ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 40, Number 7
JKCSEZ 40(7)
February 20, 1996 

Although a polypyrrole shows better electrical conductivity, 100∼400 Ω^-1cm^-1, than other organic conducting polymers, its electrical conductivity will be worsen in the presence of the oxygen due to its easy oxidation. On the other hand, polythiophene shows better stability in the air while its electrcal conductivity is poor compared to the polypyrrole. We succeed to develope the mixed polymer electrode that is stable in the air and shows a good redox characteristics. The mixed polymer electrode has been prepared by the electrical polymerization of polypyrrole on the Pt electrode as 1.70 Ccm^-2 and then coating with polythiophene as 0.34 Ccm^-2. The polymerization rate of polythiophene was 3.89×10^-8 at the bare Pt electrode and 6.07×10^-8cms-1 at the mixed polymer electrode. And the standard rate constants of each electrode were 5.16×10^-6 and 3.94×10^-4 cms-1 respectively. Also, the electrocatalytic rate of the polypyrrole polymer electrode was 3.45×10^-3cm³mol^-1s^-1. We found the immobilized layer at the modified electrode acted as an electrocatalyst. Finally, this polymerization process at the Pt electrode was the electron transfer controlled, but that the mixed polymer electrode was the diffusion and charge transfer controlled.