Electrochemical properties of poly(3,4-ethylenedioxythiophene) grown on Pt(111) in imidazolium ionic liquids

Abstract

Poly(3,4-ethylenedioxythiophene) (PEDOT) was galvanostatically synthesized and studied on a Pt(111) electrode in the following ionic liquids: 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][NTf₂]), 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide ([Emmim][NTf₂]), 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([Bmim][OTf]) and 1-butyl-2,3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmmim][NTf₂]) by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The thin films prepared with this method and cycled in these ionic liquids show high n-doping currents and high rates of ion exchange during redox switching compared to those obtained in molecular solvents.