Electrochemistry
Online ISSN : 2186-2451
Print ISSN : 1344-3542
ISSN-L : 1344-3542
Volume 68 , Issue 12
Showing 1-29 articles out of 29 articles from the selected issue
Vision
Headline
  • Bruno PETTINGER, Gennaro PICARDI, Rolf SCHUSTER, Gerhard ERTL
    2000 Volume 68 Issue 12 Pages 942-949
    Published: December 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    The surface enhancement of the Raman scattering (SERS) is based on two major mechanisms. First, the optical resonance of the incident light with the metallic surface leads to the excitation of localized surface plasmons and the enhancement of the local electromagnetic field. Second, optical resonances of the energy levels between the adsorbate orbitals and the metal electrons may result in a resonant charge transfer, which causes the resonance Raman or charge transfer enhancement. For dyes at aggregated colloids, the total differential cross sections can reach values of about (dσ/dΩ) ~10−16 cm2 sr−1, which are comparable with cross sections for the fluorescence of laser dyes in solution. In contrast, Raman spectroscopy at surfaces that do not support surface plasmon excitation (smooth surfaces or transition metal surfaces) is based solely on chemical or resonance Raman enhancement, yielding only weak signals. After reviewing recent results on SERS, we present an approach that combines the Raman spectroscopy at smooth surfaces with the local electromagnetic field enhancement by an optically active Ag STM tip. The high local enhancement of the Raman scattering cross section in the vicinity of the tip opens promising avenues towards single molecule Raman spectroscopy.

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Communication
  • Koji FUSHIMI, Tsuyoshi OKAWA, Masahiro SEO
    2000 Volume 68 Issue 12 Pages 950-954
    Published: December 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    A scanning electrochemical microscopic (SECM) observation of oxygen evolution on a polycrystalline titanium electrode during anodic oxidation in 0.1 mol dm−3 H2SO4 was attempted to evaluate the heterogeneity of the electrode surface. The micro probe electrode, which was scanned above the titanium electrode surface, could detect oxygen evolved in parallel with the formation of anodic oxide film. The probe current image corresponding to the distribution of oxygen evolution was in good agreement with the conventional probe current image measured in pH 8.4 borate solution containing K4Fe(CN)6, indicating that the oxygen evolution took place preferentially on the substrate grain covered with the thinner oxide film. It is shown that the SECM measurement of oxygen detection is useful for in-situ evaluation of the heterogeneity of anodic oxide film on the metal electrode during anodic oxidation.

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Technical Papers
  • Akira KUNUGI, Md. Abdul JABBAR, Shuichi NAITOH, Mikito YASUZAWA, Hidem ...
    2000 Volume 68 Issue 12 Pages 955-962
    Published: December 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    The introduction of sulfur atoms into trifluoromethylated alkenyl sulfones and chlorides were studied using a reactive sulfur-graphite electrode in N,N-dimethylformamide. A substrate, 2-(4-biphenylyl)-4,4,4-trifluoro-3-phenylsulfonyl-2-butenenitrile (1a) afforded a coupling compound bridged with a nitrogen atom of isothiazole and 1,2-dithiolane skeleton (2). 1-(4-Biphenylyl)-3,3,3-trifluoro-2-phenylsulfonylpropene (1b) without a cyano group gave a complex oligomeric compound (3) without the elimination of the phenylsulfonyl group. 2-(4-Biphenylyl)-3-chloro-4,4,4-trifluoro-2-butenenitrile (1c) having a chloro group as a leaving group gave 2,4-di (4-biphenylyl)-2,4-dicyano-l ,5-bis(trifluoromethyl)-3, 6-dithiabicyclo [3.1.0] hexane (4) and 2-(4-biphenylyl)-4,4,4-trifluoro-2-butenenitrile (5). Methyl 2-(4-biphenylyl)-3-chloro-4,4,4-trifluoro-2-butenoate (1d) having an ester group in the place of a cyano group afforded di- [2-(4 biphenylyl)-2-methoxycarbonyl-1-trifluoromethylethyl] disulfide (6). The formation of such sulfur-containing organofluorine compounds except for the oligomeric compound 3 is characterized as the addition of polysulfide anion(s) produced by electroreduction of elemental sulfur, followed by the elimination of the phenylsulfonyl or the chloro group.

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  • Masaaki ISAI, Hiroshi ICHIKAWA, Hironobu TAKAHASHI, Hiroshi FUJIYASU, ...
    2000 Volume 68 Issue 12 Pages 963-966
    Published: December 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    Manganese oxide films for lithium secondary batteries were prepared using a reactive evaporation method. One of the problems is that the manganese metal in the crucible (Mn evaporant) suffers oxidation from oxygen atmosphere. This deteriorates the Mn deposition rate with increasing the deposition run. The feasibility of overcoming the oxidation of Mn metal in the crucible was investigated in the present paper. A separator was introduced in the bottom of the Mn crucible. It can isolate Mn evaporant from incoming oxygen atoms. It was found that the oxidation of Mn evaporant could be inhibited up to the oxygen flow rate of 7 sccm. It can also improve the reproducibility of deposition process because of stabilizing the deposition rate.

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  • Ichiro SHIMOURA, Masayuki TERADA, Yutaka YAMAGUCHI, Masayuki TAKASHIMA
    2000 Volume 68 Issue 12 Pages 967-971
    Published: December 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    One of the most important problems to develop the long-lived valve regulated lead acid battery is the intergranular corrosion of the cathode grid made of Pb-Ca-Sn alloy during trickle charging. To prevent the corrosion, the electroconductive perovskite type oxide films containing lead metal were formed on the surface of the cathode grid. As the results of surveying various systems between β-type lead oxide (β-PbO2) and metal oxides or hydroxides, it was confirmed tha BaPbO3 and SrPbO3 were formed even at 300°C (mp of Pb-Ca-Sn alloy, 320°C). The life of trickle-charging test of the battery with the cathode, of which grid was covered with SrPbO3, was twice longer than that of the standard battery without the perovskite oxide treatmeat.

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  • Yoshinari KITTAKA, Masashi ITO, Sachio YOSHIHARA, Takashi SHIRAKASHI, ...
    2000 Volume 68 Issue 12 Pages 972-976
    Published: December 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    The electrochemical reactions on conducting boron-doped diamond films were investigated, The study was focused on electrodeposition of copper on heavily boron-doped diamond electrode surfaces with hydrogen and oxygenterminations, The peeled-off copper layer deposited on the hydrogen-terminated diamond surface was a good replica of the diamond surface morphology, By the contrast, the peeled-off copper layer deposited on the oxygen-terminated diamond surface did not replicate the diamond surface morphology,

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  • Shigeo TAKEUCHI, Shin'ichi MAGAINO, Koichi KOBAYAKAWA, Yuichi SATO
    2000 Volume 68 Issue 12 Pages 977-983
    Published: December 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    The cause of the memory effect observed in alkaline-type rechargeable batteries was studied. It is found that γ-NiOOH initially forms at the collector side and it grows to the solution side as shallow charge-discharge cycling progresses. The charge transfer resistance of the charged-state Ni-electrode increases with shallow charge-discharge cycling. These results suggest that the memory effect is mainly caused by the formation of γ-NiOOH.

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  • Akio TANAKA, Hiroki TAMURA, Shinichi KIKKAWA
    2000 Volume 68 Issue 12 Pages 984-988
    Published: December 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    Lambda-MnO2 has the ability to incorporate Li+ ions in solution selectively into its lattice vacancies, and can be applied as a sensor material for Li+ ions and as an agent for recovering Li+ ions from seawater. The surface of λ-MnO2 in water is hydroxylated, and ion exchange reactions at surface hydroxyl groups may bring other ions into the recovered Li+ ions. The amount of Na+ ions adsorbed by exchanges with surface hydroxyl protons was measured by titration in NaNO3 solutions, and modeled by considering reaction stoichiometry and equilibrium conditions with the Frumkin equation. The model equations reproduce the measured data, and can be used to estimate the amount of Na+ ions contaminating the recovered Li+ ions. A method for reducing the contamination due to adsorbed Na+ is proposed.

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  • Kei MAKITA, Takeshi OKUYAMA, Fumio ANDO, Jugo KOKETSU
    2000 Volume 68 Issue 12 Pages 989-991
    Published: December 05, 2000
    Released: November 10, 2019
    JOURNALS OPEN ACCESS

    In order to use for separation and qualitative analysis of phosphonium ions, the paper electrophoresis was applied on the fourteen triphenylphosphonium ions which have the linear chain alkyl substituents from methyl to octyl groups on the phosphorus atom along with benzyl, acetylmethyl, benzoylmethyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, cyanomethyl substituents. Good correlations have been found between the average mobilities and the molecular weights.

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Special Articles
Biomimetic Electron Transfer Reactions (2)
21st Century Special Issue (1)
The Way to 21st Century
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