Cu- and S-Doped Heteropolyacid Co 2 Mo 10 as Electrocatalysts for Efficient Hydrogen Evolution.

This study employed polyoxometalate Co ₂ Mo ₁₀ as a precursor and a two-step method to prepare carbon cloth-supported Cu _x S-CoS ₂ -MoS ₂ materials. The morphology and structure of the materials were characterized using XRD, XPS, SEM, TEM, and other techniques. Interestingly, changes in the reducing gas during the calcination process could adjust the product morphology, thereby altering catalytic activity. Electrochemical results indicated that the Cu _x S-CoS ₂ -MoS ₂ nanomaterials prepared under an NH ₃ atmosphere exhibited unique morphology and structural advantages. They demonstrated significant electrocatalytic activity for the hydrogen evolution reaction (HER) in alkaline and acidic electrolytes (overpotentials of 108 and 196 mV at a current density of 10 mA cm ^-2 , lower than the overpotentials of 143 and 226 mV obtained under a H ₂ -Ar atmosphere during calcination) and excellent long-term durability. These findings provide insights and methods for synthesizing multicomponent electrocatalysts with enhanced catalytic performance.