Preparation and Electrochemical Properties of Functionalized Graphene/Polyaniline Composite Electrode Materials

Octadecylamine functionalized graphene (ODA-G) was synthesized by the grafting of graphene oxide (GO) with ODA followed by reduction with hydrazine hydrate. Subsequently, ODA-G/polyaniline (PANI) composites were prepared using a facile solvent-blending procedure. ODA-G and ODA-G/PANI composites were characterized by Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman spectroscopy, and transmission electron microscopy (TEM). The electrochemical properties of the composites were measured based on cyclic voltammetry (CV), galvanostatic charge/discharge, and ac impedance spectroscopy. The results show that ODA-G as a support material provides additional electron transfer paths, as well as active sites, for the electrochemical redox reaction of PANI, which helps to increase its pseudocapacitance. A specific capacitance of 782 F.g(-1) is obtained for 2%(w)ODA-G/PANI at a current density of 1.0 A.g(-1), compared with 426 F.g(-1) for PANI. Furthermore, ODA-G/PANI exhibits better stability than PANI.