Atomic interfacial charge and energy transfer paths at MoS₂/Pd bonded defect-rich BiOCl interfaces for efficient photocatalysis

Construction of heterogeneous transmission interfaces that spatially separate Coulomb-bound electron-hole pairs in semiconductors allows exceptional control over optoelectronic properties, thereby enhancing the efficiency of solar energy conversion. In this study, we propose an effective photocatalyst for full water splitting named MS/BOC-x/Pd, comprising atomic layer of MoS₂ bonded to defect-rich BiOCl, and a non-plasmonic Pd oxidation co-catalyst is exclusively assembled on the sides to form a strong electronic coupling and maximize the trapping of holes. The presence of the Mo-S-Bi motif promotes rapid charge migration, resulting in impressive rates of H₂ and O₂ formation (165 and 9.17 μmol g⁻¹ h⁻¹, respectively), without the requirement of sacrificial agents or sensitizers. Through experimental and theoretical investigations, we discovered that the occupation of sulfur atoms in oxygen vacancies extends the overlap of surface charges, thereby facilitating the separation of inner/interfacial electron-hole pairs. The Mo-S-Bi bond provides directional guidance for charge transfer to the surface redox sites. These findings provide valuable insights for the future design of highly efficient photocatalysts for solar energy conversions.