Electronic Structure Engineering of Ni ₂ P via Er/Fe Co-Doping for Enhanced Oxygen Evolution Reaction Electrocatalysis

The oxygen evolution reaction (OER) is a critical yet kinetically sluggish process in water electrolysis for hydrogen generation, owing to its multistep, four-electron transfer. This necessitates the development of efficient catalysts to accelerate the reaction. Herein, Er/Fe-codoped Ni2P supported on nickel foam (Er/Fe−Ni2P/NF) was fabricated via an electrodeposition−phosphorization approach to explore the Er/Fe synergistic effects on OER dynamics. The results demonstrate that Er/Fe codoping effectively modulates the electronic structure of the catalyst and accelerates charge transfer kinetics. The optimized catalyst exhibits superior performance requiring only 208 ± 1 mV to achieve 10 mA cm−2 with a low Tafel slope of 33.66 mV dec−1, along with durability over 50 h of continuous testing. In situ Raman and infrared spectroscopic investigations demonstrate that Er/Fe codoping not only reduces the formation potential of NiOOH but also accelerates its formation kinetics. Density functional theory (DFT) calculations further elucidate that doping alters the *O adsorption configuration, while Er/Fe codoping further optimizes the reaction pathway, reducing the energy barrier and thus achieving exceptional OER catalytic performance.