Simultaneous electrical and defect engineering of nickel iron metal-organic-framework via co-doping of metalloid and non-metal elements for a highly efficient oxygen evolution reaction

Abstract

Metal-organic frameworks (MOFs) are promising electrocatalysts for oxygen evolution reaction (OER) due to their large amounts of active sites reacting with water molecules and desired adsorption/desorption characteristics with oxygen intermediate. However, the intrinsically low electrical conductivity of MOFs hinders their commercialization for the highly efficient OER catalyst. Here, we report 2D morphological NiFe MOF electrocatalyst co-doped with metalloid and non-metal elements for the enhanced OER performances. Te metalloid incorporation on MOFs facilitates electron transfer from transition metals of MOFs to embedded metalloids, which improves OER kinetics enabling favorable adsorption of oxygen intermediate on the surface of the electrocatalyst. Incorporated halogen Cl element could effectively induce defects on MOF as leach out from the surface of electrocatalyst during OER, allowing more active sites exposed to reactants. With the synergistic effect of metalloid (Te) and halogen (Cl) doping on NiFe MOF, the Te and Cl co-doped NiFe MOF growth on Ni foam (NF) present an excellent OER property requiring low overpotential for 224 mV at 30 mA cm-2 in alkaline condition and long-term stability over 120 h.