Synthesis of reduced graphene oxide/tungsten trioxide nanocomposite electrode for high electrochemical performance

A facile and well-controllable reduced graphene oxide/tungsten trioxide (rGO/WO3) nanocomposite electrode was successfully synthesized via an electrostatic assembly route at 350 rpm for 24 h. In this study, hexagonal-phase WO3 (h-WO3) nanofiber was well distributed on rGO sheets by applying optimal processing parameters. The as-synthesized rGO/WO3 nanocomposite electrode was compared with pure h-WO3 electrode. A maximum specific capacitance of 85.7 F g−1 at a current density of 0.7 A g−1 was obtained for the rGO/WO3 nanocomposite electrode, which showed better electrochemical performance than the WO3 electrode. The incorporation of WO3 into rGO could prevent the restacking of rGO and provide favourable surface adsorption sites for intercalation/de-intercalation reactions. The impedance studies demonstrated that the rGO/WO3 nanocomposite electrode exhibited lower resistance because of the superior conductivity of rGO that improved ion diffusion into the electrode. To evaluate the contribution of WO3 to the rGO/WO3 nanocomposite, the influence of mass loading of WO3 on the capacitance was investigated.