Amorphous High‐entropy Phosphide Nanosheets With Multi‐atom Catalytic Sites for Efficient Oxygen Evolution

Abstract The alkaline oxygen evolution reaction (OER) mainly encompasses four elementary reactions, involving intermediates such as HO*, O*, and HOO*. Balancing the Gibbs free energies of these intermediates at a single active site is a challenging task. In this work, a high‐entropy metal‐organic framework incorporating Fe, Ni, Co, Cu, and Y metal elements is synthesized using an electrodeposition method, which then serves as a template for preparing a high‐entropy phosphide/carbon (FeCoNiCuYP/C) composite. Notably, the obtained composite exhibits an amorphous structure with multiple catalytically active sites. Combined theoretical calculations and experimental measurements reveal the critical roles of Co/Ni and Fe atoms in tuning the electronic structure of FeCoNiCuYP and optimizing the binding strength of intermediates. Furthermore, Fe and Ni/Co sites prefer to stabilize the HO* and HOO* intermediates respectively, conducive to breaking their scaling relation of Gibbs free energy during OER. Owing to its fine‐tuned composition and the synergistic effect of multiple active sites, the FeCoNiCuYP/C electrocatalyst demonstrates superior OER performance in alkaline solutions, requiring a mere 316 mV overpotential to yield 100 mA cm−2 current density with excellent stability. This work provides an innovative route to design efficient high‐entropy electrocatalysts, holding significant promise for cutting‐edge electrocatalytic applications.