Electronic structure engineering of CoS catalysts by rhenium modification for efficient alkaline hydrogen evolution

Abstract Fabricating a durable electrocatalyst with performance comparable to noble metals for the alkaline hydrogen evolution reaction (HER) remains a significant challenge. In this work, we introduce a highly efficient and robust electrocatalyst by incorporating rhenium (Re) atoms into CoS nanoflakes (Re‐CoS) for alkaline HER. The incorporation of Re atoms into the CoS lattice enhances the hybridization of Co 3d and S 2p orbitals, resulting in an optimized electronic structure that accelerates water dissociation on Co sites and optimizes hydrogen adsorption–desorption on S sites, thereby boosting the HER rate. The optimal Re‐CoS catalyst demonstrates a low overpotential of 72 mV at 10 mA cm −2 in 1 M KOH, along with excellent long‐term stability, maintaining its catalytic activity over 200 h without significant degradation. These results suggest that the incorporation of Re atoms into CoS effectively couples the water dissociation and hydrogen ad‐desorption steps of alkaline HER, offering a promising strategy for the development of noble metal‐like electrocatalysts.