Towards robust hydrogen evolution electrocatalysts in immiscible copper–molybdenum alloys by amorphization

Abstract

Designing bimetallic alloys and providing dual active sites is an effective way to achieve efficient alkaline hydrogen evolution reaction (HER). However, the preparation and determination of an optimal composition remain significant challenges for immiscible alloys. In this study, the amorphous Cu–Mo alloys with a wide composition range were successfully prepared by magnetron sputtering. Among these alloys, the amorphous Cu₅₀Mo₅₀ alloy demonstrates excellent alkaline HER activity with low overpotentials of 57 and 149 mV at 10 and 100 mA cm⁻², respectively. Moreover, it demonstrates outstanding long-term stability at 300 mA cm⁻². The results demonstrate that an electronic interaction exists between the Cu and Mo atoms in the amorphous Cu₅₀Mo₅₀ alloy, where the Cu and Mo act as adsorption sites for OH and H intermediates, respectively. Furthermore, the amorphous Cu₅₀Mo₅₀ alloy also exhibits favorable intermediates adsorption and water dissociation abilities, which facilitate the alkaline HER process. The research provides a novel insight into the rational design and preparation of advanced alkaline HER catalysts.