EIS Study of Poly 3,4-Ethylenedioxythiophene

Typical impedance spectra of the Pt PEDOT(KCI) electrode in 0.1, 0.025, and 0.00625 M KCl are dominated by a 90 capacitive line, which extends down to very low frequencies (0.01 Hz) for thick films ofPEDOT.203 

At the lowest frequencies studied (down to 0.01 Hz), the impedance plots deviate from the 90° line, forming the beginning of a semicircle, for a thin PEDOT film (polymerization charge = 1 mC). The appearance of the low-frequency semicircle in the impedance plots observed in the presence of oxygen is in agreement with the theory, which takes into account both ion and electron transfer between the polymer and the solution. 

Partially oxidized graphene flakes (po-Gr) were obtained from graphite electrode by an electrochemical exfoliation method. As-produced po-Gr flakes were dispersed in water with the assistance of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT-PSS).2 4 

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