Design of three dimensional hybrid Co3O4@NiMoO4 core/shell arrays grown on carbon cloth as high-performance supercapacitors

Abstract

Electrodes with rationally designed hybrid nanostructure composites can have superior electrochemical performance for supercapacitors to single structured materials. In this work, the uniform three dimensional (3D) hybrid Co₃O₄@NiMoO₄ nanowire/nanosheet arrays directly grown on carbon cloth were designed and synthesized via a two-step hydrothermal method. A series of characterizations of SEM, XRD, XPS, TEM and N₂ adsorption/desorption isotherms were used to verify the hierarchical core/shell hybrid nanostructure of as-prepared products, which combines the advantages of the good rate capability of Co₃O₄ nanowires and the high surface area of NiMoO₄ nanosheets. As a binder-free electrode, the fabricated 3D hybrid nanocomposite achieves a high areal capacitance of 3.61 F cm⁻² at a current density of 3 mA cm⁻² and a capacitance retention of 82% with the increase of current density from 3 to 15 mA cm⁻². Besides, the hybrid nanostructured product also exhibits lower bulk resistance and lower charge transfer resistance than single structured Co₃O₄ material. The outstanding electrochemical behaviour and the facile fabrication process suggest that this hybrid nanoarchitecture material has potential application in high-performance supercapacitors.