Copper modified poly(3,4-ethylenedioxythiophene) part II: Potentiostatic experiments

The electrochemical reduction of copper ions is investigated at poly(3,4-ethylenedioxythiophene) (PEDT) coated electrodes by means of potentiostatic experiments, cyclic voltammetry and ESR measurements. It is established that copper deposition at low overpotentials allows stabilization of a considerable amount (up to 10%) of copper species in the polymer layer and impeding the copper crystallization process. An additional redox couple is found to appear at the PEDT voltammogram showing two different valence states of the copper/polymer related species. ESR and electrochemical measurements allow concluding that the redox couple is related to the formation of a [Cu(I)PEDT](+) complex and corresponds to the [Cu(I)PEDT](+) + e(-) <----> Cu(0)PEDT reaction. ESR spectra show that Cu atoms specifically bonded to the polymer disturb the PEDT paramagnetic system. (C) 2003 Elsevier B.V. All rights reserved.