Facile synthesis of Co3O4 nanowires grown on hollow NiO microspheres with superior electrochemical performance

Abstract

The NiO/Co3O4 core/shell composites as a promising supercapacitor material have been fabricated by facile hydrothermal process. The structure and morphology of the NiO/Co3O4 core/shell composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results indicated that the NiO hollow spheres were decorated by Co3O4 nanowires, and the nanowires were composed of nanoparticles. Electrochemical properties were characterized by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy. The results suggested that the NiO/Co3O4 core/shell composites had good electrochemical reversibility and displayed superior capacitive performance with large capacitance (510Fg−1). Moreover, NiO/Co3O4 core/shell composites showed excellent cyclic performanceafter 1000 cycles.