Phosphorus-Modified High-Entropy Layered Double Hydroxide for Enhanced Electrocatalytic Oxygen Evolution via d-Band Center Modulation.

Developing cost-effective, high-performance electrocatalysts for the oxygen evolution reaction (OER) is crucial but challenging. High-entropy layered double hydroxides (HE-LDHs) show promise due to their multi-metal synergy and structural complexity, yet their OER performance is limited by electronic and surface properties. This study combines theoretical and experimental methods to enhance OER by incorporating phosphorus (P) atoms in HE-LDHs, optimizing oxygen intermediate adsorption, and boosting OER activity and stability. A P-modified FeNiCoCuZn LDH catalyst (P-FeNiCoCuZn LDH) was synthesized via hydrothermal and low-temperature phosphatization processes, featuring phosphate anion intercalation and surface metal phosphides. The phosphate anions improve conductivity and stability, while surface P atoms adjust the electronic structure of metal sites, particularly Ni and Fe, reducing the energy barrier for the rate-determining step (*O→*OOH). The P-FeNiCoCuZn LDH achieves a low overpotential of 290 mV at 100 mA cm-2 and maintains stability for 100 hours in 1 M KOH. In-situ Raman spectroscopy shows the formation of highly active Ni(Fe)-OOH species during OER. This work offers a novel strategy for designing efficient water-splitting catalysts through in-situ heteroatom modification, advancing high-entropy materials in electrocatalysis.