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Li Yanping 20130728 讨论制备方法对光催化剂 CuO/TiO 2 活性的影响
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Recent experimental summary Other researchers’ reports
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1.Fabrication and comparison of highly efficient Cu incorporated TiO 2 photocatalyst for hydrogen generation from water Efficient Cu incorporated TiO 2 photocatalysts for hydrogen generation were fabricated by four methods: in situ sol-gel, wet impregnation, chemical reduction of Cu salt, and in situ photo-deposition.
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Characteristics: different chemical states of Cu different distribution ratio of Cu between surface and bulk phases of the photocatalyst the Cu content in the photocatalyst play a significant role in hydrogen generation Conclusion: situ sol-gel method exhibited the highest stability
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It was discovered that the fabrication methods determined: the chemical state of Cu, distribution ratio of Cu within the photocatalyst, BET surface area of thecatalyst, crystal structure of the TiO2support.
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2. Wu and Lee reported that Cu doping within the TiO 2 lattice had a negative effect on photocatalytic hydrogen generation as opposed to Cu deposition. Wu NL, Lee MS. Enhanced TiO 2 photocatalysis by Cu in hydrogen production from aqueous methanol solution. Int J Hydrog Energy 2004;29:1601-5.
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3. Boccuzzi et al. compared properties and activity of Cu-TiO 2 prepared by wet impregnation and chemisorption hydrolysis methods, and found that samples with the same chemical composition exhibited a marked difference of up to 100 times in the hydrogenation of 1,3-cyclooctadiene. Boccuzzi F, Chiorino A, Gargano M, Ravasio N. Preparation,characterization, and activity of Cu/TiO 2 catalysts. 2. Effect of the catalyst morphology on the hydrogenation of 1,3- cyclooctadiene and the CO-NO reaction on Cu/TiO 2 catalysts. J Catal 1997;165:140-9. Boccuzzi F, Chiorino A, Martra G, Gargano M, Ravasio N,Carrozzini B. Preparation, characterization, and activity of Cu/TiO 2 catalysts. 1. Influence of the preparation method on the dispersion of copper in Cu/TiO 2. J Catal 1997;165:129-39.
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Recent experimental summary
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1.Different preparation methods of CuO/TiO 2 catalysts 1.1 The activity of catalyst
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1.2The stability of the catalysts The stability of the chemical adsorption 54.6%
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69.9% The stability of the ethanol impregnation
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-0.45 -0.3 Activity decline : x-initial initial 活性 1.34 倍,下降 1.5 倍
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H 2 -TPR
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1.3BET data of the catalysts Pore distribution of the catalyst 26nm 2nm,31nm
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3.9nm 3nm,33nm
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2% CuO/TiO 2 S BET (m 2 /g) Pore diameter (nm) Pore volume (cm 3 /g) Chemical adsorption 46.829.00.326 Composite deposition 47.233.30.372 Ethanol impregnation 46.931.80.370 Sol-gel 92.03.90.137 Simple wet impregnation 45.626.30.344 Second impregnation 44.925.90.322 Specific surface area,pore diameter and pore volume of the catalysts
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N 2 adsorption stripping curve
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H 2 -TPR
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Uv-vis
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Plasmonic photocatalysis(Ag/SiO 2 core –shell , TiO 2 ) Reason : TiO 2,3.2eV, near UV irradiation can excite pairs of electrons and holes Ag NPs, a very intense LSP absorption band in the near-UV a considerable enhancement of the electric near-field in the vicinity of the Ag NPs enhanced near-field could boost the excitation of electron –hole pairs But, Ag NPs, would be oxidized at direct contact with TiO 2 A Plasmonic Photocatalyst Consisting of Silver Nanoparticles Embedded in Titanium Dioxide
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To prevent this oxidation, Ag NPs have to be coated with a passive material, such as SiO 2, to separate them from TiO 2.
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