One-Step Synthesis of Ultrathin High-Entropy Layered Double Hydroxides for Ampere-Level Water Oxidation

Abstract

The development of high-entropy anodes, known for their excellent catalytic activity for water oxidation, can depress the energy consumption of hydrogen production by water electrolysis. However, the complex preparation methods and poor stability hindered their practical application. In this work, a one-step co-precipitation method has been modified to rapidly synthesize ultrathin high-entropy layered double hydroxide containing Ni, Co, Fe, Cr, Zn. Through the rational selection of metal elements, the stability of the optimized anode under Ampere-level current density has been significantly improved. Compared to NiFe-LDH, the active site leaching of high-entropy LDH is reduced by 42.7%, and as a result, it achieves a performance decay that is approximately eight times lower than that of NiFe-LDH. Experiment results show that the active sites in the high-entropy LDH can maintain a relatively low oxidation state both before and after activation, thus preventing material deactivation caused by excessive oxidation.