One-Step Synthesis of Rod-Shaped NiFe-MOF as a Highly Efficient Oxygen Evolution Catalyst

Abstract

Development of low-cost, highly active catalyst for efficient oxygen evolution reaction based on earth-abundant metals is still a great challenge. Here, we report that a rod-like bimetallic NiFe metal-organic framework (NiFe-MOF) can directly act as a highly efficient oxygen evolution reaction (OER) catalyst synthesized by a convenient-to-operate hydrothermal method. The rod-like NiFe-MOF can derive 10[Formula: see text]mA[Formula: see text]cm[Formula: see text] with a low overpotential of only 26[Formula: see text]mV, and its Tafel slope is 40.82[Formula: see text]mV[Formula: see text]dec[Formula: see text], which is superior to that of monometallic Ni-MOF or Fe-MOF, and even can be comparable to that of RuO2. To identify the origin of enhancing OER activity, we resorted to X-ray diffraction, scanning electron microscope, transmission electron microscope, high resolution transmission electron microscopy image and nitrogen adsorption–desorption techniques and various electrochemical techniques to probe it gingerly. The results indicate that its high electrochemically active area and the synergistic effect of bimetallic node could be responsible for the surprisingly high catalytic performance of the NiFe-MOF. These results suggest that this kind of bimetallic MOF (NiFe-MOF) could be a promising electrocatalyst for oxygen evolution reaction.