Dynamics of Electrochemical Reaction at Metal Surface Studied by High Sensitivity Raman Spectroscopy
Project/Area Number |
02640264
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
固体物性
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Research Institution | Ishinomaki Senshu University |
Principal Investigator |
SASAKI Yoshiro Ishinomaki Senshu Univ., Dept. Basic Science, Assoc. Prof., 理工学部, 助教授 (90101154)
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Co-Investigator(Kenkyū-buntansha) |
HORIE Chuji Ishinomaki Senshu Univ., Dept. Basic Science, Prof., 理工学部, 教授 (10005168)
MAEDA Toshiteru Ishinomaki Senshu Univ., Dept. Basic Science, Res. Assoc., 理工学部, 助手 (80202307)
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Project Period (FY) |
1990 – 1991
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Project Status |
Completed (Fiscal Year 1991)
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Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥1,500,000 (Direct Cost: ¥1,500,000)
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Keywords | Electrode Reaction / Raman Scattering / Surface / Pt Electrode / Adsorbate / Ag Electrode |
Research Abstract |
Analysis of adsorbates on metal surfaces is very important for the study of chemical reactions at the surface or interface. The purpose of this project is to analyze the process of the electrochemical reaction on noble metal electrodes. We constructed a Raman spectroscopic system with very hi-h sensitivity consisting of a Raman Notch Filter, a single -rating spectro-raph and a diode-array equipped with an image intensifier. In-situ Raman spectra of the electrode were taken while the electrode potential was swept cyclicly. We studied an Ag electrode and a Pt electrode in H_2SO_4 solution, For the Ag electrode, SERS (Surface Enhanced Raman Scattering) spectra were observed in the potential range where the electrode surface was covered by the anodic film (Ag_2SO_4) for (1) Ag_2SO_4 film which grows through the anodic electrode reaction and (2) SO_4^<2-> ions chemisorbed on a silver cluster deposited on the anodic film. For the Pt electrode, we cannot expect the enhancement effect. The exp
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ected Raman intensity for monolayer adsorbates is much less than the background scattered by a window of the electrochemical cell and by the electrolyte. We accumulated a series of difference Raman-spectra as obtained by subtraction the spectrum taken at a potential in the double-layer region from the spectra obtained at various potentials. The accumulation time for each spectrum was 2 hr. The difference spectra in the oxide region turned out to be similar to the background itself caused by the potential dependence of the reflectivity of the electrode. We corrected the difference spectra for the change in the reflectivity. The potential dependence of the corrected spectra indicated that, in the oxide region, (1) the Raman intensity of SO_4^<2-> and HSO_4^- increase, and (2) a broad line shows up at about 500 cm^<-1>. (1) was attributed to an increase in the density of those adsorbates and/or those in the diffusion layer. The Raman band around 500 cm^<-1> was assigned to atomic oxygen adsorbed on Pt. The oxygen adsorbed on the Pt electrode has been identified by spectroscopic technique for the first time in this project. Less
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Report
(3 results)
Research Products
(5 results)