Electrochemical impedance spectroscopy (EIS) leads to information on electrochemical kinetics mechanisms, but cannot identify the nature of species adsorbed at the electrode surface. Raman spectroscopy is a powerful technique for structural investigations; it can provide the information needed on the molecular level, which is missing in the measure of EIS. The purpose of this work was to couple dynamically these two techniques. This new technique -Spectro-electrochemical Raman-impedancewas applied to the investigation of a conducting polymer film. The principle of the technique consists in analyzing the spectrum emitted by the interface and then to convert the intensity of the selected bands into a voltage. Several transfer functions ΔV/ΔI, ΔRaman/ΔV, Δ Raman/ΔI; are recorded simultaneously. The first results of this technique applied to the study of a polyaniline thin film show that the acid base equilibrium inside the polymer has to be taken into account on the basis of a kinetics mechanism involving two redox reactions and a chemical reaction.
