Regulating the coordination environment of a metal–organic framework for an efficient electrocatalytic oxygen evolution reaction

Abstract

The oxygen evolution reaction (OER) plays a vital role in fuel cells, water splitting and metal–air batteries. Efficient electrocatalysts could overcome the higher overpotential of the OER, improve electron transfer efficiency, and promote water decomposition. In this work, a novel metal–organic framework (MOF) with efficient OER electrocatalytic performance (defined as FeCo-L₁L₂) was successfully prepared by a free assembly of metal ions (Fe and Co), 2,5-dihydroxyterephthalic acid (defined as L₁) and 4,6-dihydroxyisophthalic acid (defined as L₂). The overpotential was only 283 mV at the current density conditions of 10 mA cm⁻² with a Tafel slope of 31.6 mV dec⁻¹. Its excellent OER performance is attributed to the synergistic effect of the bimetals of FeCo-L₁L₂ and the coordination environment optimization created by the dual ligands. This work not only improved the catalytic performance of MOFs in the OER but also proposed a new strategy for the structural design of MOFs.