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Photocatalytic properties of hybrid titania-silica layers
Zbořilová, Zdeňka ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This diploma thesis is focused on the preparation of hybrid titania-silica layers. Titanium tetraisopropoxide and tetraethyl orthosilicate with Levasil were used as the precursors for TiO2 and SiO2 synthesis, respectively. The layers were deposited on substrates by material printing. Furthermore, this work is focused on study of the photocatalytic activity of prepared titania/silica hybrid layers. Photocatalytic activity of prepared layers was studied by measuring the oxidation of 2,6-dichlorindofenolu, oxidative degradation of stearic acid and oxidation of terephthalic acid. The influence of hybrid layers number on the photocatalytic activity was investigated.
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Photocatalytic activity of hydrothermal titanium dioxide
Lepičová, Martina ; Jančovičová, Viera (referee) ; Veselý, Michal (advisor)
Hydrothermal synthesis is one of the most widely used methods for preparing nanoparticles of titanium dioxide. The process carried out at elevated temperatures and pressure, which facilitates the transformation of amorphous to crystalline titanium dioxide. Change of reaction conditions of the process (reactants concentration, temperature, time, pH, etc.) leads to change in morphology, microstructure and crystallinity of titanium dioxide nanoparticles. In this work the method of titanium dioxide preparation is briefly described. The titanium dioxide was prepared from a precursor titanium oxochloride and potassium hydroxide as the precipitating agent. Thus prepared titanium dioxide was immobilized on a glass substrate by material printing. This is a modern, highly precise and contactless method for preparing thin films. The photocatalytic activity of printed thin films of titanium dioxide was investigated by degradation of 2,6-dichlorindophenol at different irradiance. It was found that the sample prepared by hydrothermal treatment at 160 °C shows very similar photocatalytic activity to Degussa P25.
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Sol-gel process using reverse micelles
Lukešová, Magdalena ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
Práce popisuje přípravu tenkých transparentních vrstev oxidu titaničitého metodou sol-gel procesu s reverzními micelami, které jsou jedinečným uskupením zajišťujícím uniformní velikost připravených částic. Neionogenní tenzid byl použit jako templát. Pomocí materiálového tisku, tedy specializovanou formou inkoustového tisku, byly připraveny tenké filmy oxidu titaničitého nanesením 1–4 vrstev. Po kalcinaci byly připravené vrstvy oxidu titaničitého charakterizované šířkou zakázaného pásu. Struktura vrstev byla popsána optickou mikroskopií a SEM. Fotokatalytická aktivita byla ověřena oxidační reakcí 2,6-dichlorindofenolu a rozkladem kyseliny stearové, která byla přímo natištěna na vrstvy oxidu titaničitého. Fotoindukovaná změna hydrofility byla studována pomocí měření kontaktního úhlu smáčení vody. Fotokatalytická účinnost připravených filmů rostla s počtem vrstev oxidu titaničitého.
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Photocatalytic activity of titania multilayer printed structures
Potočková, Lucie ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This thesis deals with the preparation of titanium dioxide films by the sol-gel process. Films were deposited by material printing on soda-lime glass plates. The thickness of layers was directed by repeated printing. Thus were prepared multi-layered TiO2 coatings. The surface topology of films was investigated by optical microscopy and scanning electron microscopy. The photocatalytic activity of these coatings was studied on a model compound 2,6-dichlorineindophenol. The influence of the number of TiO2 layers and the intensity of UV irradiation on the size of 2,6-dichlorineindophenol degradation rate constant was monitored. The photo-induced hydrophilic properties of prepared coatings were studied as well.
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Fabrication of titania mesoporous layers by material printing
Schovancová, Petra ; Drbohlavová, Jana (referee) ; Dzik, Petr (advisor)
This diploma thesis was focused on the preparation of mesoporous titanium dioxide layers. Mesoporous layers were prepared from titanium tetraisopropoxide as a precursor with addition diethanolamine and polyethylene glycol. These layers were deposited by material printing. This work was also focused on the characterisation of prepared layers. Hydrophilicity of titanium dioxide layers were studied. The photocatalytic activity of the printed titanium layers was tested by the photocatalytic degradation of stearic acid. Bang-gap studies were performed. Quality of prepared layers was inspected by optical microscopy, scanning electron microscopy and atomic force microscopy.
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Titania suspensions for material printing
Svoboda, Tomáš ; Drbohlavová, Jana (referee) ; Dzik, Petr (advisor)
This bachelor‘s thesis deals with the preparation of stable suspensions of titanium dioxide applicable for material printing. A wide range of dispersive environments stabilizing the nanoparticles of titanium dioxide was investigated. Commercially available aqueous dispersion and dry titania powder was used as the source of TiO2.The properties of prepared suspensions were evaluated and the most suitable suspension was used for material printing. This thesis focused on suspension‘s stability, sizes of particles dispersed in them, and in their rheological behavior. Furthermore, we analyzed the studied the properties of printed layers by SEM, optical microscopy, DLS and analytical centrifuge. We also evaluated the photocatalytic activity by monitoring the oxidation rate of coumarin to 7-hydroxycoumarin.
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Peroxotitanate gels suitable for piezoelectric print
Fuksa, Andrej ; Pekárková, Jana (referee) ; Veselý, Michal (advisor)
This thesis provide information about deposition of thin layers from peroxotitanate precursor. Precursor containing peroxotitanic acid and mixture of solvents (isopropanol and ethyleneglykol), was printed with the ink-jet material printer. Glass slides were used as a substrate. Prepared layers of gel did not show photocatalytic activity, therefore calcination at 450 °C, was used to a gel conversion. Structure of the layers was characterized using optical and SEM microscopy. Photoactivity of the layers was studied by a hydroxy-lation of cumarine.
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Optimization depozition variables during material printing of titania coatings
Mlčkovová, Hana ; Králová, Marcela (referee) ; Dzik, Petr (advisor)
This thesis studies the effect of conditions in the printing material layers of titanium dioxi-de sol-gel formulations for the print properties of the resulting films – TiO2, which were pre-pared from a precursor of titanium tetraisopropoxide (TTIP). Thin films were deposited on the printing material soda lime glass and the layer thickness was controlled by repeatedly apply-ing. Prepared films were subjected to observation under an optical microscope, and the thic-kness of the layers was measured by mechanical profilometry.
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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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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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