In‐Situ Ni Leaching Induced the Formation of Amorphous High‐Entropy Layered Hydroxides for Boosting the Oxygen Evolution Reaction

ABSTRACT Activity, stability, and cost are three critical merits that need to be considered when designing OER electrocatalysts for practical applications. So far, most research on OER catalysts has mainly focused on enhancing the catalytic activity of OER and reducing the cost of the materials; systematic exploration of strategies for improving catalytic stability is still relatively scarce. In this study, a high‐entropy layered double hydroxide catalyst (CoNiFeCrRu@NF, HE‐LDH@NF) with excellent activity and stability was synthesized in situ on Ni foam (NF) by the dissolution of Ni 2+ from NF induced by Ru 3+ . As anticipated, the as‐prepared CoNiFeCrRu@NF LDH exhibits significantly better OER performance than its quaternary counterparts (CoNiFeCr@NF LDH, CoNiFeRu@NF LDH) and other analogs. It demonstrates a low overpotential of 256 mV at a current density of 100 mA cm −2 and a Tafel slope of 49.6 mV dec −1 in 1.0 M KOH, with excellent stability over 100 h without decay. This work verifies the efficacy of high‐entropy design and the synergistic effects of incorporating multiple elements on OER performance. It also clarifies new ideas for the application of advanced high‐entropy materials in energy conversion and storage.