Novel preparation of hydrophilic graphene/graphene oxide nanosheets for supercapacitor electrode

This work presents the preparation of hydrophilic graphene/graphene oxide nanosheets by liquid-shear-exfoliation using graphite oxide as an additive. And the as-prepared graphene/graphene oxide nanosheets are applied to the synthesis of the three-dimensional graphene/polyaniline composites that are applied as supercapacitor electrodes directly. A variety of influencing factors on the concentration of graphene/graphene oxide nanosheets are systematically explored, indicating that this method is easy to scale up. A series of characterizations prove that the graphene can be successfully exfoliated with the help of graphite oxide, and graphene can effectively combine with graphene oxide. The composites exhibit better electrochemical properties (gravimetric capacitance of 483 F g−1 at 1 A g−1) than materials built with the mixture of graphene, graphene oxide, and polyaniline as precursors. In addition, the symmetric supercapacitor which is assembled from the composites demonstrates a high energy density of 17.9 Wh kg−1 at a power density of 500 W kg−1. These results show that graphene/graphene oxide nanosheets have a good application in supercapacitors.