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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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Electroassisted photocatalysis
Filipská, Markéta ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This thesis is focused on fotoelectrochemical cells, where as photocathode is used titanium dioxide coated on conductive FTO glass and as counter electrode is used gold electrode. Thesis is also focused on relationship between intensity of irradiation and Faradaic efficiency and also influence of the overvoltage to the rate of degradation od the model pollutant, in this case Acid Orange 7. Electrical properties were measured by recording values of photocurrent. The aim of this thesis was to study influence material composition of photoanode and connection with intensity of irradiation, rate of degradation proces of model pollutant and current.
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Photocatalytic activity of hybrid titanium dioxide layers treated by plasma
Koukolová, Anna ; Králová, Marcela (referee) ; Veselý, Michal (advisor)
The bachelor thesis deals with photocatalytic activity of thin layer of titanium dioxide deposited onto PET flexible foil treated by plasma. Photocatalytic activity is measured by two different methods, degradation of dye Acid Orange 7 and benzoic acid. Possible model compounds for evaluation of photocatalytic activity as well as deposition techniques for preparing thin layers of photocatalyst were discuss in the theoretical part. Changes of photocatalytic activity were found insignificant with plasma treatment. Evaluation used Acid Orange 7 is suitable. Unlike method with benzoic acid was discovered inappropriate for measuring of photocatalytic activity for photocatalyst deposited onto PET foil.
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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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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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