Electrochemical performance and material characterization of reduced grapheneoxide (rGO) / titanium dioxide (TiO2) composite as electrodes for supercapacitors

Reduced Graphene Oxide/ Titanium Dioxide (rGO/ TiO₂) composite was synthesized by onestep hydrothermal reaction with a view to investigating the performance as electrodes for supercapacitors. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) analysis revealed that graphite oxide (GO) was successfully transformed to reduced graphene oxide (rGO) after hydrothermal reduction and the relevant peak was observed at 2θ=26⁰. Investigations on electrochemical properties of rGO/TiO₂ based supercapacitors revealed improved performance on charge/discharge cycles in comparison to supercapacitors based on pure TiO2. Also it has low self- discharge rate with 1.42 V initial voltage and 1.43 V final voltage after nine circles. The specific capacitance of rGO/ TiO₂ composite was 242 Fg^-1 while that for rGO and TiO₂ are 12.8 Fg-1 and 109 Fg^-1 respectively. After applied current density is increased from 0.024 to 0.127 Ag-1, the specific capacitance of rGO / TiO₂ remains about 80% of its initial voltage. The specific capacity is expected to improve further by using rGO/TiO₂/Polyaniline composite and the investigations are in progress.