One-step Preparation and Electrochemical Performance of 3D Reduced Graphene Oxide/NiO as Supercapacitor Electrodes Materials

In this study, by using dispersions of graphene oxide (GO) and nickel nitrate (Ni(NO3)(2)center dot 6H(2)O) with different ratios as precursors, three-dimensional self-supported reduced graphene oxide/NiO composites (3D rGO/NiO) were prepared via a one-step hydrothermal method. The analysis results (XRD, SEM, etc) indicate that NiO nanoparticles are homogeneously dispersed on the surface of graphene layers. The specific capacitance of 3D rGO/NiO composite reaches 1208.8 F.g(-1) at a current density of 1 A.g(-1) when the mass ratio of GO and Ni(NO3)(2)center dot 6H(2)O is 1 : 4. With the current density increasing from 0.2 to 10 A.g(-1), the specific capacitance retention of this composite is higher than 72.6%. After 10000 cycles, the specific capacitance of 3D rGO/NiO at a current density of 10 A.g(-1) remained at 93% of the initial specific capacitance. All of these demonstrated that the composite possesses good rate capability and cycle stability. The 3D rGO/NiOcomposite has excellent electrochemical performances when compared with pure NiO or rGO, which is attributed to the synergistic effect between NiO and rGO.