Graphene/polypyrrole nanofiber prepared by simple one step green method for electrochemical supercapacitors

In this work a simple green method has been developed to synthesize polypyrrole/graphene nanofiber (green-ppy/G) based on graphene oxide and pyrrole direct interaction without using reducing agent, oxidative agent, surfactant and organic solvent. The synthesis procedure was simple, inexpensive and ecofriendly. Morphology and structure of the synthesized nanocomposites was discussed by XRD, SEM, TEM and CV techniques. XRD pattern revealed that the resulting polypyrrole was not amorphous and the graphene oxide sheets improved the crystalline structure of the obtained polymer. SEM image looked like a very thin layer drawn over the underlay and implied that the ppy has been covered on the surface of grapheme sheets. In the TEM image of the nano composite the nanofibers of ppy attached to the graphene layer were clearly seen. A maximum capacitance value of 480 Fg(-1) was obtained by cyclic voltammetry at scan rate 5 mV s(-1) in 1 M NaCl solution. At the current density of 100 mA cm(-2) even after 1000 charge-discharge cycles on the green-ppy/G-PGE 94% of the initial capacitance remained. According to the noticeable electrochemical properties, the green-ppy/G-PGE has a very high potential for the design of supercapacitors.