Facile Synthesis of Fe3O4/graphene Nanosheets with High Conductivity for Application in Supercapacitors

The Fe3O4 grafted on monolayer graphene nanosheets (Fe3O4/GNs) were prepared by a facile method,. The structure and conductivity of Fe3O4/GNs were further characterized by X-ray diffraction, Transmission electron microscope, Atomic Force Microscope, Raman spectroscopy and four probe techniques. The results indicated that the Fe3O4 was uniformly coated on surface of monolayer GNs with high conductivity of 88.6S/cm. Moreover, the electrode based on Fe3O4/GNs has been characterized by the cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectra. The Fe3O4/GNs electrode exhibited excellent specific capacitance of 248.5 F/g, which was higher than that reported in previous works. The improvement was attributed to high conductivity and double-layer capacitance of the GNs. The work not only demonstrates the controlled synthesis of high-quality Fe3O4/GNs at mild conditions on a large scale, but also provides a universal route for the rational design of supercapacitors with high performance.