RF magnetron sputtering synthesis of three-dimensional graphene@Co3O4 nanowire array grown on Ni foam for application in supercapacitors

Three-dimensional graphene@Co3O4 nanowire array grown on Ni foam as a binder-free supercapacitor electrode were prepared, in which the graphene was prepared by the facile Radio frequency (RF) magnetron sputtering method. The electrochemical properties were tested by the cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectra in detail. The graphene@Co3O4 nanowire array grown on Ni foam exhibited an higher pseudocapacitive behavior comparing to pure Co3O4 nanowire array grown on Ni foam. The result was attributed to that the graphene prepared by RF magnetron sputtering method was high conductivity and high contact interaction between graphene and Co3O4 array. This work provided a novel method to synthesize 3D porous array electrode materials based on graphene for application in electrochemical energy storage.