Vanadium oxide assisted synthesis of polyaniline nanoarrays on graphene oxide sheets and its application in supercapacitors

In this work, a novel approach was developed for creation of polyaniline (PANI) nanoarrays on graphene oxide (GO) sheets. In-situ polymerizations of aniline monomer, in the presence of two oxidants, were used. For this means, firstly, nanocones of PANI were created on GO sheets by using V2O5 as oxidant, followed by further growth of these structures by using ammonium persulfate (APS) as oxidant to achieve unique nanoarrays of PANI on GO sheets (PANI/GO-V-APS nanocomposite). For comparison, other nanocomposites were also prepared by separately application of APS and V2O5 as oxidants. Some characterization techniques including XRD, FT-IR, Raman, FE-SEM, and TGA were used to elucidate the structure of nanocomposites. The results revealed well formed nanoarrays of PANI on GO for nanocomposites, which synthesized by sequential application of oxidants. Furthermore, PANI/GO nanocomposite prepared by sequential approach showed the highest current density among all the nanocomposites. In addition, the charge-discharge experiments demonstrated that the specific capacitance of the PANI/GO-V-APS composite was 712 F g(-1) at the current density of 0.5 A g(-1) in 1 M H2SO4 solution, which was significantly higher than that of two other nanocomposites. Moreover, the composite displayed good cycle stability retaining 83% of its original specific capacitance after 6000 charge-discharge cycles. Beside these achievements, the EIS results proved that the capacitance of PANI/GO-V-APS nanocomposite was higher than other nanocomposites.