Cathodic electrodeposition activation of NiFe‐based metal–organic frameworks for enhanced oxygen evolution reaction

Abstract Electrodeposition activation of metal–organic frameworks (MOFs) has emerged as a promising strategy for the synthesis of highly efficient electrocatalysts for oxygen evolution reaction (OER). Herein, a cathodic electrodeposition method is presented to activate NiFe‐based MOF nanosheets on a nickel foam (NF) support to form a NiFe‐MOF/(oxy)hydroxide nanocomposite (A‐NiFe‐TDC). This activation route not only creates abundant defective structures but also involves partial valency reduction in Ni/Fe species and electron transfer to grow a new component of NiFe‐(oxy)hydroxide on the surface of the NiFe‐TDC MOF. By adjusting electrodeposition times and Ni/Fe mol ratios, the as‐prepared A‐NiFe‐TDC‐5 nanocomposite exhibits improved electrocatalytic performance for OER in an alkaline medium, achieving a high current density of 100 mA cm −2 at a low overpotential of 242.9 mV, a small Tafel slope of 24.9 mV dec −1 , and good long‐term stability over 450 h. After OER, A‐NiFe‐TDC‐5 is self‐reconstructed to form NiFe‐OOH nanosheets, contributing to optimizing the electronic structures and further improving the electrocatalytic activity and stability. This work provides a viable and effective electrodeposition activation method for the preparation of MOF‐based nanocomposites to boost the electrocatalytic performance for OER.