Electron transfer at conducting polymer film electrodes: Mechanism and kinetics of ferrocene oxidation at poly(3-octylthiophene)

Johan Bobacka, M Grzeszczuk, Ari Ivaska

Tutkimustuotos: LehtiartikkeliArtikkeliTieteellinenvertaisarvioitu

38 Sitaatiot (Scopus)

Abstrakti

Oxidation of ferrocene at a poly(3-octylthiophene) (POT) film electrode has been investigated by using cyclic voltammetry, rotating disc electrode voltammetry and electrochemical impedance spectroscopy. The POT film electrode wats prepared by galvanostatic electropolymerization of 3-octylthiophene on a rotating Pt disc electrode. In the medium used i.e. 0.1 M LiBF4 + propylene carbonate, the formal redox potentials of ferrocene and POT are 0.4 and 1.1 V vs. Ag/AgCl respectively. This makes it possible to study the oxidation of ferrocene at both undoped (semiconducting) POT and at doped (electronically conducting) POT. The voltammetric data show that the oxidation of ferrocene is kinetically controlled at undoped or lightly doped POT while ferrocene is oxidized at a diffusion limited rate at highly doped POT. Impedance data on the POT film electrode in solutions containing different concentrations of supporting electrolyte and ferrocene indicate that the ferrocene oxidation occurs in parallel with the doping process, resulting in a competition between ferrocene and doping ions for the available 'sites' at the polymer/solution interface. The kinetics of electron transfer at the polymer/solution interface are discussed based on the Butler-Volmer formulation of electrode kinetics. (C) 1997 Elsevier Science S.A.
AlkuperäiskieliEi tiedossa
Sivut63–69
Sivumäärä7
JulkaisuJournal of Electroanalytical Chemistry and Interfacial Electrochemistry
Vuosikerta427
Numero1-2
DOI - pysyväislinkit
TilaJulkaistu - 1997
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

Keywords

  • poly(3-octylthiophene) film
  • electron transfer

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