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1.
Study of water adsorption on EDTA dealuminated zeolite Y
O. L. Pliekhov, Olena Pliekhova, Iztok Arčon, Federica Bondino, Elena Magnano, Gregor Mali, Nataša Zabukovec Logar, 2020, original scientific article

Abstract: 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.
Keywords: Zeolite Y Water sorption Dealumination Al XANES EDTA treatment
Published in RUNG: 05.06.2020; Views: 2906; Downloads: 0
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2.
Cu and Zr surface sites in photocatalytic activity of TiO [sub] 2 nanoparticles : the effect of Zr distribution
Olena Pliekhova, O. L. Pliekhov, Mattia Fanetti, Iztok Arčon, Nataša Novak Tušar, Urška Lavrenčič Štangar, 2019, original scientific article

Abstract: 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.
Keywords: titanium dioxide, surface modification, XAS analysis, surface acidity, Hammett indicators
Published in RUNG: 26.03.2019; Views: 3119; Downloads: 0
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3.
The effect of Zr loading on photocatalytic activity of Cu modified TiO [sub] 2
Olena Pliekhova, O. L. Pliekhov, Mattia Fanetti, Iztok Arčon, Nataša Novak Tušar, Urška Lavrenčič Štangar, 2018, published scientific conference contribution abstract

Keywords: Cu Zr modified TiO2, EXAFS, XANES
Published in RUNG: 12.09.2018; Views: 3350; Downloads: 0
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4.
The effect of Zr loading on photocatalytic activity of Cu modified TiO2
Olena Pliekhova, O. L. Pliekhov, Mattia Fanetti, Iztok Arčon, Nataša Novak Tušar, Urška Lavrenčič Štangar, 2018, published scientific conference contribution

Keywords: Titanium diokside, acidic sites, surface titration, copper, zirconium
Published in RUNG: 10.09.2018; Views: 3806; Downloads: 0
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5.
Photocatalytic Activity of Zirconium- and Manganese- Codoped Titania in Aqueous Media: The Role of the Metal Dopant and its Incorporation Site
O. L. Pliekhov, Iztok Arčon, Nataša Novak Tušar, Urška Lavrenčič Štangar, 2016, original scientific article

Abstract: The development of efficient TiO2-based photocatalysts for water treatment is mainly performed by doping with transition metals or by establishing junctions between different phases, metal–semiconductor or semiconductor–semiconductor. We present, for the first time, the synthesis of Zr- and Mn-modified TiO2 by a redesigned sol–gel technique that allows the formation of heterometallic bridges on the TiO2 surface. Cations of the doping metals are located in the pores of mesoporous anatase and attached to the crystalline TiO2 walls. The presence of the Zr enhances the photoactivity of the TiO2 catalyst. However, the introduction of Mn decreases the photocatalytic efficiency in a nonadditive manner. The inhibition effect was assigned to the side reaction between hydroxyl radicals and Mn ions. The fact that Mn effectively scavenges the hydroxyl radicals and, consequently, inhibits the whole oxidation process is direct proof that hydroxyl radicals are the main reactive species in the photocatalytic oxidative processes on TiO2 surfaces in aqueous media and the process of COH generation is the rate-determining step, which was confirmed using a method based on the decolorization of a commercial dye Bezaktiv Blau in a reaction with Fenton’s reagent as a source of hydroxyl radicals.
Keywords: doping, manganese, oxidation, X-ray absorption spectroscopy, zirconium
Published in RUNG: 21.07.2016; Views: 4105; Downloads: 0
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6.
Photocatalytic activity of Zr and Mn co-doped TiO2 in aqueous media
Urška Lavrenčič Štangar, O. L. Pliekhov, Nataša Novak Tušar, 2015, published scientific conference contribution abstract

Keywords: mechanism, influence of dopants, Mn scavenger of hydroxyl radicals
Published in RUNG: 01.02.2016; Views: 4883; Downloads: 1
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