ZnIn2S4. The optimal MoS2 loading was 30 wt%, at which the photocatalytic H2 evolution rate reached 11.52 mmol·g−1·h−1, nearly 2.5 times that of pure MoS2. In addition, the catalyst maintained nearly unchanged activity after five consecutive cycles, indicating good stability and that photocorrosion was effectively suppressed in the presence of sacrificial reagents. The heterojunction formed between MoS2 and ZnIn2S4 shortens the charge-transfer pathway and improves the separation efficiency of photogenerated electrons and holes, thereby suppressing charge-carrier recombination and accelerating the photocatalytic H2 evolution re photocorrosion action.