Engineering morphologies of cobalt oxide/phosphate-carbon nanohybrids for high-efficiency electrochemical water oxidation and reduction

Active non-noble metal catalysts plays a decisive role for water electrolysis, however, the rational design and development of cost-efficient electrocatalysts with Pt/IrO2-like activity is still a challenging task. Herein, a facile one-step electrodeposition route in deep eutectic solvents (DESs) is developed for morphology-controllable synthesis of cobalt oxide/phosphate-carbon nanohybrids on nickel foam (CoPO@C/NF). A series of CoPO@C/NF nanostructures including cubes, octahedrons, microspheres and nanoflowers are synthesized, which show promising electrocatalytic properties toward oxygen and hydrogen evolution reactions (OER/HER). Such surface self-organized microstructure with accessible active sites make a significant contribution to the enhanced electrochemical activity, and hybridizing cobalt oxide with cobalt pyrophosphates and carbon can result in enhanced OER performance through synergistic catalysis. Among all nanostructures, the obtained microspherical CoPO@C/NF-3 catalyst exhibits excellent catalytic activities for OER and HER in 1.0 M KOH, affording an anodic current density of 10 mA cm(-2) at overpotentials of 293 mV for OER and 93 mV for HER, with good long-time stability. This work offers a practical route for engineering the high-performance electrocatalysts towards efficient energy conversion and storage devices. (c) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.