An organic–inorganic poly(3,4-ethylenedioxythiophene) (PEDOT)/RuO2·xH2O nanocomposite (approximately 1 wt.% RuO2) has been successfully prepared for the first time under microwave irradiation within 5 min with power 900 W via in situ chemical polymerization. The morphology and structure of the resultant material is characterized by transmission electron microscope and Fourier transform infrared. Moreover, the electrochemical properties of the synthesized nanocomposite can be controlled by adjusting the annealing temperature, which is definitely illustrated by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectra. Electrochemical data have shown that the PEDOT/RuO2·xH2O nanocomposite annealed at 150 °C possesses the most favorable charge/discharge ability with a specific capacitance of 153.3 F g−1 at a current density of 150 mA g−1 and the high efficient utilization of PEDOT at various current densities. Furthermore, such composite has a less capacitance degradation of 23.8% after 1,000 continuous cycles. The improved electrochemical performance are mainly attributed to the large electroactive surface of nanocomposite and the existence of amorphous RuO2·xH2O particles as well as a synergistic effect of the polymer PEDOT and annealed RuO2·xH2O. Thus, the PEDOT/RuO2·xH2O nanocomposite annealed at 150 °C can act as a promising electroactive material for supercapacitor application.
