Electrochemical Deposition and Properties of Polyaniline Films on Carbon and Precious Metal Surfaces in Perchloric Acid/ Acetonitrile

摘要

Beside the electrochemical polymerization of polyaniline (PANI) films on electrode surface, themedium of polymerization and the metal surfaces are essential to increase the yield and electricalconductivity of PANI formed. The electrochemical synthesis of films of PANI on pyrolitic graphite(PG), glassy carbon, gold and platinum electrodes in perchloric acid/acetonitrile solution (0.1 MHClO4/ACN) was investigated. Linear scan voltammograms (LSV) for these electrodes exhibitedsimilar onset potentials (Eonset = 0.89 to 0.94 V) for the oxidation of aniline into its radical cation. The-8 heterogeneous electron transfer constants at the onset potentials (ket-onset) varied as follows: Pt (7 10-1 -8 -1 cm s ) GC> Au > PG (0.6 10 cm s ). During multi-cyclic potentiodynamicelectropolymerization processes, three pairs of anodic and two pairs of cathodic growth-peaks wereobserved for Pt, GC, Au, but three pairs cathodic growth-peak for PG. All electrodes present goodstability vis-a-vis PANI. Outcomes of further studies on the resulting films, carried out with cyclicvoltammetry (CV) are discussed and the resultant PANI thin films can be used as transducer in theconstruction of sensors platform.