One-pot synthesis of pompon-like bimetallic organic framework for enhanced oxygen evolution electrocatalysis

Metal-organic frameworks (MOFs) are class of promising heterogeneous catalysis, but usually not directly employed for oxygen evolution reaction (OER) due to manipulating difficultly their composition and morphology. Herein, we present a facile one-pot solvothermal method to successfully synthesize diverse bimetallic organic framework {[MFe(tda)(H2O)]n (M = Mn/Co/Ni), tda = thiodiacetate}. Significantly, the morphology of [MFe(tda)(H2O)]n can be efficiently changed by regulating metal components. Among them, [NiFe(tda)(H2O)]n with unique pompon-like architecture not only can be directly used as electrocatalyst, but also delivers extraordinary OER performance with low overpotential of 264 mV at current density of 10 mA cm-2 in O2-saturated 1 M KOH solution, low Tafel slope of 53.9 mV dec- 1, and high durability after long-term testing. In addition, the effect of mixed ligands and metal ratio on morphology has also been investigated, which demonstrates the hierarchical structure of prepared materials plays a crucial role in enhancing OER activity.