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. [Display omitted] •Bimetallic organic framework {[MFe(tda)(H2O)]n (M = Mn/Co/Ni)} were synthesized.•The morphology can be efficiently changed by regulating the metal components.•Rod for MnFe, fan-shaped for CoFe and pompon-shaped for NiFe.•[NiFe(tda)(H2O)]n with pompon structure delivers extraordinary OER performance.