Electrochemical properties of Co-doped titanate nanotubes for energy storage

Abstract

Abstract Co-doped titanate nanotubes (TNTs) with a nominal composition of Co x Ti3-x O7(Na2- yHy·nH2O) (where 0 ≤ x ≤ 0.30) were successfully synthesized by hydrothermal route at a temperature of 130 °C for 24 h. The diameter of nanotubes was found to be on the 7 ∼ 20 nm. The synthesized samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Brunauer–Emmett–Teller (BET). The electrochemical properties were investigated by using cyclic voltammetry (CV) at different scan rates (2-200 mV/s) and galvanostatic charge-discharge (GCD) at different constant current densities in 6 M KOH. The electrochemical measurement showed the variation of the specific capacitances depending on the doping level. The specific capacitances of Co-doped TNTs significantly increased with increasing doping level. The electrochemical properties of TNTs can be improved by Co doping.