ZnO/CNT nanocomposite electrode for aqueous electrochemical supercapacitor

ZnO nanopowders are synthesised by a hydrothermal method followed by thermal decomposition. The phase and surface morphology of the obtained powders are characterised by X-ray diffraction, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). A ZnO/CNT composite electrode was prepared by mixing ZnO nanopowders with multiwalled carbon nanotubes in different proportions and electrochemically characterised by cyclic voltammetry in 0·1, 0·5 and 1M of KCl aqueous solutions at a scan rate of 100 mV s−1. The ZnO/CNT electrode provides the best performance, namely, 25·66 F g−1 in 0·5M KCl solution.