Electrochemical properties of ruthenium oxide (RuO2)/oxidized multi-walled carbon nanotube (MWCNT) (RuO2/MWCNT) composite electrodes in supercapacitors were investigated. The electrodes were prepared by impregnating MWCNTs with different concentrations of RuCl3•xH2O solution, followed by chemical reduction and annealing at 150°C under a nitrogen atmosphere. RuO2 deposited on the MWCNTs was hydrous and amorphous when annealed at 150°C. Transmission electron microscopy (TEM) and Energy dispersive X-ray spectroscopy (EDX) analyses showed that the RuO2 particles had a uniform size distribution, confirming the presence of RuO2 in the prepared composites. Cyclic voltammetry analysis suggested that the specific capacitance of the 10 wt% RuO2/MWCNT composite electrode was significantly higher than those of the pristine MWCNT and 5 wt% RuO2/MWCNT electrodes in the same medium. This superior performance is probably attributable to the pseudocapacitance of amorphous RuO2.
Electrochemical properties, RuO2, Multi-walled carbon nanotubes, Supercapacitors