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Experimental verification of photocatalytic activity of TiO2 in concrete
Steinbergerová, Ivana ; Přikryl, Jan (referee) ; Hela, Rudolf (advisor)
This thesis is focused on gathering all available information on the application forms of photocatalytic TiO2 in concretes, especially in the surface layers of precast and monolithic structures. The paper describes in detail the properties of titanium dioxide alone, his special abilities, leading to a substantial improvement of the environment, through photocatalysis. Further verification methods are described photocatalytic activity of titanium dioxide and titanium dioxide application in real projects. The practical part is tested recipes of secondary coatings from the production of company Precheza a.s. Přerov.
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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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Study of xenobiotics and biologically active compounds degradation on titanium dioxide
Píšťková, Veronika ; Lisá,, Hana (referee) ; Vávrová, Milada (advisor)
Heterogenous photocatalysis using titanium dioxide seems to be a promising method for disposal xenobiotics from the environment. The aim of this diploma thesis is the study of degradation of selected xenobiotics and biologically active substrances applying this method. Theoretical part of diploma thesis deals with the principals of heterogenous photocatalysis by means of a semiconductor TiO2 and the examples of its possible application are mentioned too. The compounds which could be appropriate for a study of degradation were selected from the group of pharmaceuticals and pesticides. The properties of target substances and their environmental impact were described. Furthermore, a bibliographic search focused on the possibilities of their analytical determination was conducted. The experimental part of the thesis describes the experiments with photocatalyst in a form of powder as well as with immobilized photocatalyst in thin layer on a carrier. Identification and quantification of analytes was realized by high performance liquid chromatography with mass spectrometic detection.
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Separation of pollutants on photoreactors
Kurťák, Marek ; Šolcová, Olga (referee) ; Svěrák, Tomáš (advisor)
The diploma thesis deals with photocatalytic degradation of organic polutants on water- suspended UV activated anatase particles. The measurements are executed on a pilot plant UV photoreactor and the aim the thesis is to figure out the time course of azo dyes degradation under different photoreactor settings and subsequently infer the effectivity of the photoreactor under different settings. The degree of the aze dyes degradation is evaluated via UV-VIS spectrometry.
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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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Titania mesoporous films fabricated by material printing
Chludilová, Markéta ; Drbohlavová, Jana (referee) ; Dzik, Petr (advisor)
Thesis deals with the creation of thin layers of a porous titanium dioxide. The solutions for the formation of thin layers were prepared using a solgel method by mixing TTIP, polyethylene glycol of molecular weight 1500 and dimethyl, layers were subsequently printed by material printer to glass substrate and calcinated at 450 °C for 2,5 hours. Optical and SEM microscopy was used to observe structure of individual layers. Samples, that showed the greatest porosity, were subsequently studied by electrochemical measurments and by photocatalytic aktivity determined via hydroxylation of coumarin.
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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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Photocatalytic Activity of Titanium Dioxide Printed Layers
Novotná, Michaela ; Jančovičová, Viera (referee) ; Veselý, Michal (advisor)
This diploma thesis was focused on the preparation of self-cleaning and photocatalyticaly active titanium dioxide thin films. Transparent and porous thin layers of titanium dioxide were prepared from sol-gel containing titanium tetraisopropoxide (TTIP) as precursor with addition polyethylene glycol (PEG). Transparent thin layers of titanium dioxide were also prepared from colloidal solution titanium dioxide. The immobilization of thin titanium dioxide layers was performed by a sol-gel process on the soda lime glasses. Diffusion of sodium cation from soda lime glasses into titanium dioxide layer were blocked. Sol was deposited by printig method – micropiezo deposition. Sol and thin titanium dioxide layers were characterised by the physical-chemical method. For prepared sol viscosity, density and surface tension were measured. Thickness and hydrophilicity of titanium dioxide layers also were studied. The photocatalytic activity of the printed titanium layers were tested via the photocatalytic degradation of the 2,6-dichlorindophenol. The influence of addition PEG into the sol and influence of sol loading was studied. It was found that the addition of PEG into the sol significantly increased the photocatalytic activity of titanium dioxide layers.
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Titanium dioxide blocking layers fabricated by material printing
Lásko, Ondřej ; Pospíšil, Jan (referee) ; Dzik, Petr (advisor)
In this theses TiO2 blocking layers were fabricated using material inkjet printing and spincoating methods. These layers were then analyzed using cyclic voltammetry to find any defects and to determine the type of those defects. We found that layers of over 120 nm made using ITO glass and spincoating method had the best blocking capabilities. Blocking layers prepared using FTO glass were underperforming greatly throughout the whole experiment. We also achieved good results with material ink jet printing. The best results out of all printed samples were achieved with DPI of 635, although these layers also had problem with the electrolyte rising through microscopic pores in the layer thus changing the results.
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