Back to Search
Start Over
Electrosorption capacitance of nanostructured carbon aerogel obtained by cyclic voltammetry
- Source :
-
Journal of Electroanalytical Chemistry . Jan2003, Vol. 540, p159. 9p. - Publication Year :
- 2003
-
Abstract
- Cyclic voltammetry experiments at various electrolyte solution concentrations (0.001–0.1 M) and scan rates (1 to 5 mV s−1) have been performed to study the electrical double layer (edl) formation in nanostructured carbon aerogel. The results show that carbon aerogel is a good edl capacitor and can be further divided into mesoporous and microporous capacitors. According to the experiments, the mesoporous capacitor shows a fast charging/discharging response and is only minimally affected by the electrolyte concentration and scan rate. Therefore, the specific capacitance of the mesoporous capacitor is found to be constant over a wide range of applied electrical potentials. On the other hand, the microporous capacitor shows a slow charging/discharging response and its capacitance strongly depends on the electrolyte concentration and potential. Unlike previous experiments, in which only a flat minimum was observed at the point of zero charge (pzc), in the current study, a deep minimum is observed near the pzc at low electrolyte concentration if a slow scan rate is used. This unique feature is a result of edl overlapping in the micropores and is consistent with the predictions by the Gouy–Chapman model employed in this study. Based on this behavior, a new approach is suggested for pzc measurements of solid porous materials for which a large portion of the surface area is in the micropore region. [Copyright &y& Elsevier]
- Subjects :
- *VOLTAMMETRY
*ELECTROLYTE solutions
Subjects
Details
- Language :
- English
- ISSN :
- 15726657
- Volume :
- 540
- Database :
- Academic Search Index
- Journal :
- Journal of Electroanalytical Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 9096857
- Full Text :
- https://doi.org/10.1016/S0022-0728(02)01308-6