VO_x-doped CoP catalysts with synergistic dual-active configuration for boosting hydrogen evolution kinetics

Hydrogen evolution reaction (HER), is of great significance to harvest H₂ via energy-saving alkaline water electrolysis yet still challenging. Integrating heterogeneous materials is effective in designing favorable electrocatalysts for water dissociation (WD) and H-immediate involved adsorption/desorption behavior and triggering positive interactions to break the kinetics limitation. Herein, a promising configuration of a vanadium-oxide species integrated with cobalt-phosphide plane that grown on the nickel foam (labeled as VO_x-CoP/NF), is demonstrated to boost the alkaline HER kinetics comprehensively. The doped vanadium-oxide species preferentially perform the WD process to generate H-intermediates. Meanwhile, interaction between VO_x and CoP induce the electronic redistribution that optimizes 3d-2p orbital hybridization state, which balances the adsorption strength of H* to facilitate the hydrogen transfer and enrichment. Eventually, VO_x-CoP/NF exhibits supereminent alkaline HER performance with an overpotential of only 65/245 mV at 10/400 mA cm⁻², superior to individual CoP and most representative cobalt-phosphide candidates. A flowing anion exchange membrane (AEM) urea-assisted water electrolyzer with VO_x-CoP/NF as a bifunctional catalyst, is assembled and achieves a satisfactory performance, verifying its practical feasibility for efficient H₂ production. The concept exemplified in this work is that synchronous optimization of elementary reaction step kinetics of HER through reasonable constructing well-defined configuration is instructive for the design of HER electrocatalysts.