Assembly of ZIF-67 nanoparticles andin situgrown Cu(OH)2nanowires serves as an effective electrocatalyst for oxygen evolution

Abstract

Due to the slow kinetics of oxygen evolution at the anode, the efficiency of electrocatalytic water decomposition is critically reduced, and its large-scale application is severely restricted. Therefore, it is urgent to develop electrocatalysts with excellent performance and stability to accelerate the oxygen evolution reaction (OER) reaction kinetics. Herein, a self-supporting binder-free electrocatalyst was successfully prepared usingin situgrown Cu(OH)2nanowires on CF as the carrier to grow ZIF-67viaa room temperature immersion method. The combination of Cu(OH)2nanowires and the unique structure of ZIF-67 forms a three-dimensional nanostructured catalyst, in which the unique structure and the existence of synergy may contribute to a larger electrochemical active surface area, expose more electrochemically active sites, adjust the electronic structure, and accelerate the rate of electron transfer, thus greatly improving the electrocatalytic activity and durability for OER. The as-prepared Cu(OH)2@ZIF-67/CF exhibited excellent OER performance under alkaline conditions and required overpotentials of 205 mV and 276 mV to drive current densities of 10 mA cm−2and 100 mA cm−2, respectively, with a small Tafel slope of 70.5 mV dec−1for OER. The stability test of Cu(OH)2@ZIF-67/CF at the current density of 10 mA cm−2displayed excellent stability for 22 h. This study provides a feasible strategy for the rapid preparation of low-cost and efficient electrocatalysts in alkaline media.