An impedance study about the effect of pH on the electron transport rate at poly(o-aminophenol) film electrodes

R. TUCCERI

Current Physical Chemistry

BENTHAM SCIENCE PUBLISHERS LTD

Lugar: Sharjah; Año: 2014 vol. 4 p. 232 - 237

1877-9468

Impedance measurements on poly(o-aminophenol) (POAP) film electrodes in contact with solutions of different pH were carried out. Impedance spectra were interpreted in terms of the modified electron hopping model described in F.J. Rodríguez Nieto, R. Tucceri, J. Electroanal. Chem. 416 (1996) 1. An increase of the metal/POAP interfacial resistance with the increase of pH was obtained. With regard to the bulk charge-transport process, a decrease of the electron diffusion coefficient with the increase of pH was extracted from the fitting procedure. The change of the charge-transport and charge-transfer parameters with the increase of pH was attributed to an increase in electron hopping distance between adjacent redox sites at POAP films. Impedance results seem to be in agreement with potentiodynamic surface resistance measurements carried out in R. Tucceri, J. Electroanal. Chem., 543 (2003) 61-71.