Interfacial Electron Transfer and Synergistic Effects on NiCo(CA)@M Microbars That Boost the Alkaline Oxygen Evolution Reaction

Abstract

The development of oxygen evolution reaction electrocatalysts with a low cost, high activity, and strong stability is of great significance to the breakthrough of energy conversion technology. Herein, a composite material (NiCo(CA)@M) was obtained by growing nickel-cobalt nanoparticles on MIL-88A in situ by a simple two-step solvent thermal method. The results show that NiCo(CA)@M composite has rich active sites, and the formation of the composite induces charge redistribution between NiCo(CA) and MIL-88A, effectively reducing the reaction energy barrier, while growth in situ was conducive to the improvement of material stability. Impressively, the NiCo(CA)@M catalyst achieved a current density of 10 mA cm−2 in alkaline electrolyte required an overpotential of only 270 mV and the Tafel slope was 69 mV dec−1. At the same time, the NiCo(CA)@M catalyst had excellent stability at a current density of 10 mA cm−2, and after the 16 h i-t test, the catalyst still had 91.1% current density retention. The electrocatalytic activity did not decay significantly after 2000 CV cycles.