Hydrothermally Constructed ZnIn2S4/SrSnO3 Type-II Heterojunction for Highly Efficient Photocatalytic Hydrogen Evolution

To achieve high-performance photocatalysts, efficient separation of photogenerated charge carriers is critical to prolonging their lifetime and thereby enhancing the activity of the hydrogen evolution reaction. In this work, we rationally designed and synthesized a nanoflower-like SrSnO3/ZnIn2S4 heterostructure by in situ embedding SrSnO3 nanorods within the layered framework of ZnIn2S4. Experimental results demonstrate that the 0.8%-SrSnO3/ZnIn2S4 composite exhibits a hydrogen evolution rate 13.79 times higher than that of pure ZnIn2S4 under simulated solar irradiation. This dramatic enhancement stems from the formation of a Type-II heterojunction at the interface, where the staggered band alignment generates an internal electric field that drives spatial separation of electrons and holes, effectively suppressing recombination and promoting charge utilization. This study validates that the strategic incorporation of a small amount of SrSnO3 into ZnIn2S4 represents a highly effective approach to significantly boost photocatalytic hydrogen production performance.