Constructing the CoO/Co4N heterostructure with an optimized electronic structure to boost alkaline hydrogen evolution electrocatalysis

Developing cost-efficient electrocatalysts with high-performance and durability toward the alkaline hydrogen evolution reaction (HER) is essential for the application of alkaline electrolyzers, but remains a big challenge. Here, we report the fabrication of the CoO/Co4N heterostructure electrocatalyst and its remarkable HER performance in alkaline electrolytes. Density functional theory (DFT) calculations and experimental results indicate that the electron transfer between CoO and Co4N leads to enhanced H2O adsorption, optimized hydrogen adsorption, and promoted Had diffusion, which contribute to the outstanding HER activity with a relatively low overpotential of 27 mV to achieve the current density of 10 mA cm−2.