Nickel-regulated hierarchical bimetallic phosphides on an iron foam to promote ampere-level current density in the oxygen evolution reaction

Abstract

Strategically designing advanced electrocatalysts to accelerate the inherently slow oxygen evolution reaction (OER) remains a crucial yet demanding endeavor in electrocatalysis research. Herein, we present the synthesis of FeNiP nanorods with adjustable doping levels on FeNiOOH nanosheets fabricated on an iron foam. The as-prepared FeNiP/FeNiOOH-1 electrocatalyst demonstrated outstanding OER performance, requiring an overpotential of only 436 mV to reach an industrially relevant current density of 1 A cm⁻². The incorporation of Ni inhibits the formation of iron oxides, which was beneficial for the formation of highly active FeNiOOH, thereby increasing the number of active sites and enhancing OER activity. This research introduces a facile and scalable synthesis protocol for earth-abundant transition metal-based electrocatalysts through compositionally adjustable architectures, achieving superior OER performance in alkaline media.