| 研究課題/領域番号 |
16K04891
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| 研究機関 | 滋賀県立大学 |
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研究代表者 |
クヤウアマン ジョンレーマン 滋賀県立大学, 工学部, 特任准教授 (70727867)
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| 研究分担者 |
松本 高利 東北大学, 多元物質科学研究所, 助教 (50343041)
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| 研究期間 (年度) |
2016-04-01 – 2019-03-31
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| キーワード | Polyol / Nanowires / Nanoparticles / Oleylamine / Cu-Co / Cu-Ni / Heptanol / Catalysts |
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| 研究実績の概要 |
The role of ethylene glycol(EG) has been studied theoretically using calculation chemistry and the results were verified experimentally an then method developed was extended to other polyols. Also, the selection of metallic sources was studied by using the pKa values. Thus, the criteria for the selection of metal salts and polyols has been established.
Cu-Ni NWs were synthesized using polyvinylpyrrolidine (PVP)-EG system. The formation of Cu NWs was elucidated as follows: at first, the Cu ions were partially reduced to form Cu2O. Then, the Cu2O nanoparticles (NPs) were re-dissolved and reduced to metallic Cu atoms that subsequently formed the Cu seeds. Thereafter, Cu seeds underwent etching to form multiply twinned particles (MTP) and then these grew to form metallic Cu NWs. Finally, Ni was reduced and deposited on the formed Cu NWs. Thus, Cu-Ni NWs with average diameter of~ 60 nm and length of 40 microns were synthesized. The catalytic activity of Cu-Ni NWs was evaluated using the discoloration of methylene blue in NaBH4 solutions. NWs showed high activity than NPs due to high electron transport and synergistic interaction between different metals.
On the other hand, the electrochemical behavior of Cu-Co nanostructures prepared in heptanol-oleylamine system was examined using the CO2 reduction reaction to HCOOH. The activity of Cu-Co nanotubes(NTs) was four times higher than Cu-Co NPs. This difference was ascribed to the shape and surface composition. These results show that Cu based NWs or NTs have high potential as bimetallic catalysts in several chemical reactions.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
3: やや遅れている
理由
The progress of the experiments and calculations were delayed due to difficulties in the synthesis and catalytic examination of Cu based nanostructures.
The main reason for the same are as follow:
a.The measurement of catalytic activity through gas conversion was proposed however the high cost of the devices to characterize and examine the catalytic activities of Cu based NWs was difficult. New alternatives were investigated taking in count that Cu based NWs can be oxidized in oxidizing media.
b.To determinate the most suitable alcohol to reduce simultaneously different metals with different reduction potential, a high number of polyols was examined by calculation chemistry and then experimentally verified. So we expended a lot time to finish the calculation part.
c. Although Cu-Co nanoparticles, Cu-Co nanotubes, Cu-Ni nanoparticles and Cu-Ni nanowires were synthesized, we are not able to obtain Cu-Co nanowires yet requiring further time to synthesize these.
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| 今後の研究の推進方策 |
a. The synthesis of Cu-Co nanowires using strong reducing polyols such as pentanediol and butanediol should be examined.
b. Enhancement of the catalytic activity of Cu-Co nanostructures should be carried out by controlling composition.
c. Measurement of electrical and magnetic properties.
d. The potential use in other fields should be studied.
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| 次年度使用額が生じた理由 |
Due to the high cost to buy devices for measuring the catalytic activities of Co-Cu nanostructures by using syngas method, we are not able to use the proposed money. In this regard, we look for other alternatives to examine the catalytic activities of our samples
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