Charge Regulation on Hybrid Nanosheet Stereoassembly via Interfacial P-O Coupling Enables Efficient Overall Water Splitting

Precise regulation on interfacial electronic coupling is essential to achieve efficient catalysts with tailored electrocatalytic behaviors but remains challenging. Herein, a straightforward topochemical strategy is presented to realize Co-based heterostructured nanofiber stereoassembled with P-O coupled nanosheet (CoHF/P-O). By constructing well-defined metal oxide/phosphide interface, prominent electron redistribution can be established via interfacial P-O coupling, which is strongly correlated with the catalytic activities. Density functional theory calculations indicate that the rational interface engineering renders accelerated charge transfer and more importantly, optimized surface adsorption/desorption behaviors, contributing to boosted kinetics for both hydrogen evolution reaction and oxygen evolution reaction. Particularly, CoHF/P-O featuring promoted intrinsic activity and accessible active sites exhibits intriguing activity and stability at higher current densities in alkaline media, surpassing commercial Pt/C and Ir/C. This study is expected to demonstrate noteworthy promise of covalent coupling toward modulated electronic environment and interface chemistry for electrocatalytic applications and beyond.