Lattice Oxygen-Modulated High-Entropy Layered Double Hydroxides for Energy-Efficient and Chloride-Resilient Sustainable Seawater Electrolysis

Seawater electrolysis offers a promising route for sustainable hydrogen production, but practical implementation remains challenging due to competitive chlorine evolution and catalyst degradation under highly corrosive conditions. Herein, a nonnoble metal-based high-entropy layered double hydroxide (HE-LDH) composed of Ni, Co, Fe, Cr, and Bi is prepared as a bifunctional electrocatalyst. Benefiting from the abundant active sites, tuned electronic structure, and multielemental synergistic effect, the electrocatalyst exhibits an overpotential of 266 mV and 160 mV for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) at 10 mA cm–2, respectively, in alkaline seawater. Further, the assembled anion exchange membrane (AEM) electrolyzer delivers a current density of 1.12 A cm–2 at 2.2 V and maintains stable operation for 700 h at 500 mA cm–2. The experimental and theoretical studies indicate the entropy-induced enhanced electrochemical kinetics and anticorrosion properties for efficient and durable seawater electrolysis.