Boosting hydrogen evolution on NiFeZn electrocatalyst by defect surface modulation using alkali etching

Developing highly efficient catalysts using facile approaches is important for accelerating the slow reaction kinetics of the alkaline hydrogen evolution reaction (HER) and ensuring cost-effective hydrogen production. In this study, we reported a facile alkali etching method to boost the HER activity immediately after electrodeposition of a NiFeZn catalyst on Ti paper. During etching, (oxy)hydroxides were formed on the surface, and Zn species were etched from the deposits, which resulted in a roughened surface with more valleys generated between grains, facilitating a faster mass transport during the electrochemical reaction. The etched catalyst exhibited a boosted HER overpotential of 57 mV at −10 mA/cm2 and accelerated HER kinetic with Tafel slope of 97 mV/dec compared with that of the pristine catalyst. Our results demonstrated an efficient approach for boosting the catalyst activity in the alkaline HER.