Graphical Abstract

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 In4/3P2S6/TiO2 heterojunction with P-O interfacial bonding for photocatalytic water reduction. By integrating emerging In4/3P2S6 nanosheets through intense interfacial coupling effect, the optimized In4/3P2S6/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 S-scheme charge transfer pathways are established in the In4/3P2S6/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 In4/3P2S6-based S-scheme heterostructures, paving a new strategy towards enhancing photocatalytic activity for H2 evolution.