Ir-Doped Co(OH)2 nanosheets as an efficient electrocatalyst for the oxygen evolution reaction

Abstract

In recent years, Co-based metal–organic frameworks (Co-MOFs) have received significant research interest because of their large specific surface area, high porosity, tunable structure and topological flexibility. However, their comparatively weak electrical conductivity and inferior stability drastically restrict the application of Co-MOFs in the synthesis of electrocatalysts. In this study, ZIF-67 was grown on nickel foam by a room temperature soaking method, and then Ir–Co(OH)₂@ZIF-67/NF was assembled by a hydrothermal method. The prepared Ir–Co(OH)₂@ZIF-67/NF nanosheets exhibit remarkable conductivity, larger electrochemical active surface area and wider electron transport channels. Only ultralow overpotentials of 198 mV, 263 mV, and 300 mV were needed for Ir–Co(OH)₂@ZIF-67/NF to reach the current densities of 10 mA cm⁻², 50 mA cm⁻², 100 mA cm⁻², meanwhile, no obvious degradation of the current density at 10 mA cm⁻² was observed for about 16 h. This work may provide a promising strategy for developing high-performance MOF-derived materials as electrocatalysts for the OER under alkaline conditions.