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82. Zr/Cu-TiO2 CATALYSTS FOR PHOTOCATALYTIC WATER TREATMENTOlena Pliekhova, 2019, doktorska disertacija Opis: This work entitled «Zr/Cu-TiO2 catalysts for photocatalytic water treatment» tackles a problem of tons of dyes discharged everyday mainly from textile industries. This is a huge concern because of dyes persistence, toxicity and potential to the bioaccumulation in living organisms. Here, a small contribution to overall problem is presented.
The research work consists of three main parts: Theoretical background, Experimental and Results and discussion. In the Theoretical background chapter the overall problem is identified and discussed. The main water treatment techniques are presented briefly with their advantages and drawbacks. Photocatalysis assisted with TiO2 is shown as an alternative additional technique with its own pros and cons. Further, a cursory overview of TiO2 modification techniques is made and advantages in using copper and zirconium oxides for TiO2 modification are presented. The reason and possible positive effect of using of two oxides simultaneously for TiO2 modification is indicated. Additionally, a positive impact of solar light for overall rate of dyes degradation assisted with TiO2 is discussed. Within the framework of photosensitization effect, the problem of using dyes for assessment of photocatalytic properties of materials under the visible light is touched on. Photothermal methods as possible beneficial techniques for this purpose are proposed.
In the Experimental chapter, all experimental techniques used in current research work with the technical details specific for the research work are presented. There are methods of materials preparation, photocatalytic tests under different conditions and varying model pollutants, and physico-chemical characterization techniques.
The Results and discussion chapter is divided by three subchapters. Each chapter is dedicated to one hypothesis, which was checked and confirmed or disproved. The first hypothesis is about beneficial loading of copper and zirconium oxides to TiO2. After numerous experiments held, it was concluded that the pair of copper and zirconium oxides is beneficial for simultaneous application on TiO2 surface to promote its performance.
The second subchapter is about zirconium distribution and its impact on the activity of studied materials towards the antraquinone dye Reactive Blue 19. Different techniques such as XRD, TEM, EXAFS and many others were used in order to characterize the materials and to understand the details of the processes taking place. The existence of upper limit of copper oxide loading for its beneficial effect on TiO2 performance was demonstrated. It was observed that zirconium species loading leads to improvement in performance of materials with higher copper loading, which otherwise lowers activity of TiO2 – this is in case when copper only above its optimal level is present. It was concluded that zirconium oxide containing species occupy rutile surface sites in mixed phase TiO2 and this way beneficially influence the material performance towards the dye removal.
The third subchapter is about the visible light TiO2 assisted dye degradation. It is well known that photosensitization mechanism of dye degradation appears under the visible and as a consequence under the solar light irradiation. This leads to the overall enhancement of dyes degradation, which is positive and may be used as a benefit for faster pollutant destruction. However, this fact leads to mishmash in the determination of real photocatalytic activity of materials towards the dye. It was hypothesized that the impact of photosensitization mechanism on the overall material performance against Reactive blue 19 dye (RB19) descends with the dye concentration lowering. Thermal lens spectrometry (TLS) which is sensitive to chemicals at low concentrations was used for hypothesis evaluation.
To summarize the research work achievements, the conclusions of the thesis are given at the end.
Ključne besede: titanium dioxide, photocatalysis, zirconium/copper, surface modification, water treatment, dyes
Objavljeno v RUNG: 03.12.2019; Ogledov: 7737; Prenosov: 143
 Celotno besedilo (3,18 MB) |
83. Bacterial surface display of nanobodies against cancer and toxic micoalgal cellsSandra Oloketuyi, Carina Dilkaute, Elisa Mazzega, Joachim Jose, Ario De Marco, 2019, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: bacteria surface display, nanobodies, HER2, A. minutum
Objavljeno v RUNG: 18.11.2019; Ogledov: 4103; Prenosov: 103
Celotno besedilo (12,18 KB) |
84. |
85. Synthesis of adsorbent-free ultrathin Bi2Se3 Topological Insulator Platelets and Its Inherent Surface PropertiesBlaž Belec, Katja Ferfolja, Tanja Goršak, Nina Kostevšek, Sandra Gardonio, Mattia Fanetti, Matjaž Valant, 2019, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: Bismuth selenide, topological insulator, hydrothermal synthesis, surface properties
Objavljeno v RUNG: 30.09.2019; Ogledov: 4067; Prenosov: 0
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86. Cu and Zr surface sites in photocatalytic activity of TiO [sub] 2 nanoparticles : the effect of Zr distributionOlena Pliekhova, O. L. Pliekhov, Mattia Fanetti, Iztok Arčon, Nataša Novak Tušar, Urška Lavrenčič Štangar, 2019, izvirni znanstveni članek Opis: The present work is focused on the role of ZrO2 modification in the performance of CuO modified TiO2. Zirconia
loading leads to formation of more resistant photocatalytic layers compared to samples modified with only
copper containing species. Surface modification of mixed phase TiO2 with CuO/ZrO2 improves the degradation
of Reactive blue 19 dye under simulated solar irradiation. An in-depth investigation of the catalysts showed that
in case of CuO/ZrO2 modification, the covering of the TiO2 surface with zirconium containing species prevents
morphological and harmful energetic changes induced by copper species formed on the rutile TiO2 phase at a
higher copper loading.
Ključne besede: titanium dioxide, surface modification, XAS analysis, surface acidity, Hammett indicators
Objavljeno v RUNG: 26.03.2019; Ogledov: 3811; Prenosov: 0
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87. Self-cleaning and photoactive TiO2 – ZrO2 – SiO2 films on thermosensitive and glass substratesNives Vodišek, Urška Lavrenčič Štangar, 2017, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Nanosized TiO2 is well-known for its photocatalytic property. From the combination of photocatalysis and photoinduced hydrophilicity properties, thin films of this material have also anti-fogging, self-cleaning and antimicrobial properties. There are numerous deposition techniques e.g. spin-coating, dip-coating, spraying, the most suitable one is chosen based on substrate or solution characteristics. Thin films are often required to be transparent for visible light, especially if we use them on transparent substrates, or they should not affect the color of the substrate. Radicals that are produced during photosensitizing process are able to destroy structure of a substrate and substrate can lose mechanical stability [1,2]. Some studies show that adding a SiO2 protective layer can prevent the damage of the substrate [3–5]. Ti-Zr containing sols were prepared with sol-gel process, where titanium(IV) isopropoxide, zirconium(IV) butoxide and ethanol were hydrolyzed with aqueous solution of perchloric acid. Solution was then refluxed for 48 hours. During that time crystallization and deaggregation took place and that resulted in a stable final solution [6]. To prepare suitable solution for production of durable films silica binder was added. On glass and plastic substrates, thin films were deposited with the dip-coating method and dried with a heat-gun. Thin films were characterized by measurements of photocatalytic activity with terephthalic acid as model organic pollutant subjected to oxidation via fluorescent degradation product, photoinduced superhydrophilicity phenomena, UV-Vis and ATR-FTIR spectroscopy, SEM images, as well as mechanical properties measurements.
References
[1] H. Schmidt, M. Naumann, T.S. Müller, M. Akarsu, Thin Solid Films (2006) 502, 132– 137.
[2] W. A. Daoud, J.H. Xin, Y.H. Zhang, Surf. Sci. (2005) 599, 69–75.
[3] Ž. Senić, S. Bauk, M. Vitorović-Todorović, N. Pajić, A. Samolov, D. Rajić, Sci. Tech. Rev. (2011) 61, 63–72.
[4] T. Yuranova, R. Mosteo, J. Bandara, D. Laub, J. Kiwi, J. Mol. Catal. A: Chem. (2006) 244, 160–167.
[5] T. Yuranova, D. Laub, J. Kiwi, Catal. Today (2007) 122, 109–117.
[6] N. Vodišek, K. Ramanujachary, V. Brezová, U. Lavrenčič Štangar, Catal. Today (2017) 287, 142–147.
Ključne besede: Self-cleaning surface, photocatalysis, TiO2, ZrO2, SiO2, PVC, PMMA, thermosensitive substrates, glass
Objavljeno v RUNG: 05.03.2019; Ogledov: 4365; Prenosov: 0
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88. |
89. Transparent Photocatalytic Thin Films on Flexible Polymer SubstratesNives Vodišek, Andraž Šuligoj, Dorota Korte, Urška Lavrenčič Štangar, 2018, izvirni znanstveni članek Ključne besede: photocatalysis, self-cleaning surface, TiO2, ZrO2, SiO2, transparent films, thermosensitive
substrates, PMMA, PVC, PES, PVDF
Objavljeno v RUNG: 19.10.2018; Ogledov: 4192; Prenosov: 152
Celotno besedilo (4,37 MB) |
90. The effect of Zr loading on photocatalytic activity of Cu modified TiO2Olena Pliekhova, O. L. Pliekhov, Mattia Fanetti, Iztok Arčon, Nataša Novak Tušar, Urška Lavrenčič Štangar, 2018, objavljeni znanstveni prispevek na konferenci Ključne besede: Titanium diokside, acidic sites, surface titration, copper, zirconium
Objavljeno v RUNG: 10.09.2018; Ogledov: 4594; Prenosov: 0
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