Alternate Layers of Cobalt Doped Tungsten Oxide and Reduced Graphene Oxide Composite as Electrode Material for Supercapacitor

Abstract

Composites consist of layers of cobalt doped tungsten oxide and reduced graphitic oxide was prepared using jet nebulized spray pyrolysis technique. A mixture of ammonium tungstate and cobalt acetate solution was coated on glass substrate at 380 °C using jet nebulized spray pyrolysis technique. Spray technique is used to form the reduced graphene oxide (rGO) layer over the first layer and again ammonium tungstate and cobalt acetate solution coated over the surface of rGO and then calcined in nitrogen atmosphere at 450 °C for 2 h. The composite were characterized using XRD, SEM, PL, CV and EIS studies. The SEM and XRD reveal the layered structure. Cyclic voltammetry reveals the high specific capacitance 500 Fg-1 at 5 mV s-1 scan rate for 2 M Na2SO4 as electrolyte. Layered structure of CoWO4/rGO/CoWO4 composite enhances the specific capacitance. EIS gives the electrical series resistance of 7.9 Ω. The layered CoWO4/rGO/CoWO4 composite can be suitable electrode materials for supercapacitor.