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Synthesis, Characterization and Kinetic Study on Novel Catalysts Supporting Nanoporous Titanium Dioxide for Degradation Environmental Organic Pollutants

Rahimnejad, Sara | 2009

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  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 39878 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Gholami, Mohammad Reza; Taghavinia, Nima
  7. Abstract:
  8. Several nanostructured photocatalysts were prepared by sol-gel, hydrothermal and precipitation methods. The products were characterized by X-ray diffraction (XRD), nitrogen adsorption, UV-VIS diffuse reflectance spectroscopy, fourier transform infrared absorption spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM). Their Photocatalytic activities were evaluated by degradation of organic pollutants in liquid-solid system. In this research work, the influence of metal oxide, copper oxide, on structure of nanocrystalline mesoporous titanium dioxide were evaluated. Different molar percentages of copper oxide on the surface of titanium dioxide were loaded. The structure of nanoparticles with different methods, microscopic and spectroscopy were studied. The investigation showed that copper oxide can play an important role on the morphology of photocatalyst. The method of preparation of nanocrystalline titanium dioxide coated apatite bioceramic by using titanium isopropyl ortho titanate precursor in a sol-gel process is described. The photocatalytic activity of the resulting nanocrystalline titanium dioxide was evaluated by degradation of a sample of azo dye, methylene blue, in aqueous solution. The synthesized nanocrystal showed better activity than the commercial photocatalyst P25. The high activity was attributed to bioceramic absorption ability and physicochemistry included surface area and pore size. Subsequently, the preparation Ag/AgBr/TiO2 photocatalyst coated different bioceramic apatite (hydroxyl, flouro) has been noticed. The photocatalysts were prepared by precipitation method. For comparison Ag/AgBr/TiO2 and Ag/TiO2 by different titanium dioxide (808, P25) were also prepared. The photocatalytic activity was evaluated by degradation positive and negative gram bacteria (E.Coli, B.Sub). An ionic liquid template was also used to prepare nanocrystalline titanium dioxide. The role of ionic liquid as a template has been investigated. The synthesized photocatalyst by ionic liquid template show higher photocatalytic comparable titanium dioxide without ionic liquid for degradation azo dyes pollutants.The last part of thesis, related to my research activity on sabbatical leave in national university of Singapore. Synthesized nanoparticles which have between 10-60 nm particle sizes were prepared by hydrothermal method. Photocatalytic activity and different parameter such as calcination temperature, UV-Vis region were evaluated for selective CO2 photoreduction to methane. Subsequently, the role of linkage cyclodextrin derivatives such as carboxymethylβ-cyclodextrin to titanium dioxide was evaluated. The studied show the effect of cyclodextrin on increasing carbon dioxide photoreduction.

  9. Keywords:
  10. Titanium Dioxide ; Sol-Gel Method ; Hydrothermal Effect ; Ionic Liquids ; Environmental Pollutant

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