A UV-Visible/Raman spectroelectrochemical study of the stability of poly(3,4-ethylendioxythiophene) films

Poly(3,4-ethylendioxythiophene) films were electropolymerized in aqueous medium without using any surfactant, on glassy carbon electrodes. UV/Vis and Raman spectroelectrochemical techniques were used to analyze the degradation of the polymer film occurring at different pH values. Spectroelectrochemistry has proven to be a very useful analytical tool for this purpose, thanks to its ability to provide information not only about the extent of degradation, but also about mechanistic aspects of the process. From our results we extracted important information about the main factors that play a role in the degradation, in particular about the influence of repetitive doping and de-doping cycles and of photo-induced processes, as a function of the characteristics of the solution, i.e. of pH.