Preparation and electrochemical properties of modified electrodes with Keggin-type silicotungstates and PEDOT

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 660; no. 1; pp. 50 - 56
• Main Authors: Fernandes, Diana M., Brett, Christopher M.A., Cavaleiro, Ana M.V.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.09.2011; Elsevier
• Subjects: aqueous solutions; carbon; Chemistry; dielectric spectroscopy; Electrochemical behaviour; Electrochemistry; electrodes; Electrodes: preparations and properties; Electropolymerisation; Exact sciences and technology; General and physical chemistry; Keggin-type polyoxotungstates; Other electrodes; PEDOT; polymerization; polymers; Polyoxometalates; Silicotungstates; Silicotungstates; Polyoxometalates; PEDOT; Electropolymerisation; Electrochemical behaviour; Keggin-type polyoxotungstates; Heteropolysalt; Electrochemical polymerization; Carbon; Electrochemical characteristic; Electrodes; Conducting polymers; Cyclic voltammetry; Thiophene derivative polymer; Preparation; Electrochemical reaction; Glassy state; Modified material; Electrochemical impedance spectroscopy
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2011.06.004

► Polyoxometalate-doped PEDOT modified electrodes were prepared by electrochemical polymerization. ► Fe and Co substituted Keggin-type polyoxotungstates were immobilized on the electrodes. ► The POM-doped PEDOT modified electrodes presented high stability. ► Cyclic voltammetry of the films showed redox processes occurring at W, Fe and Co. ► EIS study showed the effect of the introduction of the transition metal in the silicotungstate. Hybrid organic/inorganic films composed of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT), with Keggin type polyoxotungstates [SiW12O40]4−, [SiW11O39]8−, [SiW11FeIII(H2O)O39]5− or [SiW11CoII(H2O)O39]6− were synthesized by electrochemical polymerization in aqueous solution on the surface of glassy carbon electrodes. Cyclic voltammetry showed that the electrochemical behaviour of the polyoxometalates in the films was very similar to those in solution, and gave evidence of high electrochemical stability. Electrochemical impedance spectroscopy revealed that the charge transfer resistance increased with increasing pH and with more negative potentials. These modified electrodes were found to be very stable and could be used for at least 1month without significant alterations.