Boosting alkaline hydrogen evolution electrocatalysis through electronic communicating vessels on Co2P/Co4N heterostructure catalyst

Abstract Developing highly efficient non-noble metal-based electrocatalysts for alkaline hydrogen evolution reaction (HER) is crucial for sustainable fuel production. Although great efforts have been devoted to promoting the alkaline HER kinetics through accelerating the sluggish water dissociation step by incorporation of oxophilic sites, these strategies are mainly limited to constructing metal/hydroxide interface or heteroatoms doping. Herein, we report a rational construction of Co2P/Co4N heterostructure catalyst with a unique electronic communicating vessels (ECV) formed at the interface between Co4N phase and Co2P phase. Density functional theory (DFT) calculations and experimental results reveal that the ECV at the interface is beneficial for regulating the electronic structures of the two phases, and thereby leads to optimized adsorption strength of reaction intermediates (*H2O and *H), contributing to the outstanding alkaline HER performance with an overpotential of 40 mV to achieve the current density of 10 mA cm-2. This study opens a new avenue for tailoring the electronic structures through fabrication of electronic communicating vessels in the heterostructure electrocatalysts with enhanced electrocatalytic performances.