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.