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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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Photocatalytic activity of printed hybrid layers of titanium dioxide
Sýkorová, Kateřina ; Krystyník, Pavel (referee) ; Veselý, Michal (advisor)
The main aim of this thesis was to optimalise composition of the titanium dioxide with a silica binder deposited on a PET foil. Emphasis was put on achieving maximum possible adhesion and hardness of the layer and the effect on photocatalytic activity. For the evaluation of photocatalytic activity comparative experiments with prepared layers were performed. Benzoic acid, dimethyl sulfoxide and azo dye Acid Orange 7 were used as model pollutants. Photocatalytic activity was investigated using UV-VIS spectrophotometry, formal rate constants and degree of conversion were also determined. The study results can be used for removing water pollutants from the water solution.
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Photocatalytic activity of hybrid layers of titanium dioxide for water disinfection
Morávková, Eva ; Krystyník, Pavel (referee) ; Veselý, Michal (advisor)
This bachelor thesis deals with the preparation of thin layers based on nanoparticles of titanium dioxide and organosilica binder. The effect of the ratio of the two components on the properties of the formed immobilized layers is studied. Two different ratios between TiO2 and organosilica binder and two different types of commercially available oxides were used. The work focuses mainly on the formation of thin immobilized TiO2 layers and their properties. Their photocatalytic activity was determined by degradation of model pollutant in solution, as well as their mechanical hardness and layer adhesion were determined. All prepared layers were treated with muffle furnace annealing and UV-C curing. Samples that had undergone a complete treatment were subjected to individual tests. The model dye was Acid Orange 7. Photocatalytic activity was characterized by a formal 1st order rate constant, which was detected by UV/VIS spectrophotometry. Mechanical hardness and adhesion were determined using ISO standards.
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Material printing of UV dosimeters
Třešňáková, Andrea ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
The subject of this theses is a preparation of chemical UV dosimeters working on diverse principles and their printing. Three UV dosimeters were prepared. The first one is based on a photocalalytic reaction of titanium dioxide with redox dyes. Two other dosimeters are based on a reaction of a photolabile substance able to produce an intermediate reacting with a dye. Prepared dosimeter compositions were coated using a material roll-to-roll printing machine on a corona-treated PET foil. Prepared dosimeter compositions were calibrated for desired exposition to UV radiation doses. Validity of a reciprocity law was verified.
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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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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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