Interface triggered phosphate-functionalized NiCo oxide for boosting water oxidation reaction

Abstract

Surface grafting presents a promising approach for enhancing the performance of electrocatalysts in recent energy conversion systems. Herein, we focus on designing phosphate-anchored NiCo oxide on nickel foam (NF) for the oxygen evolution reaction (OER) and overall water splitting reaction (OWS) through a multimode synthesis approach. Experimental and theoretical findings demonstrate the remarkable tunability of phosphate functionalized NiCoO/NF, which enhances the OER activity, leading to increased current density, and decreased overpotential. Phosphate anchoring accelerates OER kinetics by modifying the rate of hydroxide ion movement, due to the overlap of phosphate energy states on the metal surface. This creates new energy states near the Fermi level, facilitating efficient intermediate adsorption. Additionally, PO4-NiCoO/NF outperforms IrO2 in overall water splitting, exhibiting an overpotential difference of 50 mV at 100 mA cm−2. Furthermore, the excellent reaction stability of the robust PO4-NiCoO/NF structure highlights its well regulated electronic environment and potential for electroactive behavior.