Superficial state regulation in double-anion-coupled Ni nanostructure for efficient hydrogen evolution reaction

Abstract Because nickel-sulfide based electrode materials are regarded as appealing hydrogen evolution reaction (HER) electrocatalysts, various strategies have been designed to enhance their HER activity. Herein, we adopt a simple electrodeposition method to synthesize amorphous nickel sulfide electrocatalysts. Through altering the added amounts of electroplating bath consisting of NiCl 2 and thiourea (TU), the HER electrocatalytic activity in alkaline electrolyte of these nickel sulfides can be optimized, and it exhibits a low overpotential of 130 mV at a current density of −10 mA cm −2 , a small Tafel slope of 91 mV dec −1 , and high electrochemical stability. The experimental analysis and density functional theory calculations suggest that the excellent electrochemical activity is ascribed to the coordination regulation of Ni nanostructures decorated with sulfur and oxygen anions. These findings demonstrate a simple and effective method to explore high efficiency electrocatalysts to HER.