Fabrication of graphene oxide/polypyrrole nanowire composite for high performance supercapacitor electrodes

Graphene oxide/polypyrrole nanowire composite material (GO/PPy) is synthesized using an in situ chemical polymerization method. The field-emission scanning electron microscope (FE-SEM) and transmission electron microscopy (TEM) results demonstrate that the PPy nanowires with 40 nm in diameter are uniformly dispersed on the surface of GO nanosheets, which greatly increases the surface area of the material and the charge transfer reaction. This two-dimensional structure exhibits better electrochemical performance than the pure individual components. According to the galvanostatic charge/discharge analysis, the GO/PPy composite has a good supercapacitive performance with a specific capacitance of 728 F g(-1) at a discharge current density of 0.5 A g(-1), higher than that of PPy nanowires (251 F g(-1)). At a discharge current density of 2.5 A g(-1), the GO/PPy composite also has a high specific capacitance of 675 F g(-1). Significantly, the GO/PPy electrode shows excellent cycling stability (7% capacity loss after 1000 cycles) due to the GO layer releasing the intrinsic differential strain of PPy chains during long-term charge/discharge cycles. (C) 2013 Elsevier B.V. All rights reserved.