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Monitoring of photocatalytic activity using redox dyes
Uhrová, Ivana ; Drbohlavová, Jana (referee) ; Veselý, Michal (advisor)
The bachelor thesis deals with assessment of photocatalytic activity of titanium dioxide. The easiest and simultaneously the quickest way is bleaching of indicator ink based on redox dye. The theoretical part contains characteristics of several similar dyes and a description of ink-structure effect on total bleaching speed. The experimental part elaborately describes bleaching of indicator ink based on redox dye 2,6 dichloroindophenol, depending on the number of ink layers on photocatalytic active surface as well as on total amount of glycerol.
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Hybrid titania-silica layers on polymeric supports
Bednárková, Jana ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This bachelor thesis deals with titania-silica photocatalytic layers on polymeric supports. The theoretical part involves the study of properties and possibilities of preparing the layer and it is mainly focused on the influence of silica on the nature of layers. The experimental part of this thesis investigates the influence of layer thickness on the degradation rate of 4 different dyes.
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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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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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Titanium oxide and its properties in building materials
Rypák, Peter ; Vyšvařil, Martin (referee) ; Rovnaník, Pavel (advisor)
Theoretical part of thesis deals with conclusion of aquired informations about photocatalysis of titanium dioxide, its influence on properties of chosen building materials and its practic use in research of building materials with abitlity to decompose organic and anorganic matters. Experimental part deals with influence of quantity of titanium dioxide on mechanical strength of tested samples based on alkali activated slag and its ability to decompose organic colorant Rhodamine B
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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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Functional thin films for applications using advanced oxidation processes
ŠRAM, Vlastimil
This diploma thesis aims to optimalization the process of magnetron sputtering and creating of thin layers for use in advanced oxidation processes. During the work was created range of TiOx layers. For this process was used physical method of sputtering called PVD. The photocatalytic activity of the deposited films was tested by degradation of organic dyes Acid Orange 7. Furthermore, the layer was analyzed on surface morphology (SEM) and the layer thickness (profilometry). Study of created layers was focused on the link between the characteristics of each layer, deposition parameters and photocatalysis properties. Based on these results, the layers were applied in a system using AOP for the decomposition of organic substances. The first chapter is devoted to a summary of existing knowledge of photocatalysis and its principles. Another chapter is devoted to the theory and methods of applying thin layers and summary of knowledge of the low-pressure discharges. In the exprimental section there are described various components of the apparatus. Furthermore, the experimental part of the work focuses on the analysis of the optimization process of applying thin layers on titanium oxide. The last chapter of the thesis contains the results of the experiments on the basis of is designed another research progress of this issue.
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