High‐Entropy Modified Spinel‐Type Co ₃ O ₄ Nanowires Enhance Activity and Stability for Water Oxidation

ABSTRACT Co 3 O 4 is considered a promising oxygen evolution reaction catalyst, but its performance is constrained by insufficient active site exposure, inefficient electron transfer, and poor stability. To address these issues, we designed a high‐entropy Co 3 O 4 (Co 1.4 (MnFeNiCu) 1.6 O 4 ). This material exhibits a low Tafel slope of 39.49 mV dec −1 . Notably, the Pt/C||Co 1.4 (MnFeNiCu) 1.6 O 4 electrode pair operated continuously for 2400 h at a high current density of 500 mA cm −2 under industrial conditions (30 wt.% KOH, 60 °C) in an anion‐exchange membrane electrolyzer. Advanced in situ spectroscopic techniques combined with density functional theory calculations confirm that the high activity of Co 1.4 (MnFeNiCu) 1.6 O 4 originates from enhanced participation of the lattice oxygen oxidation pathway. Furthermore, the high‐entropy effect stabilizes the oxidation state of Co and strengthens the metal‐oxygen bond, ensuring high stability. This study provides a strategy for designing high‐performance Co 3 O 4 , which will facilitate the development of industrial‐scale hydrogen production technologies.