Resolving Electronic Conflicts in Bifunctional Electrocatalysis via Extracellular Polymeric Substances‐Mediated Spin‐State Engineering

This work presents a bio‐inspired strategy for spin‐state engineering in bifunctional electrocatalysis using extracellular polymeric substances (EPS). The Co 2 P/Ni 2 P‐EPS 2 /NF catalyst is designed to resolve the inherent electronic conflicts between the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) by enabling potential‐driven charge redistribution and dynamic spin‐state reconstruction. The catalyst achieves low overpotentials of 49.1 mV for HER and 198.5 mV for OER at 10 mA cm −2 , demonstrating exceptional bifunctional electrocatalytic activity and stability. Furthermore, the catalyst operates efficiently under solar irradiation, achieving a cell voltage of only 1.45 V for overall water splitting, showcasing its potential for sustainable hydrogen production driven by renewable energy. The combination of experimental data and theoretical insights reveals that high‐spin Co 3+ for OER and low‐spin Ni 2+ for HER optimally modulate the adsorption of reaction intermediates. This work introduces a novel approach to electrocatalysis and offers a scalable and economically feasible solution for solar‐driven hydrogen production from water.