Coherent Heterointerface Engineering for Synchronized Proton-Coupled Electron Transfer in Photocatalytic Hydrogen Evolution
Photocatalytic hydrogen evolution fundamentally requires synchronized proton-coupled electron transfer. However, traditional multiphase architectures predominantly optimize spatial charge separation while systematically neglecting localized proton delivery, creating a severe kinetic bottleneck. Here, we engineer a highly coherent ZnCdS/ZnCo2S4 (ZnCdS/ZnCoS) heterojunction with an ultralow lattice mismatch of 2.5% to construct an efficient bioinspired catalytic cascade. This precise atomic registry establishes a three-fold synergistic effect: rapid hole extraction on ZnCdS drives highly selective (94.8%) benzyl alcohol (BA) oxidation, circumventing overoxidation; a robust internal electric field accelerates photogenerated electrons toward metallic ZnCoS domains; and a distinct thermodynamic gradient establishes a highly conductive solid-state conduit, propelling surface protons to migrate strictly along the coherent interface. Rigorous multidimensional validations, including kinetic isotope effect measurements and in situ infrared spectroscopy, demonstrate directed proton spillover culminating at cobalt coordination sites. Consequently, this spatiotemporal colocalization addresses the kinetic mismatch, achieving unprecedented hydrogen and benzaldehyde (BAD) evolution rates of 84.3 and 75.1 mmol g-1 h-1, respectively. This work establishes coherent interface engineering as a universal paradigm for synchronizing electron routing and proton spillover in advanced energy catalysis.