Electrochemical performance of a graphene-polypyrrole nanocomposite as a supercapacitor electrode.

A unique nanoarchitecture has been established involving polypyrrole (PPy) and graphene nanosheets by in situ polymerization. The structural aspect of the nanocomposite has been determined by Raman spectroscopy. Atomic force microscopy reveals that the thickness of the synthesized graphene is ∼ 2 nm. The dispersion of the nanometer-sized PPy has been demonstrated through transmission electron microscopy and the electrochemical performance of the nanocomposite has been illustrated by cyclic voltammetry measurements. Graphene nanosheet serves as a support material for the electrochemical utilization of PPy and also provides the path for electron transfer. The specific capacitance value of the nanocomposite has been determined to be 267 F g(-1) at a scan rate of 100 mV s(-1) compared to 137 mV s(-1) for PPy, suggesting the possible use of the nanocomposite as a supercapacitor electrode. After 500 cycles, only 10% decrease in specific capacitance as compared to initial value justifies the improved electrochemical cyclic stability of the nanocomposite.