Balanced Adsorption Ability of NiFeP by Nonmetal Doping for Boosting Water Dissociation Kinetics and Stability

Hydrogen evolution reaction (HER) under alkaline conditions is determined by the water dissociation process. Strengthening the adsorption ability of the electrocatalyst is crucial to promoting water dissociation in the alkaline HER, whereas too-intensified adsorption will poison the active sites. Herein, we modulate the adsorption ability of NiFeP by nonmetal F doping for an efficient and durable alkaline HER. F incorporation in NiFeP (NiFePF) tailors the electronic structure of Ni, Fe, and P, optimizing the adsorption affinity of *OH/*H on the active sites. The balanced *OH/*H adsorption facilitates the water dissociation of NiFePF, exhibiting the smaller overpotential of 233 mV at 100 mA cm-2. Furthermore, NiFePF achieves 1 A cm-2 at an overpotential of only 233 mV under 30 wt% KOH. Ex-situ analysis unraveled the surface reconstruction of NiFeP and NiFePF during HER. The balanced *OH/*H adsorption ability in NiFePF facilitates the desorption of *OH and alleviates the poisoning active center and surface hydroxylation, limiting the surface reconstruction of NiFePF to a few nanometers. This enables NiFePF to remain stable for 360 hours, implying its commercial potential.