CuO nanoparticles supported on carbon microspheres as electrode material for supercapacitors

C/CuO nanocomposites were prepared by hydrothermal treatment of copper nitrate with starch, followed by H 2 O 2 oxidation and calcination. Structure characterizations show that high crystalline CuO nanoparticles with average size of ca. 40 nm are monodispersed on carbon microspheres. When used as electrode material for supercapacitors, the C/CuO nanocomposite exhibits high specific capacitance of 205 F g −1 at a current density of 1 A g −1 and excellent rate capacity (78 % capacitance was retained when the current density increased from 0.5 to 10 A g −1 ). It also shows good cycling stability with capacitance retention of 91 % after 1,000 cycles.