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Capacitance of the gold electrode in 0.5 M H2SO4 solution: a.c. impedance studies
- Source :
- Journal of Electroanalytical Chemistry. 388:69-79
- Publication Year :
- 1995
- Publisher :
- Elsevier BV, 1995.
-
Abstract
- Impedance spectroscopy was used to measure the properties of the gold electrode in 0.5 M H 2 SO 4 solution in the double-layer region (−0.25 to 1.05 V vs. sodium chloride saturated calomel electrode (SSCE)) and the region of oxide monolayer formation (1.05–1.4 V vs. SSCE). The dependence of the capacitance on potential was analysed. In both regions equivalent circuits composed of a resistor corresponding to the resistivity of the solution and a capacitor were proposed. It was found that in the double-layer region the capacitance reflected the properties of the pure gold electrode, whereas in the oxide region it depended on the coverage of the surface, corresponding partially to pure gold, MOH dipoles, oxide or a reconstructed gold surface. The improvements made by introducing a constant phase element instead of the capacitor and adding a parallel resistor in the oxide region were analysed. The roughness of the gold electrode was also estimated. The results obtained by impedance measurements were complemented by voltammetric studies to clarify the process, to confirm the measured values and to explain the meanings of the calculated parameters.
- Subjects :
- Constant phase element
General Chemical Engineering
Double-layer capacitance
Oxide
Analytical chemistry
Capacitance
Analytical Chemistry
Dielectric spectroscopy
chemistry.chemical_compound
chemistry
Electrical resistivity and conductivity
Saturated calomel electrode
Electrode
Electrochemistry
Subjects
Details
- ISSN :
- 15726657
- Volume :
- 388
- Database :
- OpenAIRE
- Journal :
- Journal of Electroanalytical Chemistry
- Accession number :
- edsair.doi...........6cf5cdbb86cc013897e04787b1513725