Preparation and performance of modified electrodes based on conducting co-polymer and its composite with inorganics

Abstract

Modification of electrode matrices with conducting copolymer was attempted. The electrodes thus modified were examined for their performance in carrying out some standard electrochemical redox processes on thelf surfaces . PI electrode was modified with the films of i) conducting polymers, viz., PANI, CH3-PANI, PABA and PP Ii} conducting copolymers, viz., PANII CH3-PANI, PANI/PP, PANI/PABA iii) polymeric composites, viz" PANI/CH3-PANIISiO" PANI/PPI$I02 The film of conducting polymers, copolymers and the composites were prepared by the simple one step electrochemical means. Corresponding monomer(s), inorganics were kept III electrolytic solutions and deposited a polymeric film onl0 the PI substrates either by sweeping the polentials or by constant potential mode. The film thus grown onto the Pt surface were free-standing depending on lhe thickness of the deposit grown. The modifier matrices were characterized by a wide range of experimental techniques including UV-Vis and IR spectroscopy, d c. conductance and scanning electron microscopy. IR spectral analysis Yielded characteristic bands confirming the presence of polymeric and inorganic components. UV-Vis optical spectra of the samples showed strong absorption maxima in ultraviolet region and another band in the VISible region that are attnbutable for conductive polymeric component The electrical conductivity of the samples was measured in their compressed solid state The electrode matrices that are synthesized in this study are found to be fairly conductive and their conductiVity falls in the range of conventional semiconductors The surface morphology of the modified electrodes was examined. The matrices showed diSSimilar surface morphology from granular to fibril. The dissimilar surface morphology showed different electrode activity of the matrices. The electrode matrices thus modified were found to be electroactive both in aqueous and non-aqueous solvents The polymeric electrodes in the appropnate electrlytlc media exhibited doping-dedoping phenomenon corresponding to the polymeric oxidation-reduction processes, respectively, ThiS result indicates Ule charging-discharging capacities of modified electrodes, The electrolytic matrices were then used as modified electrode. The redox processes Fe2' --+ Fe" + e' and H20 --+ 0 + 2H' + 2e' were performed on their surfaces The modified electrodes thus prepared in this study were found to be capable of performing the redox processes effiCiently. The effects of solvent and film thickness on the performance of the modified electrodes were also investigated. The presenl study clearly revealed that conducting copolymer modified electrode could be a good replacement lor the costly noble Pt eleclrode In terms of cost, availability and ease of techniques for preparation and application in a real system.