Cobalt Modulation in NiFe-Based Metal–Organic Frameworks Enables Synergistic Enhancement of Oxygen Evolution Reaction in Alkaline Media

Abstract

Metal-organic frameworks (MOFs) have attracted significant interest as advanced electrocatalysts owing to their highly porous architectures and varied topological configurations. However, monometallic MOFs often suffer from insufficient active sites and a lack of electronic and synergistic effects, which limit their catalytic performance. In this study, a set of Co_xNiFe-MOF (x = 0.2, 0.4, 0.6, and 0.8 mmol) catalysts was prepared through a straightforward hydrothermal route, with NiFe-MOF employed as the precursor. Through systematic optimization of the Co content, the Co_0.6NiFe-MOF (x = 0.6 mmol) demonstrated optimal electrocatalytic activity for the oxygen evolution reaction (OER), attaining an overpotential as low as 316 mV under a current density of 10 mA cm⁻². This work offers a practical approach to implement trimetallic MOFs as catalysts for the OER.