Strong interfacial bonded In_4/3P₂S₆/TiO₂ S-scheme junction with multi-channel charge transport for boosting photocatalytic water reduction

The rational design of a heterostructural photocatalysts with efficient charge separation and accelerated interfacial charge transfer holds great promise for boosting photocatalytic activity. Herein, we have developed a unique hierarchical In_4/3P₂S₆/TiO₂ heterojunction with P–O interfacial bonding for photocatalytic water reduction. By integrating emerging In_4/3P₂S₆ nanosheets through intense interfacial coupling effect, the optimized In_4/3P₂S₆/TiO₂ heterostructure exhibits a remarkably enhanced photocatalytic H₂ evolution activity compared to that of pristine TiO₂. Combined experimental and theoretical results confirm that multiple interfacial bonded step-scheme (S-scheme) charge transfer pathways are established in the In_4/3P₂S₆/TiO₂ photocatalyst, which synergistically promote charge separation and transfer through the robust interfacial electric field and rapid charge migration pathways formed by interfacial bonds. This study emphasizes the significance of developing novel interfacial bonded In_4/3P₂S₆-based S-scheme heterostructures, paving a new strategy towards enhancing photocatalytic activity for H₂ evolution.