Graphene oxide/polyaniline nanotube composites synthesized in alkaline aqueous solution

• Graphene oxide (GO)/polyaniline (PANI) nanotube composites were prepared by in situ polymerization in alkaline aqueous solution, in which GO can be considered as a stabilizer.
• High specific capacitance (277 F g−1 at 1.0 A g−1) and good cycling stability (less than 6% decrease after 1000 cycles) were achieved.
• The GO/PANI nanotube composites possessed an excellent catalytic activity toward the redox reaction of H2O2, with a detection limit of 8.6 μM.

We report a facile strategy to synthesize graphene oxide/polyaniline (GO/PANI) nanotube composites by using in situ polymerization in an alkaline solution. Because the carboxyl groups on GO surface possess reactivity with both aniline and alkali, which can stabilize the aniline droplets, the size of obtained GO/PANI nanotube aggregates were reduced compared to that of pure PANI. The doping effect between PANI nanotube and GO is characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectra, and the electrochemical performances of the nanotube composites are evaluated by galvanostatic charge–discharge. As the oxygen-containing groups on the edge of GO can serve as an excellent electrolytic accessible surface for redox-active PANI nanotubes, the maximum specific capacitance of 277 F g−1 at 1.0 A g−1 is observed at the GO/PANI electrodes. Moreover, the GO/PANI nanotube composite shows excellent long-term cyclic stability (less than 6% decrease in specific capacitance after 1000 cycles at a current density of 1.0 A g−1), because the swelling and shrinkage of PANI during doping–dedoping processes can be efficiently restrained by the high flexible GO sheets intercalated within the system. In addition, the GO/PANI nanotube composites possessed a catalytic activity toward the redox reaction of H2O2 with a detection limit of 8.6 μM, indicating a positive synergistic effect for the improvement of electrochemical performance.

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