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Analysis of the effectiveness of the photocatalytic effect in surface treatments
Holubová, Petra ; Žák, Antonín (referee) ; Žižková, Nikol (advisor)
The thesis deals with the possible use of the photocatalytic effect in construction practice. Surfaces with this type of treatment have the ability of a so-called self-cleaning effect. Based on the research, the basic principles of the evaluation of photocatalytic substances and its possible applications were written down. Furthermore, the issue of staining facade plasters was outlined. The goal was to analyze the effectiveness of the photocatalytic effect in surface treatments. A photocatalyst of two types (anatase and rutile) and two rounds (2% and 5%) was added to the plaster mix. Next, the samples were contaminated with dyes and dust particles, and then the samples were placed in the QUV tester or exposed to outdoor climatic conditions. The photoactivity of individual plaster mixtures was evaluated on the samples based on color changes during testing. Plaster with TiO2 in the form of anatas dosed in 5%, according to a modified evaluation based on UNI 11259 and JIS 1703-2:2007 standards, photocatalytic properties, and thus a self cleaning process occurred.
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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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Synthesis and properties of ceramic nanoparticles based on anionic doped composite oxides of titanium
Kašpárek, Vít ; Veselý, Michal (referee) ; Cihlář, Jaroslav (advisor)
Master’s thesis deals with synthesis of anatase and its anion doping by carbo-nitridation. Prepared samples were used for testing of the photocatalytic activity. Low-temperature anatase was synthesized at 80 °C for 6 hours and carbo-nitridatation was carried out in ammonia/tetrachloromethane atmosphere at 500 °C for 3 hours. The influence of silver content on low-temperature crystallization of anatase was studied by reaction of titanium tetraisopropoxide with water. Silver nanoparticles were prepared by reduction of silver nitrate by D-glukose and sodium citrate. One of the results is the draft for one-pot synthesis of anatase by titanium tetraisopropoxide with complexing agent (sodium citrate, ammonium citrate, citric acid). The study of photocatalysis water splitting was carried out in the presence of 20 % vol. of methanol. Anatase prepared with citric acid has the highest photocatalytic activity (Pt 0,5 %) in UV/VIS spectral region. The activity achieved 38,6 % effectiveness of TiO2 standard (Degussa P25). Doping by nitrogen didn’t lead to increase of photocatalytic activity.
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Synthesis and photocatalytic applications of titanium dioxide
Solný, Tomáš ; Drbohlavová, Jana (referee) ; Vlček,, Jozef (referee) ; Ptáček, Petr (advisor)
V práci je zkoumán vliv podmínek na průběh hydrolýzy alkoxidů titanu a vlastností připravovaných nanočástic oxidu titaničitého s důrazem na teplotu a množství vody přítomné v systému. Připravované hydrolyzáty alkoxidů titanu a nanočástice oxidu titaničitého připravené z hydrolyzátů jsou studovány metodami XRD, DTA – TGA, SEM – EDS, BET a PCCS. Nanočástice magnetitu byly syntetizovány pomocí precipitační reakce z roztoku Mohrovy soli a jejich krystalová struktura, velikost a povrchové vlastnosti byly sledovány s vyhodnocením vlivu teploty a při modifikaci povrchu polykarboxyletherovým superplastifikátorem. Pro upevnění TiO2 na povrch magnetitu byla použita kombinovaná metoda aplikace vybraných nanočástic TiO2 s hydrolýzou TiO2 pomocí alkoxidů titanu za účelem přípravy fotokatalyticky aktivního core-shell práškového katalyzátoru s vylepšenými vlastnostmi adsorpce na povrchu. Studovány byly možnosti aplikace TiO2 na povrch Mn-Zn feritu, kdy byl studován vliv depozice tenkých vrstev C a Au na morfologii povrchu. Fotokatalytická aktivita vybraných připravených materiálů byla studována pomocí dekompozice methylenové modři v roztoku a par isopropanolu a ethanolu rozkládaných pomocí Mn-Zn feritu v experimentálním chemickém reaktoru s magnetickým polem stabilizovaným ložem nosiče katalyzátoru.
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Use of Advanced Oxidation Processes to remove selected pollutants from the water matrix
Minich, Marek ; Landová, Pavlína (referee) ; Repková, Martina (advisor)
This bachelor’s thesis deals with the topic of using Advanced Oxidation Processes (AOP) to remove selected pollutants from the water matrix via food dye Brilliant Blue E133 removal. For the AOPs reactions systems 3 types were chosen: UV/H2O2, UV/TiO2 and UV/H2O2/TiO2 system. Although the AOP reactor prototype has been constructed only for the TiO2 system, there has been proven efficiency for the two remaining systems. All three of these systems exhibited dye degradation level from 63,29 ± 9,97 % for UV/TiO2 system to 77,06 ± 2,23 % for UV/H2O2 system in 240 minutes long experiments. This thesis offers complex and up to date view regarding AOP issue in wider context and demonstrates its usefulness in half controlled conditions.
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Growth of single crystals and their basic characterization.
Hanzlíková, Kateřina ; Pospíšil, Jiří (advisor) ; Matěj, Zdeněk (referee)
Basic methods of single crystals growth have been studied in this bachelor thesis. The preparation of anatase and ruby single crystals has been realized by floating zone method in different compositions of the surrounding atmosphere. Crystallinity of prepared materials has been verified by Laue method. The same method has been used for orientation of the prepared single crystals along the principal crystallographic axes. The tetragonal structure of TiO2 has been proved by powder X-ray diffraction. The floating zone method has been found as a very suitable and effective method to grow anatase single crystals.
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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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Use of Advanced Oxidation Processes to remove selected pollutants from the water matrix
Minich, Marek ; Landová, Pavlína (referee) ; Repková, Martina (advisor)
This bachelor’s thesis deals with the topic of using Advanced Oxidation Processes (AOP) to remove selected pollutants from the water matrix via food dye Brilliant Blue E133 removal. For the AOPs reactions systems 3 types were chosen: UV/H2O2, UV/TiO2 and UV/H2O2/TiO2 system. Although the AOP reactor prototype has been constructed only for the TiO2 system, there has been proven efficiency for the two remaining systems. All three of these systems exhibited dye degradation level from 63,29 ± 9,97 % for UV/TiO2 system to 77,06 ± 2,23 % for UV/H2O2 system in 240 minutes long experiments. This thesis offers complex and up to date view regarding AOP issue in wider context and demonstrates its usefulness in half controlled conditions.
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