Preparation of a Bimetallic NiFe-MOF on Nickel Foam as a Highly Efficient Electrocatalyst for Oxygen Evolution Reaction

A series of bimetallic metal-organic frameworks (MOFs) were prepared on three-dimensional nickel foam (NF) using a one-pot synthesis, marked as NiFe-MOF/NF. The structure of the as-prepared NiFe-MOF/NF was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), FT-IR and Raman. Compared with the monometallic Ni-MOF material, the incorporation of Fe greatly changes the inherent properties of Ni-MOF. Electrochemical measurement results show the optimized NiFe-MOF/NF [Ni : Fe=3 : 7 (molar ratio)] has better electrocatalytic performance and the current densities of 50 mA cm(-2) and 100 mA cm(-2) have low overpotentials of 225 mV and 251 mV, respectively, for the oxygen evolution reaction in alkaline solution. In particular, the inverse curve of linear sweep voltammetry shows an ultralow overpotential of only 160 mV at current density of 10 mA cm(-2). NiFe-MOF/NF also has excellent stability and can run continuously for at least 50 h. NiFe-MOF/NF has remarkable OER performance, which is mainly due to the high conductivity, the large specific surface area and the synergistic effects of Fe and Ni in MOFs. The work presents a general strategy for the synthesis of electrocatalytic materials for effective and scalable electrocatalytic water oxidation.