Heterogeneous Bimetallic Phosphide Ni 2 P‐Fe 2 P as an Efficient Bifunctional Catalyst for Water/Seawater Splitting

Abstract Developing high‐performance and cost‐effective bifunctional electrocatalysts for large‐scale water electrolysis is desirable but remains a significant challenge. Most existing nano‐ and micro‐structured electrocatalysts require complex synthetic procedures, making scale‐up highly challenging. Here, a heterogeneous Ni 2 P‐Fe 2 P microsheet is synthesized by directly soaking Ni foam in hydrochloric acid and an iron nitrate solution, followed by phosphidation. Benefiting from high intrinsic activity, abundant active sites, and a superior transfer coefficient, this self‐supported Ni 2 P‐Fe 2 P electrocatalyst shows superb catalytic activity toward overall water splitting, requiring low voltages of 1.682…