Self-supported hydrothermal synthesized hollow Co3O4 nanowire arrays with high supercapacitor capacitance

We report a facile hydrothermal synthesis method for the large-area growth of self-supported hollow Co3O4 nanowire arrays. The Co3O4 nanowires have an average diameter of 200 nm and grow vertically to the substrates forming aligned nanowire arrays. Interestingly, the as-prepared Co3O4 nanowire arrays combine properties of hollow structure and quasi-single crystallinity. A plausible formation mechanism of hollow Co3O4 nanowire arrays is proposed here. The Co3O4 nanowire arrays grown on the nickel foam are tested as a cathode electrode material for supercapacitor by cyclic voltammograms (CVs) and galvanostatic charge–discharge tests in 1 M KOH. The self-supported hollow Co3O4 nanowire arrays exhibit superior…