Polypyrrole Nanoparticles Doped with Fullerene Uniformly Distributed in the Polymeric Phase: Synthesis, Morphology, and Electrochemical Properties

Composites of polypyrrole and fullerene C 60 were prepared by the introduction of fullerene during polymerization of pyrrole initiated by the oxidation of pyrrole oligomers with C 60 . Composites were precipitated in the form of spherical particles, and their sizes ranged from 20 to 400 nm depending on the time of polymerization. Fullerene C 60 nanocrystals with approximate size of 1 nm were uniformly distributed within the polymeric material. The amount of fullerene incorporated into polypyrrole depended on the C 60 concentration in the solution used for the composite formation. An investigation of the composite using infrared spectroscopy indicated partial charge transfer between polypyrrole chains and fullerene nanocrystals. Such process was also confirmed by the theoretical investigation of electronic properties of composite. The composites were electrochemically active over a large potential window. At negative potentials, fullerene nanocrystals were reduced. In the positive potential range, polypyrrole chains were oxidized. Both processes were accompanied by complex ion transfer between supporting electrolyte solution and composite solid phase immobilized at the electrode surface.