Electrochemical property of surface modified polypyrrole film with heteropoly anions

Electrochemical preparation of polypyrrole film incorporated with heteropolymolybdate anion on glassy carbon and their electrochemical properties were studied. Cyclic voltammogram showed reversible peaks from polymer itself and from the incorporated heteropoly anion. The peak potential due to polypyrrole shifted to negative direction by about 40 mV/pH, while those of poly anionʹs peaks exhibited about −60 mV/pH. As the thickness of the film changed, the charge transport mechanism also changed and the redox peaks shifted to negative direction. The amount of incorporated anions determined by electrochemical and spectroscopic methods depended linearly on the charge passed in the polymerization process. Electrochemical quartz crystal microbalance technique revealed the polymerization occurs through nucleation and film growth steps.