| Since the demonstration by Honda and Fujishima of the photoelectrolysis of water using a TiO2 electrode under an anodic bias potential, intensive research efforts have been devoted to the development of photocatalytic materials, with the aim of utilizing solar energy and thus addressing the increasing global concerns of environmental remediation and clean fuel production. Decades of efforts have successfully produced a wide range of efficient semiconductor—based photocatalytic materials for solar energy conversion and environmental remedy. Photocatalysts with high performance have been successfully fabricated by the investigators all over the world. Among various oxide semiconductor photocatalysts, TiO2 was generally recognized as the most promising one due to its biological and chemical inertness, superior photo oxidative, low cost and long—term stability. It has been widely used in photocatalytic applications, including the degradation of organic pollutants in aqueous and gaseous phases, removal of heavy metals from contaminated waters, hydrogen gas generation from photocatalytic water splitting, etc. Especially, TiO2 based photocatalysts with advanced mircrostructures would possess higher performances and potential in these applications.Recently, people investigated the TiO2 materials at molecular level through a lot of research and found that the meta—stable{001} facets of anatase are more reactive than the other ones. The investigations related to{001} facets of anatase TiO2 has now become a hot topic in the field.On the other hand, PAHs has been known as typical POPs, which are carcinogenic, teratogenic, mutagenic or endocrine disrupting to organisms. The photochemical behaviors of PAHs over atmospheric particles is an typical transforming pathway, so that studies on PAHs photocatalytic degradation over the surface of catalyst particles would make an important contribution to theretical and practical aspects.In this thesis, we carried out the following three aspects of investigations about the anatase TiO2 with{001} facets:(1) Flower—like anatase TiO2 assemblies with dominant{001} facets exposed were synthesized by a simple, economical hydrothermal route with titanium sulfate and hydrofluoric acid. Their surface morphology and structure were investigated by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, X—ray diffraction, and Brunauer—Emmet—Teller N2 gas adsorption—desorption isotherms. The optical property and the photo—induced charge carriers of the flower—like TiO2 were studied by UV—vis diffuse reflectance spectroscopy and transient photovoltage technique. The flower—like TiO2 particles exhibited a good photocatalytic activity in degrading rhodamine B.(2) Due to the strong adsorptive capability of the biological material—hydroxyapatite, we loaded it with the flower—like TiO2 together, so that we could combine the adsorption of the hydroxyapatite and the photocatalytic of the flower—like TiO2. Through some modern characterization techniques such as SEM, XRD, DRS, EDS, FTIR, XPS and so on, we proved that hydroxyapatite was successfully loaded on the flower—like TiO2. At the same time, we used them to degrading rhodamine B to compare their photocatalytic activity.(3) The in-situ transmission infrared spectroscopy was used to study the photocatalytic reaction of the naphthalene on flower—like TiO2 and HAP/TiO2, and the experimental was carried out under UV irradiation. And the results showed that under the UV irradiation, the nanphthalene's ring will be opened, and the reaction intermediate products were aromatic ketons, Propyl hydroxybenzoate, carboxylic acid, benzene formaldehyde, and the final products are carbon dioxide and water. |
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