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Your search keyword '"Miura, Takashi"' showing total 21 results
Start Over Author "Miura, Takashi" Journal journal of the electrochemical society
21 results on '"Miura, Takashi"'

18. Electrochemistry of Fe(II)/Fe in a Hydrophobic Amide-Type Ionic Liquid.

Author

Yan-li Zhu, Katayama, Yasushi, and Miura, Takashi

Subjects
ELECTRODES, ELECTROCHEMICAL analysis, ELECTROCHEMISTRY, IONIC liquids, DIFFUSION
Abstract

Electrode reaction of Fe(II)/Fe was investigated in a hydrophobic amide-type room-temperature ionic liquid, 1-butyl-lmethylpyrrolidinium bis(trifluoromethylsulfonyl)amide (BMPTFSA) containing Fe(TFSA)2 with and without an additive of acetonitrile (AN). A bright deposit obtained by gatvanostatic electrolysis at 150°C was confirmed to be crystalline Fe by X-ray diffraction. Addition of AN altered the coordination environment of Fe(II), the cathodic current density, and the diffusion coefficient, while the nucleation/growth process of Fe was classified into three-dimensional progressive nucleation under diffusion control regardless of the presence of AN. However, the morphology of deposit obtained in the presence of AN was better than that in the absence of AN. [ABSTRACT FROM AUTHOR]

Published
2012
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19. The Influence of Potential on Eof Silver and Formation of Silver Nanoparticles in Some Ionic Liquids.

Author

Fukui, Ryuta, Katayama, Yasushi, and Miura, Takashi

Subjects
NANOPARTICLES, IONIC liquids, CATHODES, NUCLEATION, CRYSTAL growth
Abstract

Electrodeposition of Ag was studied in several ionic liquids. When the potential applied more negative than -0.25 V vs. Ag l Ag(I), the cathodic current density reached in the diffusion-controlled region. The surface morphology of Ag deposits, the initial stage of nucleation and crystal growth behavior and the apparent current efficiency changed depending on the applied potential. These results indicate that the applied potential affects the electrodeposition processes of Ag under diffusion-controlled region. Since the electrode reaction rate is controlled by diffusion, the change of the surface morphology may be caused by the change of the double layer structure, which is expected to depend on the applied potential. In addition, Ag nanoparticles were obtained in the ionic liquid after potentiostatic cathodic reduction, suggesting a part of reduced Ag was dispersed in the ionic liquid. [ABSTRACT FROM AUTHOR]

Published
2011
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20. Electrodeposition of Gold in an Amide-Type Ionic Liquid

Author

Katayama, Yasushi, Endo, Tomoyuki, Miura, Takashi, and Toshima, Kazunobu

Abstract

Electrode reactions of monovalent and trivalent bromoaurates, [AuIBr2][?] and [AuIIIBr4][?], have been investigated in an amide-type ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide. [AuIIIBr4][?] could be reduced to metallic Au via an intermediate species, [AuIBr2][?], which was stable in the ionic liquid. [AuIBr2][?] could be prepared by a proportionation reaction of [AuIIIBr4][?] and Au in the ionic liquid. Although metallic Au was deposited on a glassy carbon substrate at -1.5 V vs. Ag/Ag(I), Au nano-particles with an average diameter of (2.6 +- 0.6) nm were formed and dispersed in the ionic liquid by potentiostatic cathodic reduction on a glassy carbon electrode at -2.5 V vs. Ag/Ag(I).

Published
2014

21. EQCM Measurement of Ag ( I )  ∕ Ag Reaction in an Amide-Type Room-Temperature Ionic Liquid

Author

Serizawa, Nobuyuki, Katayama, Yasushi, and Miura, Takashi

Abstract

Electrodeposition of silver was investigated using an impedance technique (separately excited, passive technique) electrochemical quartz crystal microbalance (EQCM) in a room-temperature ionic liquid. The mass changes during silver deposition and dissolution were observed with the current efficiencies of nearly 100% during potential sweep, constant potential step, and constant current step experiments. The product of the viscosity and density of the electrolyte near the electrode, ηLρL, can be estimated by the resonance resistance, which can be monitored simultaneously with the resonance frequency. The change in the ηLρLvalue during silver deposition was consistent with the change in the calculated concentration of Ag(I) near the electrode. During the outer-sphere electron-transfer reaction between ferrocenium and ferrocene, no significant changes in the mass and the ηLρLvalue were observed.

Published
2009
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