Veljkovic, Ivana

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  • Veljkovic, Ivana (2)
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Author's Bibliography

Influence of Some Sol-Gel Synthesis Parameters of Mesoporous Tio2 on Photocatalytic Degradation of Pollutants

Golubović, Aleksandar V.; Veljkovic, Ivana; Scepanovic, Maja; Grujić-Brojčin, Mirjana; Tomic, Natasa; Mijin, Dušan Ž.; Babić, Biljana M.

(2016)

TY  - JOUR
AU  - Golubović, Aleksandar V.
AU  - Veljkovic, Ivana
AU  - Scepanovic, Maja
AU  - Grujić-Brojčin, Mirjana
AU  - Tomic, Natasa
AU  - Mijin, Dušan Ž.
AU  - Babić, Biljana M.
PY  - 2016
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/1020
AB  - Titanium dioxide (TiO2) nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor by varying some parameters of the sol-gel synthesis, such as temperature (500 and 550 degrees C) and the duration of calcination (1.5, 2 and 2.5 h). X-ray powder diffraction (XRPD) results have shown that all synthesized nanopowders were dominantly in the anatase phase, with the presence of a small amount of rutile in samples calcined at 550 degrees C. According to the results obtained by the Williamson-Hall method, the anatase crystallite size was increased with the duration of the calcination (from 24 to 29 nm in samples calcined at lower temperature, and from 30 to 35 nm in samples calcined at higher temperature). The analysis of the shift and line-width of the most intensive anatase Eg Raman mode confirmed the XRPD results. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 5-8 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16), car-bofuran ray scattering.
T2  - Chemical Industry and Chemical Engineering Quarterly / CICEQ
T1  - Influence of Some Sol-Gel Synthesis Parameters of Mesoporous Tio2 on Photocatalytic Degradation of Pollutants
VL  - 22
IS  - 1
SP  - 65
EP  - 73
DO  - 10.2298/CICEQ150110020G
ER  - 
@article{
author = "Golubović, Aleksandar V. and Veljkovic, Ivana and Scepanovic, Maja and Grujić-Brojčin, Mirjana and Tomic, Natasa and Mijin, Dušan Ž. and Babić, Biljana M.",
year = "2016",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/1020",
abstract = "Titanium dioxide (TiO2) nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor by varying some parameters of the sol-gel synthesis, such as temperature (500 and 550 degrees C) and the duration of calcination (1.5, 2 and 2.5 h). X-ray powder diffraction (XRPD) results have shown that all synthesized nanopowders were dominantly in the anatase phase, with the presence of a small amount of rutile in samples calcined at 550 degrees C. According to the results obtained by the Williamson-Hall method, the anatase crystallite size was increased with the duration of the calcination (from 24 to 29 nm in samples calcined at lower temperature, and from 30 to 35 nm in samples calcined at higher temperature). The analysis of the shift and line-width of the most intensive anatase Eg Raman mode confirmed the XRPD results. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 5-8 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16), car-bofuran ray scattering.",
journal = "Chemical Industry and Chemical Engineering Quarterly / CICEQ",
title = "Influence of Some Sol-Gel Synthesis Parameters of Mesoporous Tio2 on Photocatalytic Degradation of Pollutants",
volume = "22",
number = "1",
pages = "65-73",
doi = "10.2298/CICEQ150110020G"
}
Golubović, A. V., Veljkovic, I., Scepanovic, M., Grujić-Brojčin, M., Tomic, N., Mijin, D. Ž.,& Babić, B. M. (2016). Influence of Some Sol-Gel Synthesis Parameters of Mesoporous Tio2 on Photocatalytic Degradation of Pollutants.
Chemical Industry and Chemical Engineering Quarterly / CICEQ, 22(1), 65-73.
https://doi.org/10.2298/CICEQ150110020G
Golubović AV, Veljkovic I, Scepanovic M, Grujić-Brojčin M, Tomic N, Mijin DŽ, Babić BM. Influence of Some Sol-Gel Synthesis Parameters of Mesoporous Tio2 on Photocatalytic Degradation of Pollutants. Chemical Industry and Chemical Engineering Quarterly / CICEQ. 2016;22(1):65-73
Golubović Aleksandar V., Veljkovic Ivana, Scepanovic Maja, Grujić-Brojčin Mirjana, Tomic Natasa, Mijin Dušan Ž., Babić Biljana M., "Influence of Some Sol-Gel Synthesis Parameters of Mesoporous Tio2 on Photocatalytic Degradation of Pollutants" Chemical Industry and Chemical Engineering Quarterly / CICEQ, 22, no. 1 (2016):65-73,
https://doi.org/10.2298/CICEQ150110020G .
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Investigation of surface defect states in CeO2-y nanocrystals by Scanning-tunneling microscopy/spectroscopy and ellipsometry

Radović, Marko B.; Stojadinovic, Bojan; Tomic, Natasa; Golubović, Aleksandar V.; Matović, Branko; Veljkovic, Ivana; Dohcevic-Mitrovic, Zorana

(2014)

TY  - JOUR
AU  - Radović, Marko B.
AU  - Stojadinovic, Bojan
AU  - Tomic, Natasa
AU  - Golubović, Aleksandar V.
AU  - Matović, Branko
AU  - Veljkovic, Ivana
AU  - Dohcevic-Mitrovic, Zorana
PY  - 2014
UR  - http://vinar.vin.bg.ac.rs/handle/123456789/308
AB  - Synthesis process strongly influences the nanocrystalline CeO2-y defective structure. The presence of surface defects, in the form of oxygen vacancies in different charge states (F centers), can change the electronic properties of ceria nanocrystals. Nanocrystalline CeO2-y samples were synthesized using three different methods (precipitation, self-propagating room temperature, and hydrothermal synthesis). Raman spectroscopy was used to identify the presence of oxygen vacancies which presumably were formed at the nanoparticle surface. The defect concentration depended on the crystallite size of differently prepared CeO2-y samples. Scanning tunneling microscopy/spectroscopy and ellipsometry were employed to investigate the electronic band structure of defective CeO2-y nanocrystals. Scanning tunneling spectroscopy measurements demonstrated that inside the band gap of CeO2-y nanocrystals, besides the filled 4 f states, appeared additional states which were related to occupied and empty F center defect states. From the ellipsometric measurements, using the critical points model, the energy positions of different F centers states and the values of the reduced band gap energies were determined. The analysis of obtained data pointed out that depending on the synthesis method, different types of F centers (F+ and F-0) can be formed in the CeO2-y nanocrystals. The formation of different F center defect states inside the ceria gap have a strong impact on the electrical, optical, and magnetic properties of ceria nanocrystals. (C) 2014 AIP Publishing LLC.
T2  - Journal of Applied Physics
T1  - Investigation of surface defect states in CeO2-y nanocrystals by Scanning-tunneling microscopy/spectroscopy and ellipsometry
VL  - 116
IS  - 23
DO  - 10.1063/1.4904516
ER  - 
@article{
author = "Radović, Marko B. and Stojadinovic, Bojan and Tomic, Natasa and Golubović, Aleksandar V. and Matović, Branko and Veljkovic, Ivana and Dohcevic-Mitrovic, Zorana",
year = "2014",
url = "http://vinar.vin.bg.ac.rs/handle/123456789/308",
abstract = "Synthesis process strongly influences the nanocrystalline CeO2-y defective structure. The presence of surface defects, in the form of oxygen vacancies in different charge states (F centers), can change the electronic properties of ceria nanocrystals. Nanocrystalline CeO2-y samples were synthesized using three different methods (precipitation, self-propagating room temperature, and hydrothermal synthesis). Raman spectroscopy was used to identify the presence of oxygen vacancies which presumably were formed at the nanoparticle surface. The defect concentration depended on the crystallite size of differently prepared CeO2-y samples. Scanning tunneling microscopy/spectroscopy and ellipsometry were employed to investigate the electronic band structure of defective CeO2-y nanocrystals. Scanning tunneling spectroscopy measurements demonstrated that inside the band gap of CeO2-y nanocrystals, besides the filled 4 f states, appeared additional states which were related to occupied and empty F center defect states. From the ellipsometric measurements, using the critical points model, the energy positions of different F centers states and the values of the reduced band gap energies were determined. The analysis of obtained data pointed out that depending on the synthesis method, different types of F centers (F+ and F-0) can be formed in the CeO2-y nanocrystals. The formation of different F center defect states inside the ceria gap have a strong impact on the electrical, optical, and magnetic properties of ceria nanocrystals. (C) 2014 AIP Publishing LLC.",
journal = "Journal of Applied Physics",
title = "Investigation of surface defect states in CeO2-y nanocrystals by Scanning-tunneling microscopy/spectroscopy and ellipsometry",
volume = "116",
number = "23",
doi = "10.1063/1.4904516"
}
Radović, M. B., Stojadinovic, B., Tomic, N., Golubović, A. V., Matović, B., Veljkovic, I.,& Dohcevic-Mitrovic, Z. (2014). Investigation of surface defect states in CeO2-y nanocrystals by Scanning-tunneling microscopy/spectroscopy and ellipsometry.
Journal of Applied Physics, 116(23).
https://doi.org/10.1063/1.4904516
Radović MB, Stojadinovic B, Tomic N, Golubović AV, Matović B, Veljkovic I, Dohcevic-Mitrovic Z. Investigation of surface defect states in CeO2-y nanocrystals by Scanning-tunneling microscopy/spectroscopy and ellipsometry. Journal of Applied Physics. 2014;116(23)
Radović Marko B., Stojadinovic Bojan, Tomic Natasa, Golubović Aleksandar V., Matović Branko, Veljkovic Ivana, Dohcevic-Mitrovic Zorana, "Investigation of surface defect states in CeO2-y nanocrystals by Scanning-tunneling microscopy/spectroscopy and ellipsometry" Journal of Applied Physics, 116, no. 23 (2014),
https://doi.org/10.1063/1.4904516 .
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