Copper-doped nickel–iron metal/metal oxide electrode with improved performance by promoting synergistic effects in the oxygen evolution reaction

Advancing the performance of NiFe catalytic systems for oxygen evolution reaction (OER) is challenging, notably upon incorporating a third transition metal to create a trimetallic configuration. This study introduces a Cu-doped NiFe electrocatalyst, synthesized via a streamlined redeposition technique. The catalyst exhibits a Tafel slope of 38 mV dec and a low overpotential of 248 mV at a current density of 100 mA cm, plus a 2.5-fold boost in intrinsic activity. Density Functional Theory (DFT) and spectroscopic analyses demonstrate that Cu doping refines the electronic structure, enhancing charge density around the Fermi level and multiplying active OER sites. The Cu1Fe6Ni18 catalyst features robust Cu–O and Fe–O bond interactions, enhancing charge transport and OER kinetics. Our research elucidates the synergistic effects of Cu and Fe in a trimetallic system, offering an impactful approach to elevate trimetallic catalyst performance.