Template Electrochemical Growth of Polypyrrole and Gold-Polypyrrole-Gold Nanowire Arrays

Abstract

In this paper, we report on the synthesis of polypyrrole (PPy) and hybrid (Au-PPy-Au) nanowire arrays of controlled dimension by an all electrochemical template method. PPy nanowires with an average diameter of only 38-160 nm were obtained by electropolymerization in well-defined conditions within the pores of homemade polycarbonate membranes. Characterization by scanning and transmission electron microscopies (SEM and TEM) revealed that the morphology (nanotubes or nanowires) of the resulting PPy nanostructures strongly depended on the electropolymerization conditions. Possible mechanisms responsible for the growth of nanowires vs. nanotubes are discussed. We also describe here a gold electroplating strategy using a homemade cyanide-free bath that was used to prepare high-quality Au nanowires with an inner PPy nanojunction. These Au-electroactive polymer-Au segmented nanowires are promising materials for use in molecular nanoelectronics.