2004 Fiscal Year Final Research Report Summary
Electrochemical analysis at nanometer-scaled electrodes
| Project/Area Number |
14340232
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
分離・精製・検出法
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| Research Institution | University of Fukui |
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Principal Investigator |
AOKI Koichi University of Fukui, Graduate School of Engineering, professor, 工学系研究科, 教授 (80142264)
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| Co-Investigator(Kenkyū-buntansha) |
CHEN Jingyuan University of Fukui, Graduate School of Engineering, associate professor, 工学系研究科, 助教授 (50311676)
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| Project Period (FY) |
2002 – 2004
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| Keywords | ultramicroelectrodes / electrochemical analysis / halfwave potentials / transfer coefficient / ferrocene / voltammetry / surface energy / reaction rate constants |
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| Research Abstract |
The aim of this proposal was to investigate abnormal electrochemical behavior of redox reactions at ultramicroelectrodes when reaction domains are on nanometer scale. The abnormal behavior is exemplified by apparent variation of chemical equilibrium constants, reaction rate constants with electrode size. This behavior has been observed at namometer-scaled materials such as metal nanoparticles, nanometered thin films, and nano-clusters. The electrochemical analysis is favorable for this research in that the ultramicroelectrodes provides nano-meter circumstances as well as their detection on the nanometered scale.
The previous data of the relation between redox reaction rate constants and the electrode size were the shift of halfwave potentials of Fe(II)(CN)_6 and Fe(III)(CN)_6 with a decrease in the electrode radii. A criticism was presented in that the complexes might be adsorbed so that the redox behavior should be out of the ordinary behavior. In order to circumvent this criticism, we made efforts of searching other redox systems and fabricating nanometer electrodes. At present, we got extremely large transfer coefficients of ferrocene in dichloroethyne solution and TCNQ in acetonitrile. The large coefficient corresponds to enhancement of reaction rates, supporting quantitatively the higher activation with a decrease in material. In order to remove ambiguity of electrode geometry, theoretical work has been made for the analysis of experimental data. The some models have been presented for explaining the enhancement of the reaction rates. The authors think the enhancement is artially due to under estimation of the electrode radii.
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Research Products
(7 results)
