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

Abstract

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-intense adsorption will poison the active sites. Herein, the adsorption ability of NiFeP is modulated 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 of ^*OH/^*H on the active sites. The balanced ^*OH/^*H adsorption facilitates the water dissociation and hydrogen evolution 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 231 mV under 30 wt% KOH. The balanced ^*OH/^*H adsorption ability in NiFePF facilitates the desorption of ^*OH and alleviates the poisoning active center, limiting the surface hydroxylation of NiFePF to a few nanometers. This enables NiFePF to remain stable for 360 h, demonstrating its commercial potential.