Electro-oxidation of chlorophenols on poly(3,4-ethylenedioxythiophene)-poly(styrene sulphonate) composite electrode

The electrochemical behaviour of chlorinated phenols on Pt/poly(3,4-ethylenedioxy)thiophene (PEDOT) and on Pt/PEDOT/poly(sodium-4-styrenesulfonate) (NaPSS) electrodes has been investigated in phosphate buffer solutions. The NaPSS plays a positive role against electrode passivation, allowing further oxidation of 2-chlorophenol after the first scan. Hypotheses about the role exerted by NaPSS were made on the basis of the evidences provided by several techniques, such as cyclic voltammetry, electrochemical impedance spectroscopy, electrochemical microbalance and atomic force microscopy. Moreover, various chlorophenols show differences in their voltammetric responses depending on number and position of the chloro substituents on the aromatic ring. This suggests possible applications of the modified electrode in the analysis of chlorinated phenols mixtures.