Experimental and computational analysis of Ni–P and Fe–P metal foams for enhanced hydrogen evolution reaction in alkaline media

Abstract

Electrochemical water splitting is a promising approach for sustainable hydrogen production, with the hydrogen evolution reaction (HER) playing a key role. Transition metal phosphides (TMPs) have emerged as efficient and cost-effective alternatives to Pt-based catalysts. In this study, we investigate Ni–P and Fe–P metal foams, utilising their porous structures to enhance catalytic activity. Electrochemical analysis reveals that Ni–P exhibits superior reaction kinetics (79 mV dec⁻¹) and a high electrochemically active surface area (41.8 mF cm⁻²). Density functional theory (DFT) calculations further confirm the role of phosphorus doping, with Ni(111)P_ads achieving a near-optimal Gibbs free energy (ΔG_H* = 0.01 eV). Comparative DFT analysis also reveals a trend in ΔG_H values for Ni(111) and Fe(110), demonstrating the impact of phosphorus incorporation on HER performance. These findings provide valuable insights into the design of porous TMP catalysts for efficient and scalable hydrogen production.