Redox Behavior of Polypyrrole Films in Different Solvents

Abstract

Abstract The redox behavior of polypyrrole (PPy) films has been examined by means of cyclic voltammetry and SEM/EDS. PPy was galvanostatically prepared in acetonitrile (AN) containing tetrabutylammonium dodecylsulfate (TBADS) as an electrolyte. Charge compensation mechanism of PPy films which incorporate dodecylsulfate (DS) ions was greatly influenced by the solvents or electrolyte used in the redox reaction. When the PPy was switched between -0.8 V and 0.5 V in the TBADS/AN solution, bulky DS ions were participated in the redox reaction of the swollen PPy film. In the aqueous solution containing NaDS, on the other hand, Na cations worked as main charge-compensating ions because DS anions with long alkyl chains were trapped in the contracted PPy and difficult to move during the switching process. However, DS ions in the TBADS/water solution should be the compensating ions to show higher oxidation potentials. When the free-standing films were reduced for 24 hours at -0.8 V against an Ag/AgCl reference elec...