Synthesis of novel graphene oxide/pristine graphene/polyaniline ternary composites and application to supercapacitor

A new ternary composite using graphene oxide (GO), pristine graphene (PG), and aniline as starting materials is designed and successfully prepared by an easy two-step method: first GO sheets are 'patched' with small PG sheets by simply mixing homogeneous GO/H2O and PG/DMSO dispersions to form GO/PG nanosheets, followed by coating polyaniline (PANI) via an in situ chemical polymerization process. The morphology and electronic structure of thus obtained GO/PG/PANI (GPP) ternary composites were characterized using SEM, TEM, XPS and Raman spectroscopy. The GPP exhibits higher specific capacitance than those of individual components or binary composites and better cycling stability. The specific capacitance of GPP is as high as 793.7 F g−1 measured by galvanostatic charge-discharge method at a current density of 1.0 A g−1 using a three-electrode system, and still keeps as high as 564.2 F g−1 at a current density of 2.0 A g−1 in a sandwich type symmetric supercapacitor with the electrode material even scaling-up 20 times. The specific capacitance of the composites retains approximately 80% after 1000 cycles at a scan rate of 100 mV s−1.