Identifying the crystal and electronic structure evolution in tri‐component transition metal oxide nanosheets for efficient electrocatalytic oxygen evolution

Abstract Transition metal oxides (TMOs) nanosheets comprised of earth abundant Fe, Co, and Ni elements have been designed. Remarkably, the tri‐component NiCoFeO_x/Ni foam (NF) electrode delivers a high current density of 100 mA cm⁻² at an overpotential of only ≈383 mV for oxygen evolution reaction (OER), with prolonged electrochemical stability. The improved OER activity of NiCoFeO_x/NF can be ascribed to the simultaneous incorporation of Ni and Co into FeO_x/NF, boosting the intrinsic catalytic activities by altering the crystal and electronic structures. With electron redistribution happening in the tri‐component NiCoFeO_x/NF, the electron transfer from Co to Ni through the Fe acting as the electron transfer bridge renders Co more acidic (Lewis acid) to activate H₂O (Lewis base) molecules through Lewis acid‐base interaction. By identifying the interactions of Fe, Co, and Ni and electron redistribution in the tri‐component TMOs, this study provides new insights into the crystal and electronic structure evolution of tri‐component NiCoFeO_x catalysts for active electrocatalysis. Abstract image