Nanocomposite films of polyaniline/graphene quantum dots and its supercapacitor properties

In the present study, at first S-, N-doped graphene quantum dots (GQDs) was synthesised by using citric acid as C source and thiourea as N, S source via facile hydrothermal synthesis route. Then, composite films of polyaniline-GQD (PANI-GQD) were prepared by in-situ electrochemical polymerisation of an aniline solution containing GQD. The different concentrations of GQD were utilised to improve the electrochemical performances. Formation of PANI and PANI-GQD films was confirmed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transformed infra-red analysis, and the electrochemical performances of the composites were evaluated by cyclic voltammetry (CV). The results of electron microscope images showed that PANI were not only coated on the surface but also intercalated into GQD sheets. Application of the prepared samples has been evaluated as supercapacitor material in 0.5 M H 2 SO 4 solution using the CV technique. The specific capacitance of PANI-GQD composite films was higher than that obtained for pure PANI films.