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 NiCoFeOx/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 NiCoFeOx/NF can be ascribed to the simultaneous incorporation of Ni and Co into FeOx/NF, boosting the intrinsic catalytic activities by altering the crystal and electronic structures. With electron redistribution happening in the tri-component NiCoFeOx/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 NiCoFeOx catalysts for active electrocatalysis. Abstract: (Figure presented.).