Polypyrrole Nanofibers with Extended 1D Hierarchical Structure

Abstract

A two‐step electrochemical synthesis of polypyrrole nanofibers with a fractal‐like surface structure is described. The bilayer structure of polypyrrole on a Pt substrate provided protection of the polymer against overoxidation. The polypyrrole bilayer is electronically conductive. Specific charge‐transport properties originated from the primary counter ions used in the two‐step electrosynthesis. When the outer layer of polypyrrole was involved in cation exchange during redox switching, the inner layer of anion exchanging polypyrrole was set at its conductive oxidized state, thus providing a stable reversible redox activity of the former. The growth dimensionality of the outer layer (1D or 2D) depended on the concentration of the anionic surfactant in the polymerization solution.

Overoxidation of Intrinsically Conducting Polymers

“…PPy nanofibers electrodeposited in a two-step process turned out to be more overoxidation-resistant. Different counter anions in the core and the outer layer suppressed removal of the anions from the core, which kept the core electronically conductive and hindered overoxidation of the shell [220].…”