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Fabrication and characterization of oxidic conductive layers
Bartoš, Radim ; Gemeiner,, Pavol (referee) ; Dzik, Petr (advisor)
Liquid composition for antimony doped tin oxide solgel deposition was prepared. Anorganic precursors of tin and antimony were used (tin(IV) chloride, antimony(III) chloride). ATO nanoparticles were dispergated in composition. This composition was used for spincoating deposition of thin films. Composition was analyzed by thermal analysis TGA and DSC. Sheet resistence of prepared samples were examined by four probe sensing. RMS roughness and thickness was measured by profilometry. Samples were analyzed by scan electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Transmittance and haze were measured and calculated by UV-VIS spektrometry with integration sphere.
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Synthesis and Characterization of PVAl Acrylic Esters
Hynštová, Karolína ; Jančovičová, Viera (referee) ; Dzik, Petr (advisor)
The diploma thesis deals with a detailed study of he esterification reaction between PVAl and acrylic and methacrylic acids. Tha goal is to prepared PVAl-based macromers bearing (meth)acrylic moieties bound to PVAl macromolecular backbone. Attention will be paid especially to equlibrium establishing times and to the influence of reaction mixture composition on the properties of resulting products.
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The influence of material composition and spatial arrangement on the properties of photoelectrochemical cells
Pachovská, Martina ; Krystyník, Pavel (referee) ; Dzik, Petr (advisor)
This diploma thesis deals with photoelectrochemical cells containing photoactive titanium dioxide anode and their use for photocatalytic degradation of organic compound from water solutions. The electrical properties of the produced photoelectrochemical cells were determined by the use of voltamperometric characteristics, the oxidation ability of the cells was monitored by measuring the fluorescence of the oxidative intermediates. To study these reactions, benzoic acid was used as the fluorescence probe for OH˙ radicals. The aim of the study was to study the influence of material composition and spatial arrangement of the cathode and the relationship between irradiation, current and rate of electrode processes.
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Plasmochemical treatment of photoanodes with semiconducting oxide layer
Ďurašová, Zuzana ; Zita, Jiří (referee) ; Dzik, Petr (advisor)
This diploma thesis deals with a plasmochemical treatment of photoanodes with an active layer containing TiO2 deposited on two different substrates by material printing. The plasmochemical treatment was performed by a low-temperature ambient-air plasma using a diffuse coplanar surface barrier discharge (DCSBD). The experimental part is focused on the investigation of DCSBD influence on the fabricated photoanodes photoelectrochemical properties, and the influence of plasma treatment time. Process optimization was achieved by height adjustment of the electrode. The processed coatings were electrochemically investigated by linear sweep voltammetry and chronoamperometry.
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Automated determination of photocatalytic self-cleaning surface activity by color indicator inks
Bednárková, Jana ; Morozová, Magdalena (referee) ; Dzik, Petr (advisor)
Tato diplomová práce se zabývá testováním vhodných indikátorových inkoustů k ohodnocení fotokatalytické aktivity. V teoretické části jsem studovala literaturu související s možnostmi stanovování fotokatalytické aktivity a zaměřila se také na kinetiku, kterou je zmíněnou fotokatalýzu možné ohodnotit. V experimentální části jsem mnou vybraná barviva natiskla na skleněný substrát obsahující vrstvu oxidu titaničitého a následně je otestovala. Došlo také k úpravě aparatury, aby bylo možné měřit větší škálu barev. Po otestování a vybrání vhodných barviv jsem se pokusila o optimalizaci podmínek tisku. Nakonec jsem optimalizovala i samotnou aparaturu.
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Fabrication and characterization of tungsten trioxide photoanodes
Hesková, Helena ; Králová,, Marcela (referee) ; Dzik, Petr (advisor)
This work deals with the optimization of the preparation process of WO3 photoanodes nad their characterization. For compositions were prepared, which were applied to a substrate via spin-coating process and subsequently annealed at 450 °C. The length of milling of precursor particles contained in the coating formulations determined properties of deposited layers. were examined for. The additivity of the individual compositions was also observed. The structure of the layers was observed by optical microscopy and scanning electron microscopy (SEM), their composition by the X-ray diffraction (XRD) and their thickness and surface roughness was defined by contact profilometry. Photoelectrochemical properties of the prepared layers were also investigated by linear voltametry and chronoamperometry.
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Influence of surface electrodes on the ozone generation in the dielectric barrier discharge.
Mierna, Jana ; Dzik, Petr (referee) ; Mazánková, Věra (advisor)
The bachelor´s thesis is focused on the study of influence of adsorbed gases on the electrode surface on ozone generation in dielectric barrier discharge. The theoretical part describes some basic properties and applications of ozone, methods of its generation, determination and interaction with the solid surfaces. In the experimental part was studied formation of ozone by the recombination of molecules and atoms of oxygen on the wall of electrodes and also its destruction caused by the reaction with particles present in closed ozoniser without discharge. Ozone was generated in cylindrical configuration system of electrodes made of staniless steel and alumina ceramics as dielectric material. Several series of experiments were measured by using various operating gases (oxygen; oxygen and argon; oxygen and nitrogen). It was also examined the decrease of generated ozone concentration in long-term operation by using pure oxygen of 99,999 90 % as a feeding gas. The resulting ozone concentration for given reaction time of individual measurements was determined by the method of absorption spectrometry.
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The influence of titania morphology on the physico-chemical properties of photocatalytic coatings
Saňák, Tomáš ; Cihlář, Jaroslav (referee) ; Dzik, Petr (advisor)
This bachelor thesis examines two variously milled liquid dispersions containing titanium dioxide and coatings made by them. First dispersion was provided by partners from COC s.r.o. Pardubice and was prepared by high-energy milling. Second disperzion was milled in improvised ball-mill. Coatings prepared from these disperzions were applied on two various substrates (microscopic glass, FTO glass) and were characterized by three analytical methods (profilometry, haze measuring, electrochemical measuring). Profilometry and haze measuring reported about decreasing properties of layers according to milling time. Electrochemical measuring used to explore photocatalytic properties showed us that photocatalytic activity requiere optimal milling time.
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Organic dye decomposition by AOP´s methods
Olexová, Barbora ; Dzik, Petr (referee) ; Kozáková, Zdenka (advisor)
This diploma thesis is focused on the study of the influence of advanced oxidation processes on degradation of organic dyes. The field of AOP – very effective physically-chemical methods of wastewater treatment – includes application of strong oxidation agents, UV and ionizing radiation and electrical discharges. For this thesis, two of these methods were chosen – the application of oxidation agent (ozone) and UV radiation. Along with electrolysis, which is mentioned rather marginally in this thesis (it is the subject of the previous thesis), these phenomena are products of electrical discharge in water, where they participate in the processes of degradation in a different way. For all measurement series, two direct azo dyes were chosen as model substances – C.I. Direct Blue 106 and C.I. Direct Red 79. The ozonizer, in which either oxygen or synthetic or technical air were loaded as carrier gases, was used for degradation of dyes by ozone. The generated ozone was loaded into the bubbling vessel with dye solution of different initial concentration (10–130 mg.dm-3), which was followed by other bubbling vessel with KI solution for the next analytical determination of the amount of generated ozone. The other parameters changed were the gas flow (1–2 dm3.min-1), ozonizer output (minimal and maximal), type of dye, pH value of the solution (neutral or acid) and additional electrolyte (NaCl, Na2SO4 or any). The reactor for the study of the influence of UV radiation on degradation of dyes was an UV sterilizer into which the equivalent volume of dye solution was added. The possibilities of experimental settings were limited and only the type of dye, an additional electrolyte and pH value of the dye solution were adjusted (as in the case of ozone). Several series of samples were measured with various input conditions which more or less influenced the degradation of investigated dyes in this experiment. It was found that for both used methods the Direct Blue 106 dye was more degradable (with significantly better results for ozone than for UV radiation). The degradation of Direct Red 79 dye proceeded only by ozone treatment, in the case of the application of UV radiation no degradation occurred. By investigation of the influence of initial concentration of dye on its degradation, it was confirmed that with the initial concentration enhancement the final concentration rises as well, whereas in low concentrations (10–50 mg.dm-3) the initial concentration has no effect. The addition of an electrolyte had an accelerating effect on dye degradation in both methods (NaCl and also Na2SO4 showed similar results though the degradation proceeded in different ways). The addition of HCl accelerated the degradation only in the case of UV radiation; during the application of ozone the pH level of the system did not have any influence on the degradation. Oxygen and synthetic air had the strongest effect on ozone degradation (comparable results); in the case of technical air the final dye concentration was higher up to 30 %. The gas flow of 1.5 dm3.min-1 was stated as optimal with the ozonizer output 30 W (maximal). At minimal power the ozonizer produced very low amount of ozone.
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Printed photoelectrochemical sensor for blue light
Papák, Jiří ; Hatala,, Michal (referee) ; Dzik, Petr (advisor)
This diploma thesis focuses on electrochemical sensors to detect radiation in the blue region of the visible spectrum. As a semiconducting material for the manufacture of the sensor, a suspension of tungsten trioxide was found. The individual elements of the sensor were applied by pad printing techniques or screen printing. Using linear voltammetry and chronoamperometry, the magnitude of the generated current was measured and radiometric calibration was performed. The properties of the layers were characterized by profilometry, optical and electron microscopy.
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