Facile Synthesis of MnO2/graphene Electrode by Two-steps Electrodeposition for Energy Storage Application

MnO2/graphene electrode was developed via anodic deposition of nanostructured MnO2 film on electrophoretically reduced graphene oxide (EPD-rGO) film. The electrodeposited MnO2, EPD-rGO and MnO2/EPD-rGO electrodes were characterized and investigated for supercapacitor application using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, fourier transform infrared spectroscopy, cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The electrophoretic deposition enables the development of rGO film composed of overlapped platelets of defective graphene sheets. The MnO2/ EPD-rGO electrode shows better specific capacitance and rate capability than MnO2 electrode; it exhibits specific capacitance of 822 Fg-1 and better cyclic stability at a current density of 1 mA cm-2. The large surface area and defective nature of EPD-rGO film in conjunction with an efficient utilization of MnO2 nanoparticles facilitated rapid ion transport and electrochemical cyclic stability, and hence offering the potential of the unique capacitive behavior. The obtained results indicate electrophoretic deposition could set a facile base for providing graphene-based materials, at room temperature without using harsh and toxic chemicals or high synthesis temperature.