Electrochemical capacitance study on Co3O4 nanowires for super capacitors application

One-dimensional Co3O4 nanowires have been prepared by utilizing the ordered mesoporous silica material SBA-15 as template. The results of transmission electron microscope (TEM) and N-2 adsorption-desorption characterizations show that the Co3O4 nanowires possess a uniform size and a large Brunauer-Emmett-Teller (BET) surface area. Its electrochemical performance was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques in various concentration of KOH solution. This nanomaterial shows a small resistance, a high specific capacitance (SC), and a strong cyclic stability. The maximal SC value of 373 F center dot g(-1) was obtained in 6 M electrolyte under the scan speed of 3 mV center dot s(-1) at the first CV cycle. After 500 CV cycles, the SC value is about 90% of the original value. It is considered that the short path of ion transfer given by nanomaterial brought on the great pseudo capacitance performance.