Surface conversion derived core-shell nanostructures of Co particles@RuCo alloy for superior hydrogen evolution in alkali and seawater

Hydrogen evolution reaction (HER) in alkali involves higher energy barriers and slow reaction kinetics due to involving water dissociation process. Catalysts with proper surface properties are highly needed to optimize the surface binding energy with reaction intermediates and enhance intrinsic catalytic activity. Herein, we present an effective strategy to construct a self-standing catalyst with core-shell structure, which is composited of metallic Co nanoparticles coated by RuCo alloy layer with optimized surface properties. The Ru attracts electrons from Co and optimizes the surface electronic structure. Theoretical calculations demonstrate that the water dissociation barrier on the Co surface is decreased from 0.65 eV to 0.58 eV after alloying with Ru. Experimental results reveal that the synthesized Co@RuCo-3 features highly efficient catalytic activity together with good stability at large current densities for HER in alkali, as well as in alkaline seawater and pure seawater.