2009年3月
Electrical Double Layer Structure in Ionic Liquids: An Understanding of the Unusual Capacitance-Potential Curve at a Nonmetallic Electrode
JOURNAL OF PHYSICAL CHEMISTRY C
- ,
- ,
- ,
- 巻
- 113
- 号
- 9
- 開始ページ
- 3386
- 終了ページ
- 3389
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1021/jp8114447
- 出版者・発行元
- AMER CHEMICAL SOC
This study describes the causes of a U-Iike capacitance-potential (C-E) curve observed at nonmetallic electrode/ionic liquids (ILs) interfaces, in contrast to those observed at metal electrodes and expected according to the Kornyshev theory (Kornyshev, A. A. J. Phys. Chem. B 2007, 111, 5545). Several C-E curves were measured at glassy carbon (GC) and highly oriented pyrolytic graphite (HOPG) electrodes in three different ILs with inherent ionic concentrations of 6.4, 3.3, and 1.7 M. The minimum capacitance value (2.2 mu F cm(-2)) at the HOPG electrode is significantly lower than those at GC or metal electrodes (> 10 mu F cm(-2)). The degree of curvature of the "U-Iike" curve measured at the GC electrode decreases in the ILs with low inherent ionic concentrations. This observation is in agreement with the theoretical curves deduced by considering both semiconductor and Kornyshev theories and the inherent properties (concentrations, sizes of ions, dielectric constant, etc.) of ILs used. The capacitance at the GC electrode exhibits a complex potential dependence, being different from those at HOPG and metal electrodes that were explained using semiconductor and Kornyshev theories, respectively. Depending on the characteristics of ILs, both concepts of semiconductor theory and Kornyshev's model may be required to explain the C-E curves at the GC electrode.
- リンク情報
- ID情報
-
- DOI : 10.1021/jp8114447
- ISSN : 1932-7447
- CiNii Articles ID : 80020273636
- Web of Science ID : WOS:000263733200006