Facile synthesis and excellent electrochemical properties of CoMoO4 nanoplate arrays as supercapacitors

Abstract

CoMoO₄ nanoplate arrays (NPAs) were grown directly on Ni foam via a template-free hydrothermal route. The morphology of CoMoO₄ NPAs was examined by scanning and transmission electron microscopy and the phase structure of nanoplates (NPs) was analyzed using X-ray diffraction spectroscopy. Based on a series of time-dependent experiments, a possible growth mechanism for this structure was proposed. The CoMoO₄ NPAs supported on Ni foam could be directly used as integrated electrodes for electrochemical capacitors. Such unique array architectures exhibited remarkable electrochemical performance with a high specific capacitance of 1.26 F cm⁻² at a charge and discharge current density of 4 mA cm⁻² and 0.78 F cm⁻² at 32 mA cm⁻² with an excellent cycling ability (79.5% of the initial specific capacitance remained after 4000 cycles). The superior electrochemical performances could be attributed to the open network structure constituted of interconnected CoMoO₄ NPAs directly grown on current collectors that could improve electron transport and enhance electrolyte diffusion efficiency.