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Monitoring of photocatalytic activity
Jurášek, Martin ; Drbohlavová, Jana (referee) ; Veselý, Michal (advisor)
Bachelors thesis deals with kinetics of redox dye 2,6-dichloroindophenol degradation. Thanks to photo-reduced form is colourless, it’s suitable to use it for photocatalytic activity rapid assessment of the thin titanium dioxide layers. The thin layers of TiO2 were prepared using nano-crystalline titanium dioxide suspension with amorphous silica. These layers, including layers of redox dye, were deposited by material printing process. The rate of redox dye photo-reduction was monitored in dependence of number of thin titanium dioxide layers at different UV irradiance. Redox dye concentration was studied using UV-VIS spectroscopy.
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Titanium Dioxide for Photovotaics
Zbořilová, Zdeňka ; Ing. Dvonka Vladimír,Ph.D. (referee) ; Dzik, Petr (advisor)
This bachelor thesis deals with the utilization of titanium dioxide for photovoltaics. The theoretical part gives a brief outline on the properties, methods of preparation and utilization of titanium dioxide mesoporous thin films for solar cells (dye sensitized solar cells and hybrid ones). The practical part includes a preparation of dye sensitized solar cells and a basic study on their behaviour during light exposure.
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Porous layers of titanium dioxide
Sekerová, Kateřina ; Dvonka, Vladimír (referee) ; Dzik, Petr (advisor)
This thesis deals with the preparation, properties and methods of characterization of porous titanium oxide layers prepared by sol-gel process. The theoretical part contains a summary of the search methods of preparation and use of porous thin films of titanium dioxide photocatalysis. The practical part involves the preparation of sol suitable for printing of porous layers, the properties and characterization of these layers.
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Mesoporous and microstructured layers of titanium dioxide
Lepičová, Martina ; Ing. Viera Jančovičová,Ph.D. (referee) ; Veselý, Michal (advisor)
This bachelor thesis provides an overview of modern ways of titanium dioxide thin layer preparation including material printing and their principles. Preparation of tetrabutoxide sol as a precursor of titanium dioxide with diethanolamine and polyethylene glycol as templating agents and its delivery to glass substrate by material printing is described. This work is focused on characterization of prepared thin layers of titanium dioxide by optical microscopy and making of microphotography database of prepared samples.
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Possibilities of pesticide degradation by titanium dioxide
Píšťková, Veronika ; Veselý, Michal (referee) ; Vávrová, Milada (advisor)
The aim of this bachelor´s thesis is a selection of pesticides, which could be degradated using titanium dioxide. The first part of the paper deals with general pesticide characteristics, subdivision of pesticides, mode of action on target agents and transformations of pesticides within the environment – the metabolic and the non-metabolic tranformation. The second part of the paper deals with heterogeneous photocatalysis using semiconductor TiO2, which is activated by ultraviolet or solar radiation. Using this method pesticides could be transformed even into carbon dioxide, water and inorganic mineral salts. Furthermore, there are mentioned the factors, which affect degradation rate, analytical methods to determine kinetics of degradation and methods for monitoring transients and end products. By each group of pesticides there are stated the representatives from this group, which have been used for investigation of degradation methods. Furthermore are mentioned decomposition mechanisms of reaction and the intermediate products formed during the photocatalysis process.
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Preparation of photocatalytically active layers of titanium dioxide
Šeffer, Lukáš ; Jančovičová, Viera (referee) ; Veselý, Michal (advisor)
This bachelor work gives an overview about preparation of titanium dioxide and silicon dioxide thin films by sol-gel process, using coating methods as spin coating, dip coating, capillary and cell coating, flow coating, spray coating, pyrosol process, chemical vapour deposition and printing. The procedures of composite films preparation obtained by mixed sols of titanium dioxide and silica dioxide are also discussed together with preparation of double layer films, when titanium dioxide is coated on glass substrate covered by a silica dioxide layer. The methods of photocatalytic activity testing are the important part of this work.
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Preparation of Stuctured Thin Layers of Titanium Dioxide
Lukešová, Magdalena ; Jančovičová, Viera (referee) ; Veselý, Michal (advisor)
Cílem práce bylo seznámit se s dostupnými zdroji popisujícími zkoumanou tématiku tenkých vrstev oxidu titaničitého. Na připravených tenkých filmech byla studována fotokatalytická aktivita a indukované hydrofilní vlastnosti. Transparentní filmy oxidu titaničitého byly připraveny na sodnovápenatém skle metodou sol-gel. Na přípravu TiO2 solu byl použit tetraisopropoxid titaničitý (TTIP) jako prekurzor. Přidaný polyethylen glykol (PEG) sloužil jako strukturu-řídící složka, acetyl aceton zase ovlivňoval hydrolyzační a kondenzační reakce. Pro nanášení solu na skleněné destičky byla použita technika mikropiezo depozice. Na získaných filmech byla studována fotokatalytická aktivita prostřednictvím degradace 2,6-dichlorindofenolu (DCIP). Rychlost odbourávání DCIP byla vyjádřena pomocí formální rychlostní konstanty reakce prvního řádu. Měřením kontaktního úhlu byla zkoumána smáčecí schopnost vrstev. Filmy, které byly vystaveny ultrafialovému záření, se chovaly superhydrofilně.
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Deposition of the thin films for applications of advanced oxidation processes using metal dopants
KRAJČOVIČ, Jan
The aim of this diploma thesis is deposition of TiO2 thin films onto different types and sizes of substrates, and some of these layers dope by iron or silver. During the work was range of TiO2 layers created using a method of physical vapor deposition namely magnetron sputtering. For these processes was chosen the Dreva ARC 400 Hard Material Coating Plant device. The main aim of these depositions was to attempt to create TiO2 thin films on a substrates of larger surface than its in average laboratory processes usual. For this purpose were TiO2 layers deposited onto square glass plates of side length 10 cm. For comparsion and analysis were also as a substrates used microscope slides and fragments of silicon wafers. These substrates were used for testing of photocatalytic activity and on surface morphology (SEM). The theoretical part of this thesis aims to a methods of deposition TiO2 layers and their characteristics. In the experimental part is the used coating equipment and parameters of each deposition process described. Further the characteristics and results of individual experiments are described.
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