Bimetallic Hofmann-Type Metal–Organic Framework Nanoparticles for Efficient Electrocatalysis of Oxygen Evolution Reaction

Metal–organic frameworks (MOFs) are promising platform materials for the electrocatalytic oxygen evolution reaction (OER). Here, Hofmann MOFs are applied as platforms to study the interaction between different metal elements and their influence on the OER activity. In all the MOFs, the Fe/Co mixed Hofmann MOF (CoFe-PYZ) demonstrates the lowest overpotential of 300 mV at 10 mA cm–2 in alkaline conditions (pH = 13). The Tafel slope of (CoFe-PYZ) is 44 mV dec–1. The enhanced catalytic activity is mainly attributed to the synergistic effects between Co2+ and Fe2+ ions, which is confirmed via XPS and density-functional theory (DFT) calculations.