Electrochemical impedance spectroscopy of poly(3-methylthiophene) and poly(3-octylthiophene) film electrodes

Charge transfer processes in poly-3-methylthiophene (PMT) and poly-3-octylthiophene (POT) film electrodes bathed with 0.05-0.5 M LiClO4 acetonitrile solutions were studied by cyclic voltammetry and electrochemical impedance spectroscopy. Semi-circle parameters Rct and Cdl, Warburg constant σw, effective diffusion coefficients Deff, and low-frequency capacities CLF were determined for PMT and POT films as functions of the bathing electrolyte concentration and the electrode potential. A comparison between the results of electrochemical studies of PMT and POT modified electrodes is performed in the paper.