Iron modulated high entropy engineering boosting alkaline oxygen evolution.

Development and synthesis of cost-effective, efficient, and stable electrocatalysts for the oxygen evolution reaction (OER) play a pivotal role in advancing large-scale hydrogen production through water electrolysis. Herein, a unique cauliflower-like high-entropy alloy FeCoNiZnP catalyst was successfully synthesized on nickel foam through a facile one-step electrodeposition strategy. The as-prepared catalyst demonstrates outstanding OER performance in alkaline conditions, achieving an ultralow Tafel slope of 30 mV dec-1 along with remarkably low overpotentials of 226 mV and 278 mV at current densities of 10 mA cm-2 and 100 mA cm-2, respectively. Notably, the catalyst exhibits extraordinary durability, maintaining its initial morphological integrity and elemental composition even after 700 h of continuous operation under high-current-density conditions, as confirmed by post-stability characterization. Experimental analysis reveals that the incorporation of Fe significantly enhances the catalytic activity by optimizing the electronic structure and facilitating rapid charge transfer during the OER process. The synergistic interplay between Fe and the other constituent elements (Co, Ni, Zn, P) creates multiple active sites and modulates the adsorption energy of oxygen intermediates as revealed by density functional theory (DFT) calculations, thereby substantially improving reaction kinetics. This multi-element collaboration not only accelerates the oxygen evolution process but also ensures structural stability through entropy stabilization effects. Our findings highlight the critical role of Fe in high-entropy alloy systems for OER catalysis and offer valuable design principles for developing advanced multi-component electrocatalysts. This work establishes a new paradigm for engineering high-performance, durable electrocatalysts through strategic elemental combinations in high-entropy systems.