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3. Characterization of Cu and Zr modified TiO[sub]2 photocatalysts by photothermal beam deflection spectrometryMahmoud Abdelhamid, Dorota Korte, Humberto Cabrera, Zeinab Ebrahimpour, Olena Pliekhova, Urška Lavrenčič Štangar, Mladen Franko, 2021, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: photocatalysts, TiO2, Cu/Zr, photodegradation, material characterization, photothermal spectrometry Objavljeno v RUNG: 23.11.2021; Ogledov: 3337; Prenosov: 0 Gradivo ima več datotek! Več... |
4. Thermo-optical characterization of Cu- and Zr-modified TiO[sub]2 photocatalysts by beam deflection spectrometryMahmoud Abdelhamid, Dorota Korte, Humberto Cabrera, Olena Pliekhova, Zeinab Ebrahimpour, Urška Lavrenčič Štangar, Mladen Franko, 2021, izvirni znanstveni članek Ključne besede: photocatalysts, TiO2, Cu/Zr, photodegradation, material characterization, photothermal spectrometry Objavljeno v RUNG: 23.11.2021; Ogledov: 2573; Prenosov: 100 Povezava na celotno besedilo Gradivo ima več datotek! Več... |
5. Photodegradation mechanisms of reactive blue 19 dye under UV and simulated solar light irradiationZeinab Ebrahimpour, Olena Pliekhova, Humberto Cabrera, Mahmoud Abdelhamid, Dorota Korte, Komlan Segbéya Gadedjisso-Tossou, Joseph J. Niemela, Urška Lavrenčič Štangar, Mladen Franko, 2021, izvirni znanstveni članek Ključne besede: reactive blue 19, photocatalytic, photosensitization, thermal lens, UV-Vis Objavljeno v RUNG: 02.02.2021; Ogledov: 3433; Prenosov: 0 Gradivo ima več datotek! Več... |
6. Study of water adsorption on EDTA dealuminated zeolite YO. L. Pliekhov, Olena Pliekhova, Iztok Arčon, Federica Bondino, Elena Magnano, Gregor Mali, Nataša Zabukovec Logar, 2020, izvirni znanstveni članek Opis: Zeolite Y was synthesized and modified with EDTA dealumination procedure. The modified zeolites were
analyzed by X-ray diffraction, X-ray absorption spectroscopy, chemical analysis and water adsorption measurements.
We demonstrated that dealumination with bulk organic acid such as EDTA is able to reduce the
original intense water affinity. Furthermore, it was found that dealumination with EDTA, in contrast with
steaming and HCl dealumination, provides fully controllable, predictable and secure process of Al removal from
the zeolites’ frameworks. The shift of the adsorption isotherm in the low partial pressure range represents an
interesting result for adsorption-based applications. Ključne besede: Zeolite Y
Water sorption
Dealumination
Al XANES
EDTA treatment Objavljeno v RUNG: 05.06.2020; Ogledov: 3833; Prenosov: 0 Gradivo ima več datotek! Več... |
7. 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: 8188; Prenosov: 144 Celotno besedilo (3,18 MB) |
8. 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: 4012; Prenosov: 0 Gradivo ima več datotek! Več... |
9. Photocatalytic properties of metal modified TiO2 by photothermal techniquesZeinab Ebrahimpour, Olena Pliekhova, Humberto Cabrera, Dorota Korte, Urška Lavrenčič Štangar, Mladen Franko, 2018, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: Thermal lens spectrometry, Photothermal beam deflection spectroscopy, Dye remediation, Photothermal technique, Photocatalytic degradation, Reactive Blue 19, TiO2 modification Objavljeno v RUNG: 09.11.2018; Ogledov: 4594; Prenosov: 0 Gradivo ima več datotek! Več... |
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