2015 Fiscal Year Annual Research Report
機能性グラフェンを用いた電子移動速度、活性、選択性の優れた光触媒の開発
| Project/Area Number |
15F15050
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| Research Institution | The University of Tokyo |
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Principal Investigator |
坂田 一郎 東京大学, 工学(系)研究科(研究院), 教授 (90555682)
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| Co-Investigator(Kenkyū-buntansha) |
WANG YANQING 東京大学, 工学(系)研究科(研究院), 外国人特別研究員
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| Project Period (FY) |
2015-04-24 – 2017-03-31
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| Keywords | graphene oxide / dispersion / stabilization / centrifugation / exfoliation |
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| Outline of Annual Research Achievements |
Various dimensions of graphene oxide (GO) sheets have been prepared and selected from the precursor exfoliated graphite with the aid of centrifugation method. By controlling the parameters (concentration, pH value, etc.) and the centrifugal speed, we can selectively obtain the GO fractions with sizes from 500 nm, 1 micrometer to around 5 micrometers. The obtained GO sheets with 5 micrometers were used for the functionalization. The use of poly(diallyldimethylammonium chloride), a typical cationic polyelectrolyte, to stabilize the obtained GO sheet in situ is vital for the massive production of graphene-based composites. The average thickness of the polyelectrolyte-stabilized GO sheets with around 1.3nm, 0.5nm thicker than the precursors, indicating the monolayer assembly via the electrostatic interaction. It was found that the stabilized GO nanosheets can disperse homogeneously into the 3D porous PVA materials and improve their properties in the application of supported catalysis and facilitate the ion penetrating ability.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
In order to prepare and construct the general research theme on functionlized-rGO-photocatalysts, targeting the enhanced interfacial charge transport and the engineering of active sites on GO, the single/few layer exfoliation via the modified chemical oxidization, size selection via centrifugation method and in situ stabilization via polyelectrolyte-induced electrostatic interaction have been carried out and the characterizations of corresponding products have been executed by using X-ray photoelectron spectroscopy together with other suitable analytical methods.
Nano sized Ag3PO4 particles have been decorated on the surface of the functionalized-rGO by a kinetic control method. The optimization of parameters for the size adjustment is under study now. In addition, the functionalized-rGO has a template role for the morphology control of poly(vinyl alcohol) materials together with enhanced interface interactions.
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| Strategy for Future Research Activity |
The sheet-shaped GO- poly(diallyldimethylammonium chloride) complexes retain and stabilized Ag ions on their surfaces through various ion sources (Na2HPO4/NaH2PO4/NaI) will be carried out and then the mixed translucent solution will be transferred into a low temperature or UV-assisted reduction process. Some analysis such as the X-ray photoelectron spectroscopy and other suitable techniques will be used to explain the role of poly(diallyldimethylammonium chloride) as the linker and stabilizer between rGO and Ag(3)X (X= PO4, I) nanoparticles.
Observations on the morphology control and structural evaluation of as-prepared materials will be performed by using high resolution TEM, X-ray diffraction, and other analytical methods. In addition, the catalytic performances of the products with the comparison of commercial materials such as tungsten oxide, titanium dioxide will be carried out under visible light irradiation. Furthermore, the as-prepared stabilized rGO aqueous solution will be used as the electrode material for the analysis of ion adsorption/desorption ability in electrochemical method.
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