TY  - JOUR
AU  - Đorđević, Vesna R.
AU  - Sredojević, Dušan
AU  - Dostanić, Jasmina
AU  - Lončarević, Davor
AU  - Ahrenkiel, Scott Phillip
AU  - Švrakić, Nenad M.
AU  - Brothers, Edward N.
AU  - Belić, Milivoj R.
AU  - Nedeljković, Jovan
PY  - 2019
UR  - https://linkinghub.elsevier.com/retrieve/pii/S1387181118303639
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7763
AB  - Surface modification of Al2O3 powders, prepared using reproducible sol-gel synthetic route with small colorless organic molecules, induces charge transfer complex formation and the appearance of absorption in the visible spectral region. Comprehensive microstructural characterization involving transmission electron microscopy, X-ray diffraction analysis, and nitrogen adsorption–desorption isotherms, revealed that γ-crystalline alumina powders consist of mesoporous particles in the size range from 0.1 to 0.3 μm, with specific surface area of 54.8 m2/g, and pore radius between 3 and 4 nm. The attachment of catecholate-type of ligands (catechol, caffeic acid, gallic acid, dopamine and 2,3-dihydroxy naphthalene), salicylate-type of ligands (salicylic acid and 5-amino salicylic acid), and ascorbic acid, to the surface such γ-Al2O3 particles leads to the formation of colored powders and activates their absorption in visible-light spectral region. To the best of our knowledge, similar transformation of an insulator (Al2O3), with the band gap energy of 8.7 eV, into a semiconductor-like hybrid material with tunable optical properties has not been reported in the literature before. The density functional theory (DFT) calculations with periodic boundary conditions were performed in order to estimate the energy gaps of various inorganic/organic hybrids. The calculated values compare well with the experimental data. The good agreement between the calculated and experimentally determined band gaps was found, thus demonstrating predictive ability of the theory when proper model is used.
T2  - Microporous and Mesoporous Materials
T1  - Visible light absorption of surface-modified Al2O3 powders: A comparative DFT and experimental study
VL  - 273
SP  - 41
EP  - 49
DO  - 10.1016/j.micromeso.2018.06.053
ER  - 

@article{
author = "Đorđević, Vesna R. and Sredojević, Dušan and Dostanić, Jasmina and Lončarević, Davor and Ahrenkiel, Scott Phillip and Švrakić, Nenad M. and Brothers, Edward N. and Belić, Milivoj R. and Nedeljković, Jovan",
year = "2019",
abstract = "Surface modification of Al2O3 powders, prepared using reproducible sol-gel synthetic route with small colorless organic molecules, induces charge transfer complex formation and the appearance of absorption in the visible spectral region. Comprehensive microstructural characterization involving transmission electron microscopy, X-ray diffraction analysis, and nitrogen adsorption–desorption isotherms, revealed that γ-crystalline alumina powders consist of mesoporous particles in the size range from 0.1 to 0.3 μm, with specific surface area of 54.8 m2/g, and pore radius between 3 and 4 nm. The attachment of catecholate-type of ligands (catechol, caffeic acid, gallic acid, dopamine and 2,3-dihydroxy naphthalene), salicylate-type of ligands (salicylic acid and 5-amino salicylic acid), and ascorbic acid, to the surface such γ-Al2O3 particles leads to the formation of colored powders and activates their absorption in visible-light spectral region. To the best of our knowledge, similar transformation of an insulator (Al2O3), with the band gap energy of 8.7 eV, into a semiconductor-like hybrid material with tunable optical properties has not been reported in the literature before. The density functional theory (DFT) calculations with periodic boundary conditions were performed in order to estimate the energy gaps of various inorganic/organic hybrids. The calculated values compare well with the experimental data. The good agreement between the calculated and experimentally determined band gaps was found, thus demonstrating predictive ability of the theory when proper model is used.",
journal = "Microporous and Mesoporous Materials",
title = "Visible light absorption of surface-modified Al2O3 powders: A comparative DFT and experimental study",
volume = "273",
pages = "41-49",
doi = "10.1016/j.micromeso.2018.06.053"
}

Đorđević, V. R., Sredojević, D., Dostanić, J., Lončarević, D., Ahrenkiel, S. P., Švrakić, N. M., Brothers, E. N., Belić, M. R.,& Nedeljković, J.. (2019). Visible light absorption of surface-modified Al2O3 powders: A comparative DFT and experimental study. in Microporous and Mesoporous Materials, 273, 41-49.
https://doi.org/10.1016/j.micromeso.2018.06.053

Đorđević VR, Sredojević D, Dostanić J, Lončarević D, Ahrenkiel SP, Švrakić NM, Brothers EN, Belić MR, Nedeljković J. Visible light absorption of surface-modified Al2O3 powders: A comparative DFT and experimental study. in Microporous and Mesoporous Materials. 2019;273:41-49.
doi:10.1016/j.micromeso.2018.06.053 .

Đorđević, Vesna R., Sredojević, Dušan, Dostanić, Jasmina, Lončarević, Davor, Ahrenkiel, Scott Phillip, Švrakić, Nenad M., Brothers, Edward N., Belić, Milivoj R., Nedeljković, Jovan, "Visible light absorption of surface-modified Al2O3 powders: A comparative DFT and experimental study" in Microporous and Mesoporous Materials, 273 (2019):41-49,
https://doi.org/10.1016/j.micromeso.2018.06.053 . .

TY  - JOUR
AU  - Đorđević, Vesna R.
AU  - Dostanić, Jasmina
AU  - Lončarević, Davor
AU  - Ahrenkiel, Scott Phillip
AU  - Sredojević, Dušan
AU  - Švrakić, Nenad M.
AU  - Belić, Milivoj R.
AU  - Nedeljković, Jovan
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1723
AB  - Detailed study of Al2O3, an insulator with the band gap of about 8.7 eV, and its different organic/inorganic charge transfer complexes with visible-light photo activity is presented. In particular, prepared Al2O3 particles of the size 0.1-0.3 mu m are coated with several organic complexes - the specific details for catecholate- and salicylate-type of ligands are described below - and the light absorption properties and photocatalytic activity of such hybrids are scrutinized and compared with those of other organic/inorganic hybrid materials previously studied. In addition, the obtained experimental results are supported with quantum chemical calculations based on density functional theory. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Chemical Physics Letters
T1  - Hybrid visible-light responsive Al2O3 particles
VL  - 685
SP  - 416
EP  - 421
DO  - 10.1016/j.cplett.2017.08.012
ER  - 

@article{
author = "Đorđević, Vesna R. and Dostanić, Jasmina and Lončarević, Davor and Ahrenkiel, Scott Phillip and Sredojević, Dušan and Švrakić, Nenad M. and Belić, Milivoj R. and Nedeljković, Jovan",
year = "2017",
abstract = "Detailed study of Al2O3, an insulator with the band gap of about 8.7 eV, and its different organic/inorganic charge transfer complexes with visible-light photo activity is presented. In particular, prepared Al2O3 particles of the size 0.1-0.3 mu m are coated with several organic complexes - the specific details for catecholate- and salicylate-type of ligands are described below - and the light absorption properties and photocatalytic activity of such hybrids are scrutinized and compared with those of other organic/inorganic hybrid materials previously studied. In addition, the obtained experimental results are supported with quantum chemical calculations based on density functional theory. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Chemical Physics Letters",
title = "Hybrid visible-light responsive Al2O3 particles",
volume = "685",
pages = "416-421",
doi = "10.1016/j.cplett.2017.08.012"
}

Đorđević, V. R., Dostanić, J., Lončarević, D., Ahrenkiel, S. P., Sredojević, D., Švrakić, N. M., Belić, M. R.,& Nedeljković, J.. (2017). Hybrid visible-light responsive Al2O3 particles. in Chemical Physics Letters, 685, 416-421.
https://doi.org/10.1016/j.cplett.2017.08.012

Đorđević VR, Dostanić J, Lončarević D, Ahrenkiel SP, Sredojević D, Švrakić NM, Belić MR, Nedeljković J. Hybrid visible-light responsive Al2O3 particles. in Chemical Physics Letters. 2017;685:416-421.
doi:10.1016/j.cplett.2017.08.012 .

Đorđević, Vesna R., Dostanić, Jasmina, Lončarević, Davor, Ahrenkiel, Scott Phillip, Sredojević, Dušan, Švrakić, Nenad M., Belić, Milivoj R., Nedeljković, Jovan, "Hybrid visible-light responsive Al2O3 particles" in Chemical Physics Letters, 685 (2017):416-421,
https://doi.org/10.1016/j.cplett.2017.08.012 . .

TY  - JOUR
AU  - Milićević, Bojana R.
AU  - Đorđević, Vesna R.
AU  - Lončarević, Davor
AU  - Dostanić, Jasmina
AU  - Ahrenkiel, Scott Phillip
AU  - Dramićanin, Miroslav
AU  - Sredojević, Dušan
AU  - Švrakić, Nenad M.
AU  - Nedeljković, Jovan
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1815
AB  - Under normal conditions, titanium dioxide does not absorb visible light photons due to large band gap. Nevertheless, when titanium dioxide nanoparticles (TiO2 NPs) are surface-modified with thiosalicylic acid (TSA), their optical properties are altered owing to the formation of charge transfer complex that initiates absorption in the visible spectral range. Colloidal and sol-gel techniques were used to synthesize uniform TiO2 NPs of different sizes (average diameters in the range 4-15 nm), and effects of their subsequent modification by TSA molecules were compared with effect of modification of commercial Degussa TiO2 powder. Thorough microstructural characterization of TiO2 nanoparticulates was performed including transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis, as well as nitrogen adsorption-desorption isotherms. Optical measurements revealed that all surface-modified TiO2 samples with TSA have similar spectral features independent of their morphological differences, and, more importantly, absorption onset of modified TiO2 samples was found to be red-shifted by 1.0 eV compared to the unmodified ones. The mode of binding between TSA and surface Ti atoms was analyzed by infrared spectroscopy. Finally, the quantum chemical calculations, based on density functional theory, were performed to support optical characterization of surface-modified TiO2 with TSA. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Optical Materials
T1  - Charge-transfer complex formation between TiO2 nanoparticles and thiosalicylic acid: A comprehensive experimental and DFT study
VL  - 73
SP  - 163
EP  - 171
DO  - 10.1016/j.optmat.2017.08.011
ER  - 

@article{
author = "Milićević, Bojana R. and Đorđević, Vesna R. and Lončarević, Davor and Dostanić, Jasmina and Ahrenkiel, Scott Phillip and Dramićanin, Miroslav and Sredojević, Dušan and Švrakić, Nenad M. and Nedeljković, Jovan",
year = "2017",
abstract = "Under normal conditions, titanium dioxide does not absorb visible light photons due to large band gap. Nevertheless, when titanium dioxide nanoparticles (TiO2 NPs) are surface-modified with thiosalicylic acid (TSA), their optical properties are altered owing to the formation of charge transfer complex that initiates absorption in the visible spectral range. Colloidal and sol-gel techniques were used to synthesize uniform TiO2 NPs of different sizes (average diameters in the range 4-15 nm), and effects of their subsequent modification by TSA molecules were compared with effect of modification of commercial Degussa TiO2 powder. Thorough microstructural characterization of TiO2 nanoparticulates was performed including transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis, as well as nitrogen adsorption-desorption isotherms. Optical measurements revealed that all surface-modified TiO2 samples with TSA have similar spectral features independent of their morphological differences, and, more importantly, absorption onset of modified TiO2 samples was found to be red-shifted by 1.0 eV compared to the unmodified ones. The mode of binding between TSA and surface Ti atoms was analyzed by infrared spectroscopy. Finally, the quantum chemical calculations, based on density functional theory, were performed to support optical characterization of surface-modified TiO2 with TSA. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Optical Materials",
title = "Charge-transfer complex formation between TiO2 nanoparticles and thiosalicylic acid: A comprehensive experimental and DFT study",
volume = "73",
pages = "163-171",
doi = "10.1016/j.optmat.2017.08.011"
}

Milićević, B. R., Đorđević, V. R., Lončarević, D., Dostanić, J., Ahrenkiel, S. P., Dramićanin, M., Sredojević, D., Švrakić, N. M.,& Nedeljković, J.. (2017). Charge-transfer complex formation between TiO2 nanoparticles and thiosalicylic acid: A comprehensive experimental and DFT study. in Optical Materials, 73, 163-171.
https://doi.org/10.1016/j.optmat.2017.08.011

Milićević BR, Đorđević VR, Lončarević D, Dostanić J, Ahrenkiel SP, Dramićanin M, Sredojević D, Švrakić NM, Nedeljković J. Charge-transfer complex formation between TiO2 nanoparticles and thiosalicylic acid: A comprehensive experimental and DFT study. in Optical Materials. 2017;73:163-171.
doi:10.1016/j.optmat.2017.08.011 .

Milićević, Bojana R., Đorđević, Vesna R., Lončarević, Davor, Dostanić, Jasmina, Ahrenkiel, Scott Phillip, Dramićanin, Miroslav, Sredojević, Dušan, Švrakić, Nenad M., Nedeljković, Jovan, "Charge-transfer complex formation between TiO2 nanoparticles and thiosalicylic acid: A comprehensive experimental and DFT study" in Optical Materials, 73 (2017):163-171,
https://doi.org/10.1016/j.optmat.2017.08.011 . .