Investigation of charging, transport and reaction processes in Ti/IrO/sub 2/-Nb/sub 2/O/sub 5/ anodes prepared by a sol-gel derived method

Abstract

In the present work we investigate the charging, transport and reaction processes in Ti/IrO/sub 2/-Nb/sub 2/O/sub 5/ using electrochemical impedance spectroscopy (EIS). The electrochemical impedance response of the electrodes was modeled using the theory of porous electrodes. The spectra for the electrodes in a wide range of composition have shown the typical behavior of a porous structure, exhibiting a straight line with slope of 45/spl deg/ at high frequency and a CPE in the low frequency domain, depending on the applied dc-potential. The spectra were adjusted to the model and the impedance parameters were extracted and analyzed as function of the electrode composition and applied dc voltage.