Facile synthesis of a medium-entropy CoNiFe subacetate nanoprism for high efficiency oxygen evolution reaction

The oxygen evolution reaction (OER) is an important half-reaction in rechargeable metal-air batteries and water splitting devices, and it suffers from slow kinetics due to the multiple step proton-electron coupled process. Therefore, the major challenge for the OER is to develop durable and low-cost electrocatalysts with high catalytic performance. Herein, a ternary metal CoNiFe subacetate nano prism (CoNiFe NP) was synthesized by a one-step hydrothermal method, with the aim of accelerating the water dissociation and improving the reaction rate using the synergy of the ternary metal. The results show that the electrocatalytic performance of the ternary metal CoNiFe layered double hydroxide is significantly improved compared with the binary metal and single metal catalysts. In particular, the overpotential of the prepared CoNiFe NP for the OER at 10 mA cm-2 is as low as 292 mV, and the Tafel slope is 75.6 mV dec-1. This work provides a new platform for the design of medium-entropy electrocatalysts using the interaction of polymetallic components. A one-step synthesis strategy was developed to synthesize a medium-entropy CoNiFe subacetate nanoprism, and the catalyst exhibited good catalytic performance for the oxygen evolution reaction.