Structure and I_2/I- redox catalytic behaviour of PEDOT-PSS films electropolymerized in aqueous medium: Implications for convenient counter electrodes in DSSC

摘要

The present paper focuses on the impact of different electro-synthesis processes, used to produce poly(3,4-ethylenedioxythiophene)- poly(styrenesulfonate) (PEDOT-PSS) systems in aqueous medium, on the polymer backbone and its electro-catalytic activity. FE-SEM and micro-Raman spectroscopy were used to analyze the samples obtained by varying the conditions of the electro-polymerization processes. The I_2/I- redox behaviour of various PEDOT-PSS layers has been comparatively examined in relation to the surface morphology and structural characteristics of the polymer. A response similar to that of a conventional Pt electrode has been revealed for the films produced by chronoamperometric technique. The study has demonstrated that the polymer structure plays an important role in the electro-activity, providing a possibility to improve the redox performance of PEDOT-PSS films by a proper choice of the synthesis methods. Moreover, the use of aqueous solution as a reaction medium can be welcomed as a sustainable chemistry way involving the use of environmentally friendly chemicals.