MIL-101(Fe)-derived nickel–iron quasi-metal organic framework as efficient catalyst for oxygen evolution reaction

Abstract

Metal-organic frameworks (MOFs) have emerged as promising precursors for the development of efficient non-noble metal electrocatalysts for oxygen evolution reaction (OER). Quasi-metal–organic frameworks, characterized by partially fractured connections between metal nodes and organic ligands, have attracted significant attention due to their large exposed active interfaces. To stimulate the development of quasi-MOF-based materials as OER catalysts, herein a Ni-Fe quasi-MOF catalyst was prepared through the pyrolysis of MIL-101(Fe) and subsequent ion exchange with Ni²⁺. The optimum catalyst MIL-101(Fe)₃₅₀-Ni exhibits the lowest overpotential (290 mV) to achieve a current density of 10 mA cm⁻², the smallest Tafel slope (89 mV dec^–1) and the largest double-layer capacitance (0.268 mF cm⁻²). Furthermore, the current density drops only by ∼5 % (from 10 to 9.45 mA cm⁻²) after 20 h durability test. Experimental analysis suggests that the enhanced OER performance arises from the strong coupling effect between Fe and Ni, which improves the electron transfer efficiency and facilitates the active species generation. This work provide a feasible direction for constructing bimetallic quasi metal–organic frameworks to enhance the electrocatalytic OER performance and stability.