Preparation and characterization of polypyrrole/graphene nanocomposite films and their electrochemical performance

Abstract

A one-step electrochemical process had been employed to synthesize nanocomposite films of polypyrrole/graphene (PPy/GR) by electrochemical polymerisation on indium tin oxide (ITO) from an aqueous solution containing pyrrole monomer, graphene oxide (GO) nanosheets and sodium p-toluenesulfonate (NapTS). The X-ray diffraction (XRD) patterns showed that the typical peak of GO at 9.9o was missing from the nanocomposite's diffraction pattern, suggesting that the GO had been stripped off of its oxygenous groups after the reaction. We postulated that a nanocomposite film was produced through a layer-by-layer deposition based on field emission scanning electron microscope (FESEM) images. The Raman spectroscopy profiles exhibited that the D/G intensity ratio (ID/IG) of PPy was not altered by the inclusion of GO due to the low concentration of the material used. However, the concentration was sufficient to increase the specific capacitance of the nanocomposite by 20 times compared to that of pure PPy, reflecting a synergistic effect between PPy and GR, as analysed by a threeelectrode electrochemical cell. The electrochemical performance of the nanocomposites was affected by varying the deposition parameters such as concentrations of pyrrole and GO, scan rate, deposition time and deposition potential.

Effect of graphene oxide on the structural and electrochemical behavior of polypyrrole deposited on cotton fabric

“…This improved electrochemical feature may have immense importance in storing charge in this composite and also GO, which is known for its large surface area. Increase in the surface area of Ppy/GO/Cotton, which provided more electrode/electrolyte interface areas, led to better accessibility of electrolyte ions [28,40]. The specific capacitance, C, of Ppy/ GO/Cotton and Ppy/Cotton, is calculated by the following equation:…”

Dual functional reduced graphene oxide as photoanode and counter electrode in dye-sensitized solar cells and its exceptional efficiency enhancement

“…The large amount of pTS dopant used during the electrodeposition process dictated that the formation of Ppy was in the form of domains or network structures on the rGO sheets [46]. The distinguishable components of Ppy and rGO are in contrast to the previously reported Ppy/graphene composite that employed a minimal amount of pTS, in which the composite comprised a thick polymeric Ppy matrix arranged in a layer-by-layer configuration with the graphene sheets [47]. Moreover, the incorporation of a large-size dopant anion such as pTS into the Ppy-rGO film during electropolymerization resulted in a highly porous film [48].…”

In-situ polymerization of polyaniline on the surface of graphene oxide for high electrochemical capacitance

“…Secondly, the polymers usually showed poor cyclic stability because the polymers are brittle and weak in mechanical strengths [16]. Coupling conducting polymers to a carbon-based materials [12,14,[17][18][19][20] has been shown to be an effective approach to improve the cycling stability. For example, vertically aligned polyaniline nanowhiskers have been successfully synthesized on the external surface of mesoporous carbon through a chemical oxidative polymerization, which delivered a large specific capacitance and good capacitance retention [18].…”