A dual-interfacial system with well-defined spatially separated redox-sites for boosting photocatalytic overall H₂S splitting

Integration of high activity, selectivity, and stability is urgently desired to achieve more ideal photocatalysts. Herein, we reported the rational design of MoS₂-MnS@(In_xCu_1-x)₂S₃ (M-M@IC) catalysts with dual interface to integrate separated redox sites for boosting photocatalytic hydrogen sulphide (H₂S) splitting and the resource utilization of sacrificial reagents (Na₂S/Na₂SO₃). The spatially separated reduction (MnS) and oxidation (In₂S₃) sites in MnS/In₂S₃ heterojunction, on which MoS₂ and Cu were selectively loaded, can drive electrons and holes near the surface to flow along opposite directions, while the heterojunction between MnS and In₂S₃ inhibits the bulk charge recombination. Furthermore, the introduction of Cu atoms creates a d-band center, which favours mass diffusion of reactants/products species and greatly facilitates sunlight response. The MoS₂ serves to provide abundant sites for proton reduction due to the unsaturated-sulfur-edge-rich (US-rich) nature. As a result, the M−M@IC shows a state-of-the-art visible-light photocatalytic H₂ evolution rate (126.5 mmol g^-1h⁻¹), inspiring stability of >50 h, and nearly 100% selectivity toward value-added Na₂S₂O₃ production under optimized condition. This work opens up new opportunities for the construction and design of spatially separated catalytic site in photocatalysts.