Interfacial Fe−O−Ni−O−Fe Bonding Regulates the Active Ni Sites of Ni‐MOFs via Iron Doping and Decorating with FeOOH for Super‐Efficient Oxygen Evolution

Abstract

Abstract The integration of Fe dopant and interfacial FeOOH into Ni‐MOFs [Fe‐doped‐(Ni‐MOFs)/FeOOH] to construct Fe−O−Ni−O−Fe bonding is demonstrated and the origin of remarkable electrocatalytic performance of Ni‐MOFs is elucidated. X‐ray absorption/photoelectron spectroscopy and theoretical calculation results indicate that Fe‐O−Ni−O−Fe bonding can facilitate the distorted coordinated structure of the Ni site with a short nickel–oxygen bond and low coordination number, and can promote the redistribution of Ni/Fe charge density to efficiently regulate the adsorption behavior of key intermediates with a near‐optimal d‐band center. Here the Fe‐doped‐(Ni‐MOFs)/FeOOH with interfacial Fe−O−Ni−O−Fe bonding shows superior catalytic performance for OER with a low overpotential of 210 mV at 15 mA cm −2 and excellent stability with ≈3 % attenuation after a 120 h cycle test. This study provides a novel strategy to design high‐performance Ni/Fe‐based electrocatalysts for OER in alkaline media.