Accelerated Charge Transfer in CoP@ZnIn ₂ S ₄ With Strong Electronic Coupling and Ohmic Contact for Enhanced Photocatalytic Hydrogen Evolution

Photocatalytic hydrogen production hinges on simultaneous construction of efficient hydrogen evolution sites and electron transport channels in photocatalytic materials. Here, CoP@ZnIn 2 S 4 (CP@ZIS) heterojunctions were successfully fabricated by in situ growing ZnIn 2 S 4 (ZIS) onto the metallic CoP (CP) nanorods. The CP@ZIS heterostructures are characterized by a strong electronic coupling between CP and ZIS, which enables rapid interfacial charge transfer and lowers the thermodynamic energy barrier for hydrogen evolution reaction. In contrast to conventional Schottky‐type contact between Pt and ZIS, an Ohmic contact is identified at the CP/ZIS interface, which allows CP to efficiently collect photogenerated electrons from ZIS. Accordingly, the optimal sample exhibits a superior photocatalytic hydrogen evolution rate of 11.28 mmol·g −1 ·h −1 under visible light irradiation ( λ ≥ 400 nm), which is 14.1‐fold higher than that of pristine ZIS and 1.83‐fold higher than that of Pt‐loaded ZIS. This work underscores the importance of cocatalyst–semiconductor interfaces and provides a promising paradigm for constructing photocatalytic heterostructures for high‐performance photocatalytic systems toward efficient hydrogen production.