Polyaniline-graphene composites with a three-dimensional array-based nanostructure for high-performance supercapacitors

The ordered three-dimensional arrays conjugative polyaniline–graphene composites were fabricated through in-situ chemical oxidative polymerization of aniline in the presence of amino-functionalized graphene sheets (AFG), in which polyaniline (PANI) polymerization is initiated by those amino groups on graphene. Therefore, the resulting PANI nanorod arrays are integrated into a large conjugative frame based on chemical covalent bond incorporation. The structure and properties of these resulting composites were characterized and evaluated by combining Fourier transform infrared spectroscopy, Ultraviolet–visible absorption spectroscopy, Raman spectroscope, X-ray diffraction spectroscopy analyses and electrochemical techniques. Morphology was studied by scanning electron microscopy. It was found that the density and size of ordered PANI nanorod arrays can be manipulated by simply varying the amount of AFG. Such resultant composite exhibits high special capacitance, together with low electrical resistance and excellent cycling stability attributed to conjugative covalent bonds and ordered PANI nanorod arrays. Meanwhile, a new time-dependent heterogeneous nucleation mechanism was proposed and investigated in detail.