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21.
Surface modified titanium dioxide using transition metals : nickel as a winning transition metal for solar light photocatalysis
Andraž Šuligoj, Iztok Arčon, Matjaž Mazaj, Goran Dražić, Denis Arčon, Pegie Cool, Urška Lavrenčič Štangar, Nataša Novak Tušar, 2018, original scientific article

Abstract: Titanium dioxide has been widely used as an antimicrobial agent, UV-filter and catalyst for pollution abatement. Herein, surface modifications with selected transition metals (Me) over colloidal TiO2 nanoparticles and immobilization with a colloidal SiO2 binder as composite films (MeTiO2/SiO2) on a glass carrier were used to enhance solar-light photoactivity. Colloidal TiO2 nanoparticles were modified by loading selected transition metals (Me ¼ Mn, Fe, Co, Ni, Cu, and Zn) in the form of chlorides on their surface. They were present primarily as oxo-nanoclusters and a portion as metal oxides. The structural characteristics of bare TiO2 were preserved up to an optimal metal loading of 0.5 wt%. We have shown in situ that metal-oxo-nanoclusters with a redox potential close to that of O2/O2 were able to function as co-catalysts on the TiO2 surface which was excited by solar-light irradiation. The materials were tested for photocatalytic activity by two opposite methods; one detecting O2 (reduction, Rz ink test) while the other detecting OH (oxidation, terephthalic acid test). It was shown that the enhancement of the solar-light activity of TiO2 by the deposition of transition metal oxo-nanoclusters on the surface depends strongly on the combination of the reduction potential of such species and appropriate band positions of their oxides. The latter prevented excessive self-recombination of the photogenerated charge carriers by the nanoclusters in Ni and Zn modification, which was probably the case in other metal modifications. Overall, only Ni modification had a positive effect on solar photoactivity in both oxidation and reduction reactions.
Keywords: surface modified TiO2, XANES, EXAFS, Nickel, solar light photocatalyst
Published in RUNG: 01.06.2018; Views: 3820; Downloads: 0
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22.
23.
Vpliv notranjih in zunanjih okoljskih dejavnikov na nastanek virusov HPV
Jana Sitar, 2017, undergraduate thesis

Abstract: Humani virusi papiloma so eden najpogostejših vzrokov spolno prenosljivih bolezni in nastanka nekaterih vrst raka, kot so rak materničnega vratu, rakava obolenja na spolovilih ter rak glave in vratu. V diplomskem delu smo ugotavljali vpliv notranjih in zunanjih dejavnikov na nastanek in infektivnost virusov HPV-16, določali pa smo tudi strukturne lastnosti virusnega plašča. Kot notranji dejavnik smo uporabili gostiteljski protein SNX17, ki je ključen za okužbo HPV, kot zunanji dejavnik pa nanodelce titanovega dioksida, ki so pogosta sestavina kozmetičnih izdelkov. Pri pridobivanju virusnih delcev HPV-16 v celični liniji 293TT smo ugotovili, da protein SNX17 in nanodelci TiO2 ne vplivajo na količino virusnih delcev, vplivajo pa na njihovo infektivnost. Potrdili smo, da je protein SNX17 ključnega pomena za okužbo HPV, saj so imeli mutirani virusni delci AA2 bistveno zmanjšano stopnjo okužbe. Podobno smo ugotovili pri uporabi nanodelcev TiO2, kjer je bil upad infektivnosti sorazmeren koncentraciji uporabljenih nanodelcev med fazo nastanka virusnih delcev. Pri strukturnih lastnostih virusnega plašča smo analizirali količino in vrsto vključene reporterske DNA, stabilnost plašča in razmerje proteinov L1 : L2 v plašču. Ugotovili smo, da vezava plaščnega proteina L2 s SNX17 in prisotnost nanodelcev TiO2 na te lastnosti ne vplivata. Zaključili smo, da izbrani okoljski dejavniki, protein SNX17 in nanodelci TiO2 ne vplivajo na osnovne značilnosti nastanka virusnih delcev HPV-16, vplivajo pa na njihovo učinkovitost okužbe gostiteljskih celic.
Keywords: HPV, plaščni proteini, okužba, TiO2, SNX17
Published in RUNG: 17.11.2017; Views: 6817; Downloads: 242
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24.
25.
Structural analysis of sunlight efficient Cu and Zr modified TiO2 photocatalyst
Olena Pliekhova, Iztok Arčon, Urška Lavrenčič Štangar, 2017, published scientific conference contribution abstract

Keywords: TiO2, photocatalysis, EXAFS, surface modification
Published in RUNG: 23.08.2017; Views: 4573; Downloads: 0
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26.
Zr and Cu modified TiO2 photocatalysts for water treatment
Olena Pliekhova, Urška Lavrenčič Štangar, 2016, published scientific conference contribution abstract

Keywords: TiO2, water treatment, surface modification
Published in RUNG: 23.08.2017; Views: 4882; Downloads: 0
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27.
28.
Correlations between photocatalytic activity and Cu structure in Cu-modified TiO2-SiO2
T. Čižmar, published scientific conference contribution abstract

Keywords: Titanium dioxide, Cu-modified, TiO2-SiO2, photocatalysts, photocatalytic activity, Cu K-edge XANES, EXAFS
Published in RUNG: 26.06.2017; Views: 5566; Downloads: 0
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29.
Transparent titania-zirconia thin films for self-cleaning and photocatalytic application
Nives Vodišek, Kandalam Ramanujachary, Vlasta Brezová, Urška Lavrenčič Štangar, 2016, published scientific conference contribution abstract

Abstract: Thin films were prepared by sol-gel process, where different amount of zirconia were added to titania. Photocatalytic activity of thin films was measured by two methods i) determination of degradation ration of methyl stearate with measuring the contact angle and ii) formation of hydroxyterephthalic acid was measured by spectrofluorometer. Prepared samples were characterized by UV-Vis spectrophotometer, SEM, XRD, FT-IR ATR, and BET. The result of measurements of photocatalytic activity shows that the highest activity has a sample without addition of zirconia, but mechanical stability of that sample is worse.
Keywords: photocatalysis, ZrO2/ TiO2, thin films, self-cleaning, low-temperature, sol-gel process
Published in RUNG: 14.03.2017; Views: 5413; Downloads: 203
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30.
Transparent titania-zirconia-silica thin films for self-cleaning and photocatalytic applications
Nives Vodišek, Kandalam Ramanujachary, Vlasta Brezova, Urška Lavrenčič Štangar, 2017, published scientific conference contribution

Keywords: TiO2, ZrO2, thin films, photocatalysis, mechanical stability
Published in RUNG: 13.03.2017; Views: 5368; Downloads: 5
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