INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
A molecular theory of chemically modified electrodes with self-assembled redox polyelectrolye thin films: Reversible cyclic voltammetry
TAGLIAZUCCHI, MARIO; SZLEIFER, IGAL; CALVO, ERNESTO J.
Año: 2008 vol. 53 p. 6740 - 6740
A molecular theory of chemically modified electrodes is applied to study redox polyelectroyte modified electrodes. The molecular approachexplicitly includes the size, shape, charge distribution, and conformations of all of the molecular species in the system as well as the chemicalequilibria (redox and acid-base) and intermolecular interactions. An osmium pyridinebipyridine complex covalently bound to poly(allyl-amine)backbone (PAH-Os) adsorbed onto mercapto-propane sulfonate (MPS) thiolated gold electrode is described. The potential and electrolyte composition dependent redox and nonredox capacitance can be calculated with the molecular theory in very good agreement with voltammetric experiments under reversible conditions without the use of freely adjustable parameter. Unlike existing phenomenological models the theory links the electrochemical behavior with the structure of the polymer layer. The theory predicts a highly inhomogeneous distribution of acid-base and redox states that strongly couples with the spatial arrangement of the molecular species in the nanometric redox film.