Another study was to prepare hierarchically mesoporous titania materials with well-defined grape-like morphology in the presence of a triblock copolymer using bubbling-mediated hydrolysis approach. The effects of bubbling time and calcination temperature on both physicochemical and photocatalytic properties were investigated. / Furthermore, thermally stable ordered mesoporous CeO2/TiO 2 visible photocatalysts were prepared by the evaporation-induced self-assembly method. Introducing highly dispersed CeO2 species into the mesoporous TiO2 framework could effectively extend the response of TiO 2 to visible light region and improve the thermal stability of the mesoporous TiO2. / In addition, visible-light-driven mesoporous TiO2-xN x photocatalysts were developed via in-situ pyrolysis of the product from a chelation reaction between TiCl4 and ethylenediamine under sonication. The effects of ultrasound bombardment on the physicochemical properties and photoactivity of mesoporous TiO2-xNx were discussed. / Part I. Ordered and well crystallized cubic Im 3¯ m mesoporous Cr-TiO2 photocatalysts were fabricated through EISA (evaporation induced self assembly) process. The as prepared photoactalysts exhibited very strong photoactivity in the degradation of methylene blue under visible light irradiation owing to the excitation of 3d electron of Cr3+ to the conduction band of TiO2. / Part II. New approaches have been developed for the fabrication of visible light photocatalysts, BiVO4 and Bi 2WO6. In the case of BiVO4, ordered mesoporous bismuth vanadate (BiVO4) crystals were synthesized via nanocasting method. Compared to the conventional BiVO4, the product exhibited superior photocatalytic performance in the photochemical degradation of methylene blue and photocatalytic oxidation of NO gas in air under visible-light irradiation. In addition, hierarchical flower-like Bi2WO6 was synthesized via microwave-assisted route. Compared to the samples prepared by the hydrothermal method, the products exhibited excellent photocatalytic activities of degrading methylene blue and photocatalytic oxidation of NO gas in air under visible light irradiation. The effects of microwave irradiation on both physicochemical and photocatalytic properties of the as prepared products were investigated. / Two different types of porous visible light photocatalysts were studied in this thesis. The first part reports on the improvement of photocatalytic performance of porous TiO2 through metal/nonmetal doping and morphology controlling. The second part describes the fabrication of porous non-TiO2 photocatalysts including BiVO4 and Bi2WO6. / . / Adviser: Jimmy C. Yu. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3527. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_344273 |
| Date | January 2008 |
| Contributors | Li, Guisheng., Chinese University of Hong Kong Graduate School. Division of Chemistry. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, theses |
| Format | electronic resource, microform, microfiche, 1 online resource (xxiii, 219 leaves : ill.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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