Regulating Volmer–Tafel Kinetics in NiPt_1% Alloy by Oxyphilic Y-Doped NiO for Enhancing Large-Current Hydrogen Evolution

Developing highly efficient catalysts with ultralow-loading metal is still hindered by the sluggish Volmer–Tafel kinetics for the alkaline hydrogen evolution reaction (HER). Herein, an efficient catalyst was designed and constructed on nickel foam by integrating oxyphilic Y-doped NiO with NiPt 1% nanocrystalline via a facile one-step electrodeposition. It requires only 21.2 and 178.5 mV to achieve 10 and 1000 mA cm –2, with a low Tafel slope of 27.8 mV dec –1 . Furthermore, it provides an ultrahigh mass activity of 42.7 mA μg p t –1 @ 100 mV and a high stability over 2000 h at 1 A cm –2 almost without potential decay. In-situ experiments and D 2 O electrolysis tests reveal that the oxyphilic Y-NiO component not only reduces the activation energy of NiPt 1% alloy by 32% and enhances its surface hydrogen (*H) coverage 7.8 times but also markedly boosts the Volmer step. Density functional theory calculations further reveal that Y-NiO strengthens water adsorption and shifts both Volmer and Tafel steps on the NiPt 1% alloy surface from nonspontaneous to spontaneous, while reducing their energy barriers by 32 and 23%, respectively. This work presents an effective approach for regulating the Volmer–Tafel process in ultralow-loading metal alloys for alkaline HER.