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

Abstract

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 H_ad 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.