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The reduction of oxygen on iron(II) oxide/poly(3,4-ethylenedioxythiophene) composite thin film electrodes

journal contribution
posted on 01.02.2015, 00:00 authored by Robert KerrRobert Kerr, Cristina Pozo-GonzaloCristina Pozo-Gonzalo, Maria ForsythMaria Forsyth, B Winther-Jensen
© 2014 Elsevier Ltd. All rights reserved. Conducting polymers (CPs) are currently being investigated for use in many applications owing to their abilities to catalyze a wide range of electrochemical reactions and act as an effective electrode support for various inorganic and organic electrocatalyst materials. Here, we have found that the deposition of poly(3,4-ethylenedioxythiophene) (PEDOT) through the use of an established base-inhibited chemical vapor-phase polymerization (VPP) procedure using an iron(III) tosylate oxidant results in the co-deposition of electrocatalytic iron(II) oxide species within the film. The presence of these species accounts for the 2-electron reduction of hydrogen peroxide that occurs on these electrodes during the series 4-electron oxygen reduction reaction. Furthermore, this realization leads to the possibility of fabricating thin film inorganic/CP composites of various compositions through careful choice of oxidant in a facile, one-step process. A combination of in situ Raman (487.77 nm laser) and in situ UV-Vis spectroscopy was used to probe the oxidation state of PEDOT in the thin film composite electrodes while reducing oxygen in alkaline conditions. These measurements show that the 2-electron electroreduction of hydrogen peroxide (or HO2 -) occurs only on the iron(II) oxide species in a reaction that is facilitated by an effective electron transfer from the delocalized electron orbitals of the PEDOT matrix. This approach could potentially be used in situ to monitor the electrocatalyst/electrode interface quality of conducting polymer-supported electrocatalysts.

History

Journal

Electrochimica acta

Volume

154

Pagination

142 - 148

Publisher

Elsevier

Location

Amsterdam, The Netherlands

ISSN

0013-4686

Language

eng

Publication classification

C Journal article; C1 Refereed article in a scholarly journal

Copyright notice

2015, Elsevier