Electrochemistry and Characterization of Conducting Poly(3-methylthiophene) Electrodes Containing Ferrocene Moieties

Abstract

Abstract Ferrocenium hexafluorophosphate was used as the supporting electrolyte during the electropolymerization of poly(3-methylthiophene) and poly(1-methylpyrrole). The electrochemical behavior of the resulting polymer electrode indicated the incorporation of the ferrocenium moiety in the polymer film. The appearance and the magnitudes of the voltammetric anodic and cathodic current peaks of the ferrocenium/ferrocenium+ couples were influenced by: (I) the method of ferrocene incorporation into the polymer film, (ii) the concentration of both the ferrocenium and the supporting electrolyte used during the polymer deposition, (iii) the thickness of the polymer film, and (iv) the type of electrolyte used during the polymer film electrochemical characterization. FTIR experiments were performed on polymer films containing the ferrocenecarbaldehyde. The results were compared to the spectrum of ferrocene-free film; the comparison indicated the incorporation of the ferrocene moiety within the polymer film. The structural aspects of the polymer films were studied using XPS experiments, which indicated the presence of iron for films containing ferrocenium. The morphological aspects of the films were studied by SEM technique which indicated that “ferrocenium-free” film morphologies are similar to those of “ferrocenium-containing” films. A model for the charge transfer within the polymer film is described. The method described in this work resulted in a stable ferrocenium-bound to the polymeric film.