APPLICATION OF ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY (EIS) TO STUDY OF PHENOLIC FILMS

This paper describes the phenol electrochemical oxidation that occurs with formation of phenolic films on the platinum electrode by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. Both cyclic voltammetry and impedance studies were performed at room temperature, using a GAMRY PC3 potentiostat. The impedance data were recorded in a frequency range from 0.01 Hz to 100 kHz, with a.c. amplitude of 5 mV. The capacitance and resistance curves were recorded at various frequencies, corresponding to the three regions from Nyquist plot, at high frequency (90kHz), where a kinetic stage controls the reaction, at small frequency (100Hz), where a diffusion control is present and at 2 kHz frequency for a mixed control.