Application of the A.C. Admittance Technique to Double Layer Studies on Polycrystalline Gold Electrodes
Abstract
A detailed examination of the dependence of the a.c. admittance of a cell containing a polycrystalline gold electrode has been made in the double layer region as a function of d.c. potential, a.c. frequency and electrode history. It is shown that the interfacial impedance of a gold electrode with a carefully prepared surface can be treated under these circumstances as a constant phase element when it is in contact with an aqueous solution containing 0.05 M KClO4. Analysis of the frequency dependence of the cell impedance gives the surface inhomogeneity parameter n which tums out to be very close to unity. Although the electrode surface is only slightly inhomogeneous on a microscopic scale, a very large frequency dispersion of the impedance is observed experimentally. A method of estimating the true specific capacity of the electrode is presented, and conditions for carrying out the experiments in a reproducible manner discussed. double layer at gold/solution interface, a.c. admittance techniques, constant phase element model.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 24, 1992
- Accession Number
- ADA247108
Entities
People
- Arthur J. Motheo
- Colby A. Foss Jr.
- William Ronald Fawcett
- Zuzana Kovacova
Organizations
- University of California, Davis