Ultrathin core–shell Au@RuNi nanowires for superior electrocatalytic hydrogen evolution

Abstract

The rational design of cost-effective, highly efficient, and stable Ru-based electrocatalysts as substitutes for Pt in the hydrogen evolution reaction (HER) is highly desirable and has garnered significant attention. Constructing core–shell nanostructures has emerged as an effective approach for regulating the interaction among diverse components, potentially enhancing structural stability and catalytic activity. Herein, we report a facile synthesis of Au@RuNi NWs via the epitaxial growth of a uniform fcc-structured RuNi alloy layer on the surface of ultrathin Au NWs. The prepared Au@RuNi NWs exhibit a remarkable alkaline HER performance with only a 19 mV overpotential to achieve a current density of 10 mA cm⁻², with a small Tafel slope of 32.63 mV dec⁻¹ and outstanding stability. The ultrathin 1D core–shell nanowire structure and the alloying effect of Ni within the fcc-RuNi alloy shell layer facilitate the water dissociation, resulting in accelerated alkaline HER kinetics. This work provides a facile method to rationally design and synthesize core–shell Ru-based electrocatalysts for extraordinary HER performance under alkaline conditions.