Analytical X-ray photoelectron spectroscopic investigation of the modification of polybithiophene (pbT) under electrochemical cycling

Abstract

Electrochemically synthesised polybithiophene (pbT) films have been analysed by XPS, as grown and after galvanostatic cycling, to test their chemical stability under use and to obtain more information about the doping–undoping process.

It has been shown that working conditions can heavily influence the behaviour of the conducting polymer under cycling. In particular, a water content higher than 0.03% v/v in the acetonitrile solvent can promote irreversible modification of the surface chemistry of pbT. Surprisingly, the dopant ClO^–₄ anions can be reduced on the polymer-modified platinum electrode and the reduction products react with the pbT backbone.