A Facile Immersion Strategy for Molybdate-Modified Co/Co(OH)2@Cu Nanowires as High-Efficiency and Durable Electrocatalysts for Alkaline Hydrogen Evolution.

Developing efficient and durable earth-abundant electrocatalysts for the alkaline hydrogen evolution reaction (HER) is limited by the sluggish water dissociation kinetics. Herein, a facile immersion strategy was proposed to synthesize molybdate species-modified Co/Co(OH)2@Cu (MCC@Cu) nanowires as high-efficiency alkaline HER electrocatalysts. The introduced molybdate species remarkably promotes the water dissociation process, enhances active site exposure, and improves charge transfer, as revealed by the in situ Raman tests and electrochemical analysis. As a result, the as-prepared MCC@Cu nanowires have a low overpotential of 37 mV at 10 mA cm-2, which is much lower than that of the molybdate-free one (184 mV). This work offers a facile and scalable method for the design of molybdate-modified electrocatalysts toward alkaline HER.