TY  - JOUR
AU  - Barbierikova, Zuzana
AU  - Dvoranova, Dana
AU  - Brezova, Vlasta
AU  - Džunuzović, Enis
AU  - Sredojević, Dušan
AU  - Lazić, Vesna M.
AU  - Nedeljković, Jovan
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4243
AB  - The visible-light-responsive inorganic-organic hybrid was prepared by surface modification of commercial TiO2 powder (Degussa P25) with 4-chlorophenol (4-CP). The optical absorption of the hybrid material is red-shifted compared to unmodified TiO2 powder due to the surface charge transfer complex (CTC) formation. The experimental results are supported by the density functional theory (DFT) calculations of the corresponding model cluster. The calculated electronic excitation spectrum is in agreement with the measured reflection spectrum of surface-modified TiO2 powder with 4-CP. The paramagnetic species, generated in the unmodified and surface modified TiO2 powders upon excitation with ultraviolet and visible light, were identified using low-temperature electron paramagnetic resonance (EPR) spectroscopy. The formation of trapped electrons (Ti(III) centers) and the persistent oxygen-centered organic radicals indicated the photoinduced electron transfer from the chemisorbed 4-chlorophenol to the conduction band of TiO2.
PB  - Elsevier, Amsterdam
T2  - Optical Materials
T1  - Visible-light-responsive surface-modified TiO2 powder with 4-chlorophenol: A combined experimental and DFT study
EP  - 242
SP  - 237
VL  - 89
DO  - 10.1016/j.optmat.2019.01.027
ER  - 

@article{
author = "Barbierikova, Zuzana and Dvoranova, Dana and Brezova, Vlasta and Džunuzović, Enis and Sredojević, Dušan and Lazić, Vesna M. and Nedeljković, Jovan",
year = "2019",
abstract = "The visible-light-responsive inorganic-organic hybrid was prepared by surface modification of commercial TiO2 powder (Degussa P25) with 4-chlorophenol (4-CP). The optical absorption of the hybrid material is red-shifted compared to unmodified TiO2 powder due to the surface charge transfer complex (CTC) formation. The experimental results are supported by the density functional theory (DFT) calculations of the corresponding model cluster. The calculated electronic excitation spectrum is in agreement with the measured reflection spectrum of surface-modified TiO2 powder with 4-CP. The paramagnetic species, generated in the unmodified and surface modified TiO2 powders upon excitation with ultraviolet and visible light, were identified using low-temperature electron paramagnetic resonance (EPR) spectroscopy. The formation of trapped electrons (Ti(III) centers) and the persistent oxygen-centered organic radicals indicated the photoinduced electron transfer from the chemisorbed 4-chlorophenol to the conduction band of TiO2.",
publisher = "Elsevier, Amsterdam",
journal = "Optical Materials",
title = "Visible-light-responsive surface-modified TiO2 powder with 4-chlorophenol: A combined experimental and DFT study",
pages = "242-237",
volume = "89",
doi = "10.1016/j.optmat.2019.01.027"
}

Barbierikova, Z., Dvoranova, D., Brezova, V., Džunuzović, E., Sredojević, D., Lazić, V. M.,& Nedeljković, J.. (2019). Visible-light-responsive surface-modified TiO2 powder with 4-chlorophenol: A combined experimental and DFT study. in Optical Materials
Elsevier, Amsterdam., 89, 237-242.
https://doi.org/10.1016/j.optmat.2019.01.027

Barbierikova Z, Dvoranova D, Brezova V, Džunuzović E, Sredojević D, Lazić VM, Nedeljković J. Visible-light-responsive surface-modified TiO2 powder with 4-chlorophenol: A combined experimental and DFT study. in Optical Materials. 2019;89:237-242.
doi:10.1016/j.optmat.2019.01.027 .

Barbierikova, Zuzana, Dvoranova, Dana, Brezova, Vlasta, Džunuzović, Enis, Sredojević, Dušan, Lazić, Vesna M., Nedeljković, Jovan, "Visible-light-responsive surface-modified TiO2 powder with 4-chlorophenol: A combined experimental and DFT study" in Optical Materials, 89 (2019):237-242,
https://doi.org/10.1016/j.optmat.2019.01.027 . .

TY  - JOUR
AU  - Miljković, Miona
AU  - Lazić, Vesna M.
AU  - Banjanac, Katarina
AU  - Davidović, Slađana
AU  - Bezbradica, Dejan
AU  - Marinković, Aleksandar
AU  - Sredojević, Dušan
AU  - Nedeljković, Jovan
AU  - Dimitrijević-Branković, Suzana
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4014
AB  - The TiO2 based hybrid supports with different functional groups (amino, glutaraldehyde or epoxy) were prepared and their influence on immobilization of dextransucrase (DS) was studied. Novel synthetic route for surface modification of TiO2 with amino and glutaraldehyde groups was developed taking advantage of charge transfer complex (CTC) formation between surface Ti atoms and salicylate-type of ligand (5 aminosalicylic acid (5-ASA)). The proposed coordination of 5-ASA to the surface of TiO2 powder and optical properties of CTC was presented. The pristine TiO2 and amino functionalized TiO2 have higher sorption capacity for DS (12.6 and 12.0 mg g(-1), respectively) compared to glutaraldehyde and epoxy activated supports (9.6 and 9.8 mg g(-1) respectively). However, immobilized enzyme to either glutaraldehyde or epoxy functionalized TiO2 have almost two times higher expressed activities compared to pristine TiO2 support (258, 235 and 142 IU g(-1), respectively). Thermal stability of enzyme immobilized on glutaraldehyde and epoxy functionalized supports was studied at 40 degrees C, as well as operational stability under long-run working conditions in repeated cycles. After five cycles, DS imobilized on glutaraldehyde activated support retained almost 70% of its initial expressed activity, while, after five cycles, performance of DS immobilized on epoxy activated support was significantly lower (15%).
PB  - Elsevier Science Bv, Amsterdam
T2  - International Journal of Biological Macromolecules
T1  - Immobilization of dextransucrase on functionalized TiO2 supports
EP  - 1223
SP  - 1216
VL  - 114
DO  - 10.1016/j.ijbiomac.2018.04.027
ER  - 

@article{
author = "Miljković, Miona and Lazić, Vesna M. and Banjanac, Katarina and Davidović, Slađana and Bezbradica, Dejan and Marinković, Aleksandar and Sredojević, Dušan and Nedeljković, Jovan and Dimitrijević-Branković, Suzana",
year = "2018",
abstract = "The TiO2 based hybrid supports with different functional groups (amino, glutaraldehyde or epoxy) were prepared and their influence on immobilization of dextransucrase (DS) was studied. Novel synthetic route for surface modification of TiO2 with amino and glutaraldehyde groups was developed taking advantage of charge transfer complex (CTC) formation between surface Ti atoms and salicylate-type of ligand (5 aminosalicylic acid (5-ASA)). The proposed coordination of 5-ASA to the surface of TiO2 powder and optical properties of CTC was presented. The pristine TiO2 and amino functionalized TiO2 have higher sorption capacity for DS (12.6 and 12.0 mg g(-1), respectively) compared to glutaraldehyde and epoxy activated supports (9.6 and 9.8 mg g(-1) respectively). However, immobilized enzyme to either glutaraldehyde or epoxy functionalized TiO2 have almost two times higher expressed activities compared to pristine TiO2 support (258, 235 and 142 IU g(-1), respectively). Thermal stability of enzyme immobilized on glutaraldehyde and epoxy functionalized supports was studied at 40 degrees C, as well as operational stability under long-run working conditions in repeated cycles. After five cycles, DS imobilized on glutaraldehyde activated support retained almost 70% of its initial expressed activity, while, after five cycles, performance of DS immobilized on epoxy activated support was significantly lower (15%).",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "International Journal of Biological Macromolecules",
title = "Immobilization of dextransucrase on functionalized TiO2 supports",
pages = "1223-1216",
volume = "114",
doi = "10.1016/j.ijbiomac.2018.04.027"
}

Miljković, M., Lazić, V. M., Banjanac, K., Davidović, S., Bezbradica, D., Marinković, A., Sredojević, D., Nedeljković, J.,& Dimitrijević-Branković, S.. (2018). Immobilization of dextransucrase on functionalized TiO2 supports. in International Journal of Biological Macromolecules
Elsevier Science Bv, Amsterdam., 114, 1216-1223.
https://doi.org/10.1016/j.ijbiomac.2018.04.027

Miljković M, Lazić VM, Banjanac K, Davidović S, Bezbradica D, Marinković A, Sredojević D, Nedeljković J, Dimitrijević-Branković S. Immobilization of dextransucrase on functionalized TiO2 supports. in International Journal of Biological Macromolecules. 2018;114:1216-1223.
doi:10.1016/j.ijbiomac.2018.04.027 .

Miljković, Miona, Lazić, Vesna M., Banjanac, Katarina, Davidović, Slađana, Bezbradica, Dejan, Marinković, Aleksandar, Sredojević, Dušan, Nedeljković, Jovan, Dimitrijević-Branković, Suzana, "Immobilization of dextransucrase on functionalized TiO2 supports" in International Journal of Biological Macromolecules, 114 (2018):1216-1223,
https://doi.org/10.1016/j.ijbiomac.2018.04.027 . .

TY  - JOUR
AU  - Kovač, Tijana
AU  - Džunuzović, Enis
AU  - Džunuzović, Jasna
AU  - Milićević, Bojana R.
AU  - Sredojević, Dušan
AU  - Brothers, Edward N.
AU  - Nedeljković, Jovan
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3865
AB  - Surface modification of titanium dioxide nanoparticles (TiO2 NPs) with the biologically active molecule pyridoxine hydrochloride (vitamin B-6) was found to alter the optical properties. Microstructural characterization involving transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis revealed that the anatase TiO2 NPs had a narrow size distribution with an average diameter of 45 angstrom. The absorption onset of the surface-modified TiO2 samples was red-shifted by about 0.4 eV compared to the unmodified particles. The mode of binding between vitamin B-6 and the surface Ti atoms was investigated by Fourier transform infrared spectroscopy (FTIR). From the Benesi-Hildebrand plot, the stability constant of the surface complex was found to be of the order 10(2) M-1. The experimental findings were supported by detailed quantum chemical calculations based on the density functional theory (DFT). Agreement was found between the experimentally measured absorption spectra of the TiO2 NPs surface-modified with vitamin B-6 and the theoretically calculated electronic excitation spectra of the corresponding model system.
PB  - Srpsko hemijsko društvo, Beograd
T2  - Journal of the Serbian Chemical Society
T1  - Visible light absorption of TiO2 nanoparticles surface-modified with vitamin B-6: A comparative experimental and DFT study
EP  - 909
IS  - 7-8
SP  - 899
VL  - 83
DO  - 10.2298/JSC180131044K
ER  - 

@article{
author = "Kovač, Tijana and Džunuzović, Enis and Džunuzović, Jasna and Milićević, Bojana R. and Sredojević, Dušan and Brothers, Edward N. and Nedeljković, Jovan",
year = "2018",
abstract = "Surface modification of titanium dioxide nanoparticles (TiO2 NPs) with the biologically active molecule pyridoxine hydrochloride (vitamin B-6) was found to alter the optical properties. Microstructural characterization involving transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis revealed that the anatase TiO2 NPs had a narrow size distribution with an average diameter of 45 angstrom. The absorption onset of the surface-modified TiO2 samples was red-shifted by about 0.4 eV compared to the unmodified particles. The mode of binding between vitamin B-6 and the surface Ti atoms was investigated by Fourier transform infrared spectroscopy (FTIR). From the Benesi-Hildebrand plot, the stability constant of the surface complex was found to be of the order 10(2) M-1. The experimental findings were supported by detailed quantum chemical calculations based on the density functional theory (DFT). Agreement was found between the experimentally measured absorption spectra of the TiO2 NPs surface-modified with vitamin B-6 and the theoretically calculated electronic excitation spectra of the corresponding model system.",
publisher = "Srpsko hemijsko društvo, Beograd",
journal = "Journal of the Serbian Chemical Society",
title = "Visible light absorption of TiO2 nanoparticles surface-modified with vitamin B-6: A comparative experimental and DFT study",
pages = "909-899",
number = "7-8",
volume = "83",
doi = "10.2298/JSC180131044K"
}

Kovač, T., Džunuzović, E., Džunuzović, J., Milićević, B. R., Sredojević, D., Brothers, E. N.,& Nedeljković, J.. (2018). Visible light absorption of TiO2 nanoparticles surface-modified with vitamin B-6: A comparative experimental and DFT study. in Journal of the Serbian Chemical Society
Srpsko hemijsko društvo, Beograd., 83(7-8), 899-909.
https://doi.org/10.2298/JSC180131044K

Kovač T, Džunuzović E, Džunuzović J, Milićević BR, Sredojević D, Brothers EN, Nedeljković J. Visible light absorption of TiO2 nanoparticles surface-modified with vitamin B-6: A comparative experimental and DFT study. in Journal of the Serbian Chemical Society. 2018;83(7-8):899-909.
doi:10.2298/JSC180131044K .

Kovač, Tijana, Džunuzović, Enis, Džunuzović, Jasna, Milićević, Bojana R., Sredojević, Dušan, Brothers, Edward N., Nedeljković, Jovan, "Visible light absorption of TiO2 nanoparticles surface-modified with vitamin B-6: A comparative experimental and DFT study" in Journal of the Serbian Chemical Society, 83, no. 7-8 (2018):899-909,
https://doi.org/10.2298/JSC180131044K . .

TY  - JOUR
AU  - Sredojević, Dušan
AU  - Kovač, Tijana
AU  - Džunuzović, Enis
AU  - Đorđević, Vesna R.
AU  - Grgur, Branimir
AU  - Nedeljković, Jovan
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3537
AB  - The charge transfer complex formation between TiO2 powder and variety of phenol derivatives (phenol, 4-nitrophenol, 4-bromophenol, 4-tert-butylphenol, hydroquinone) was achieved. The red-shift of optical absorption was observed upon surface modification of TiO2 powders with phenol derivatives. The influence of substituent functional groups in para position on the optical band gap and conduction band edge of inorganic/organic hybrids was studied using reflection spectroscopy and cyclic voltammetry. The experimental findings were supported by density functional theory calculations. The measured reflection spectra of surface-modified TiO2 powders with phenol derivatives were compared with calculated electronic excitation spectra of corresponding model systems.
PB  - Elsevier, Amsterdam
T2  - Chemical Physics Letters
T1  - Surface-modified TiO2 powders with phenol derivatives: A comparative DFT and experimental study
EP  - 172
SP  - 167
VL  - 686
DO  - 10.1016/j.cplett.2017.08.023
ER  - 

@article{
author = "Sredojević, Dušan and Kovač, Tijana and Džunuzović, Enis and Đorđević, Vesna R. and Grgur, Branimir and Nedeljković, Jovan",
year = "2017",
abstract = "The charge transfer complex formation between TiO2 powder and variety of phenol derivatives (phenol, 4-nitrophenol, 4-bromophenol, 4-tert-butylphenol, hydroquinone) was achieved. The red-shift of optical absorption was observed upon surface modification of TiO2 powders with phenol derivatives. The influence of substituent functional groups in para position on the optical band gap and conduction band edge of inorganic/organic hybrids was studied using reflection spectroscopy and cyclic voltammetry. The experimental findings were supported by density functional theory calculations. The measured reflection spectra of surface-modified TiO2 powders with phenol derivatives were compared with calculated electronic excitation spectra of corresponding model systems.",
publisher = "Elsevier, Amsterdam",
journal = "Chemical Physics Letters",
title = "Surface-modified TiO2 powders with phenol derivatives: A comparative DFT and experimental study",
pages = "172-167",
volume = "686",
doi = "10.1016/j.cplett.2017.08.023"
}

Sredojević, D., Kovač, T., Džunuzović, E., Đorđević, V. R., Grgur, B.,& Nedeljković, J.. (2017). Surface-modified TiO2 powders with phenol derivatives: A comparative DFT and experimental study. in Chemical Physics Letters
Elsevier, Amsterdam., 686, 167-172.
https://doi.org/10.1016/j.cplett.2017.08.023

Sredojević D, Kovač T, Džunuzović E, Đorđević VR, Grgur B, Nedeljković J. Surface-modified TiO2 powders with phenol derivatives: A comparative DFT and experimental study. in Chemical Physics Letters. 2017;686:167-172.
doi:10.1016/j.cplett.2017.08.023 .

Sredojević, Dušan, Kovač, Tijana, Džunuzović, Enis, Đorđević, Vesna R., Grgur, Branimir, Nedeljković, Jovan, "Surface-modified TiO2 powders with phenol derivatives: A comparative DFT and experimental study" in Chemical Physics Letters, 686 (2017):167-172,
https://doi.org/10.1016/j.cplett.2017.08.023 . .