Co3O4 nanowire arrays freely standing on nickel foam were prepared by a hydrothermal method. The detailed microstructure and morphology of Co3O4 nanowire were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) etc. The results indicated that the Co3O4 nanowires have diameters of around 80 nm and composed of many nanoparticles with diameters of about 20 nm. The electrochemical results show that Co3O4 nanowires demonstrate enhanced specific capacitance (616 F g-1) and electrochemical reversibility, and the specific capacitance of nanowires only decreased 19% after 3000 charge-discharge cycles

Bo Ren and Meiqing Fan