Rotating Disc Voltammetry at Polypyrrole Modified Electrodes.
Abstract
The nature and uniformity of insitu electrogenerated Polypyrrole Films (PPF's) are strongly influenced by the nature of the electrode, deposition potential and uniformity of the current density at the electron surface. A uniform current density during deposition is absolutely essential. In general, it appears that deposition first occurs at isolated active sites followed by radial growth out from these sites. This phenomonae appears to occur at all materials studied but seems more pronounced on SnO2 coated glass than on metal surfaces. The optimal electropolymerization potential found in this study (+1000 mV) is well into the oxidation wave of pyrrole. In our experience the use of potential pulses rather than a steady DC potential does not seem to improve PPF homogeneity, in contrast to the results obtained by other workers. One important question about PPF electrodes relates the mechanism of the transport of species to the electrochemically active surface. An interesting possibility is that an ionic gating mechanism is evolved and that electrochemically neutral PPF would be a porous membrane, with the electronically conducting polymer chains increasing the area of the electrode. This possibility was investigated using Rotating Ring Disk (RD) techniques.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1984
- Accession Number
- ADA159623
Entities
Organizations
- University of Cincinnati