Electrochemical synthesis of polyaniline-exfoliated graphene composite films and their capacitance properties

In this work, the graphene was synthesized by electrochemical exfoliation method, which was used to prepare the polyaniline-graphene composite film (PANI-GR) onto fluorine doped tin oxide (FTO) electrode by chronoamperometry technic at monomer oxidation potential 0.8 V vs. SCE. During the electropolymerization, the incorporation of the synthetized graphene into polyaniline matrix was assured by agitation of the electrolyte (10⁻² M Ani/1 M H₂SO₄) containing different mass of graphene (1, 2 and 3 mg). By taking the advantages of the high conductivity of GR and the pseudocapacitance of PANI, the FTO/PANI-GR composite film was taken as an example for the application to the supercapacitor electrode materials. The morphology and structure of FTO/PANI and FTO/PANI-GR were characterized by different technics SEM, XRD, FTIR, Raman spectroscopy and UV–visible spectroscopy. The electrochemical performance was evaluated by cyclic voltammetry, galvanostatic charge-discharge tests and electrochemical impedance spectroscopy (EIS). The obtained specific capacitance for the PANI material alone is about 176.29 F g⁻¹ this value was increased up to 305.57 F g⁻¹ for the composite film PANI-GR 3 mg at 5 mV s⁻¹.