TY  - JOUR
AU  - Maletić, Marina M.
AU  - Kalijadis, Ana M.
AU  - Lazović, Vladimir
AU  - Trifunović, Snežana
AU  - Babić, Biljana M.
AU  - Dapčević, Aleksandra
AU  - Kovač, Janez
AU  - Vukčević, Marija M.
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5963
AB  - Abstract: N-doped TiO2/carbon composites (TiO2/CN) with different nitrogen content, were obtained starting from titanium isopropoxide and glucose, and by varying the amount of melamine, added to starting reaction mixture. For comparison, an undoped sample (TiO2/C) was also prepared. Structural and surface characteristics were determined through scanning electron microscopy, thermogravimetric analysis, elemental analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and nitrogen adsorption–desorption isotherms. The photocatalytic activity of TiO2/CN composites was examined via photocatalytic degradation of methylene blue and multiclass pharmaceuticals from water solution. It was found that N doping of TiO2/carbon composites induced changes in structural and surface characteristics of TiO2/CN composites, improving their adsorption, but decreasing photocatalytic efficiency. Nevertheless, TiO2/CN0.05 composite obtained by the hydrothermal synthesis in the presence of glucose and 0.05 g melamine showed the highest efficiency for removing selected pharmaceuticals and methylene blue from aqueous solutions through the combined processes of adsorption in the dark, and photocatalytic degradation under UV and visible irradiation.
T2  - Journal of the Serbian Chemical Society
T1  - Influence of N doping on structural and photocatalytic properties of hydrothermally synthesized TiO2/carbon composites
EP  - 197
IS  - 2
SP  - 183
VL  - 88
DO  - 10.2298/JSC220608079M
ER  - 

@article{
author = "Maletić, Marina M. and Kalijadis, Ana M. and Lazović, Vladimir and Trifunović, Snežana and Babić, Biljana M. and Dapčević, Aleksandra and Kovač, Janez and Vukčević, Marija M.",
year = "2023",
abstract = "Abstract: N-doped TiO2/carbon composites (TiO2/CN) with different nitrogen content, were obtained starting from titanium isopropoxide and glucose, and by varying the amount of melamine, added to starting reaction mixture. For comparison, an undoped sample (TiO2/C) was also prepared. Structural and surface characteristics were determined through scanning electron microscopy, thermogravimetric analysis, elemental analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and nitrogen adsorption–desorption isotherms. The photocatalytic activity of TiO2/CN composites was examined via photocatalytic degradation of methylene blue and multiclass pharmaceuticals from water solution. It was found that N doping of TiO2/carbon composites induced changes in structural and surface characteristics of TiO2/CN composites, improving their adsorption, but decreasing photocatalytic efficiency. Nevertheless, TiO2/CN0.05 composite obtained by the hydrothermal synthesis in the presence of glucose and 0.05 g melamine showed the highest efficiency for removing selected pharmaceuticals and methylene blue from aqueous solutions through the combined processes of adsorption in the dark, and photocatalytic degradation under UV and visible irradiation.",
journal = "Journal of the Serbian Chemical Society",
title = "Influence of N doping on structural and photocatalytic properties of hydrothermally synthesized TiO2/carbon composites",
pages = "197-183",
number = "2",
volume = "88",
doi = "10.2298/JSC220608079M"
}

Maletić, M. M., Kalijadis, A. M., Lazović, V., Trifunović, S., Babić, B. M., Dapčević, A., Kovač, J.,& Vukčević, M. M.. (2023). Influence of N doping on structural and photocatalytic properties of hydrothermally synthesized TiO2/carbon composites. in Journal of the Serbian Chemical Society, 88(2), 183-197.
https://doi.org/10.2298/JSC220608079M

Maletić MM, Kalijadis AM, Lazović V, Trifunović S, Babić BM, Dapčević A, Kovač J, Vukčević MM. Influence of N doping on structural and photocatalytic properties of hydrothermally synthesized TiO2/carbon composites. in Journal of the Serbian Chemical Society. 2023;88(2):183-197.
doi:10.2298/JSC220608079M .

Maletić, Marina M., Kalijadis, Ana M., Lazović, Vladimir, Trifunović, Snežana, Babić, Biljana M., Dapčević, Aleksandra, Kovač, Janez, Vukčević, Marija M., "Influence of N doping on structural and photocatalytic properties of hydrothermally synthesized TiO2/carbon composites" in Journal of the Serbian Chemical Society, 88, no. 2 (2023):183-197,
https://doi.org/10.2298/JSC220608079M . .

TY  - JOUR
AU  - Kalebić, Barbara
AU  - Škoro, Nikola
AU  - Kovač, Janez
AU  - Rajić, Nevenka
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5066
AB  - Natural clinoptilolite (CLI) exhibited a high efficacy in ciprofloxacin (CIP) removal from aqueous solution by adsorption. However, the regeneration of the spent adsorbent was a challenge since the adsorption occurred via electrostatic interactions and ion-exchange reaction. Herein, the feasibility of non-thermal plasma (NTP) was studied for the regeneration of ciprofloxacin-containing clinoptilolite (CIP-CLI) in five successive adsorption/NTP regeneration cycles. The NTP treatments were performed using a surface dielectric barrier discharge (SDBD) operating at atmospheric pressure in air. Plasma discharge gap, sample mass, and electrode surfaces were varied to find optimal regeneration parameters. For the plasma source with an electrode surface of 37.2 cm2, the 2 mm electrode gap and 20 min of plasma treatment were found as optimal parameters (sample mass of 0.2 g). The plasma treatment did not affect clinoptilolite features which were concluded from a study of textural properties and powder X-ray diffraction (PXRD) analysis. X-ray photoelectron spectroscopy (XPS) showed a decrease of total carbon content with around 10% of carbon residual left on the surface. The CLI adsorption capacity can be regenerated to at least 90% of its initial capacity during the five successive cycles, showing the involvement of plasma reactive species in decomposition of adsorbed CIP.
PB  - Elsevier
T2  - Applied Surface Science
T1  - Regeneration of the ciprofloxacin-loaded clinoptilolite by non-thermal atmospheric plasma
SP  - 153379
SP  - 153379
VL  - 593
DO  - doi.org/10.1016/j.apsusc.2022.153379
ER  - 

@article{
author = "Kalebić, Barbara and Škoro, Nikola and Kovač, Janez and Rajić, Nevenka",
year = "2022",
abstract = "Natural clinoptilolite (CLI) exhibited a high efficacy in ciprofloxacin (CIP) removal from aqueous solution by adsorption. However, the regeneration of the spent adsorbent was a challenge since the adsorption occurred via electrostatic interactions and ion-exchange reaction. Herein, the feasibility of non-thermal plasma (NTP) was studied for the regeneration of ciprofloxacin-containing clinoptilolite (CIP-CLI) in five successive adsorption/NTP regeneration cycles. The NTP treatments were performed using a surface dielectric barrier discharge (SDBD) operating at atmospheric pressure in air. Plasma discharge gap, sample mass, and electrode surfaces were varied to find optimal regeneration parameters. For the plasma source with an electrode surface of 37.2 cm2, the 2 mm electrode gap and 20 min of plasma treatment were found as optimal parameters (sample mass of 0.2 g). The plasma treatment did not affect clinoptilolite features which were concluded from a study of textural properties and powder X-ray diffraction (PXRD) analysis. X-ray photoelectron spectroscopy (XPS) showed a decrease of total carbon content with around 10% of carbon residual left on the surface. The CLI adsorption capacity can be regenerated to at least 90% of its initial capacity during the five successive cycles, showing the involvement of plasma reactive species in decomposition of adsorbed CIP.",
publisher = "Elsevier",
journal = "Applied Surface Science",
title = "Regeneration of the ciprofloxacin-loaded clinoptilolite by non-thermal atmospheric plasma",
pages = "153379-153379",
volume = "593",
doi = "doi.org/10.1016/j.apsusc.2022.153379"
}

Kalebić, B., Škoro, N., Kovač, J.,& Rajić, N.. (2022). Regeneration of the ciprofloxacin-loaded clinoptilolite by non-thermal atmospheric plasma. in Applied Surface Science
Elsevier., 593, 153379.
https://doi.org/doi.org/10.1016/j.apsusc.2022.153379

Kalebić B, Škoro N, Kovač J, Rajić N. Regeneration of the ciprofloxacin-loaded clinoptilolite by non-thermal atmospheric plasma. in Applied Surface Science. 2022;593:153379.
doi:doi.org/10.1016/j.apsusc.2022.153379 .

Kalebić, Barbara, Škoro, Nikola, Kovač, Janez, Rajić, Nevenka, "Regeneration of the ciprofloxacin-loaded clinoptilolite by non-thermal atmospheric plasma" in Applied Surface Science, 593 (2022):153379,
https://doi.org/doi.org/10.1016/j.apsusc.2022.153379 . .

TY  - JOUR
AU  - Pavlović, Jelena
AU  - Popova, M.
AU  - Mihalyi, R. M.
AU  - Mazaj, Matjaz
AU  - Mali, Gregor
AU  - Kovač, Janez
AU  - Lazarova, H.
AU  - Rajić, Nevenka
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4157
AB  - Catalysts based on natural zeolite - clinoptilolite loaded with either SnO2 (TOHCLI) or sulfated SnO2 (STOHCLI) were prepared and tested in the esterification of levulinic acid (LA) with octanol or ethanol. The Sn content in TOHCLI and STOHCLI varied from 4.5 to 12.3 wt.%. The catalysts were characterized by powder X-ray diffraction method, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, thermal analysis, X-ray photoelectron spectroscopy, NZ physisorption at - 196 degrees C, (27)A1 and Si-29 MAS NMR solid state spectroscopy and FTIR spectroscopy for analysis of acidic centers. A high conversion rate of LA into octyl- (OLA) or ethyl levulinate (ELA) was obtained for both TOHCLI and STOHCLI. TOHCLI showed a high activity in the conversion of LA into OLA (55%) and a moderate activity in the conversion to ELA (22%). STOHCLI led to a total conversion of LA to OLA and ELA due to the presence of a high amount of Bronsted and Lewis acid sites in the catalysts. The catalytic activity decreased to 86% for OLA and to 66% for ELA after next five cycles. Lower catalytic activity in the repeated cycles during ELA formation was explained by pore blockage due to coke formation.
PB  - Elsevier B.V.
T2  - Microporous and Mesoporous Materials
T1  - Catalytic activity of SnO2- and SO4 /SnO2-containing clinoptilolite in the esterification of levulinic acid
EP  - 18
SP  - 10
VL  - 279
DO  - 10.1016/j.micromeso.2018.12.009
ER  - 

@article{
author = "Pavlović, Jelena and Popova, M. and Mihalyi, R. M. and Mazaj, Matjaz and Mali, Gregor and Kovač, Janez and Lazarova, H. and Rajić, Nevenka",
year = "2019",
abstract = "Catalysts based on natural zeolite - clinoptilolite loaded with either SnO2 (TOHCLI) or sulfated SnO2 (STOHCLI) were prepared and tested in the esterification of levulinic acid (LA) with octanol or ethanol. The Sn content in TOHCLI and STOHCLI varied from 4.5 to 12.3 wt.%. The catalysts were characterized by powder X-ray diffraction method, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, thermal analysis, X-ray photoelectron spectroscopy, NZ physisorption at - 196 degrees C, (27)A1 and Si-29 MAS NMR solid state spectroscopy and FTIR spectroscopy for analysis of acidic centers. A high conversion rate of LA into octyl- (OLA) or ethyl levulinate (ELA) was obtained for both TOHCLI and STOHCLI. TOHCLI showed a high activity in the conversion of LA into OLA (55%) and a moderate activity in the conversion to ELA (22%). STOHCLI led to a total conversion of LA to OLA and ELA due to the presence of a high amount of Bronsted and Lewis acid sites in the catalysts. The catalytic activity decreased to 86% for OLA and to 66% for ELA after next five cycles. Lower catalytic activity in the repeated cycles during ELA formation was explained by pore blockage due to coke formation.",
publisher = "Elsevier B.V.",
journal = "Microporous and Mesoporous Materials",
title = "Catalytic activity of SnO2- and SO4 /SnO2-containing clinoptilolite in the esterification of levulinic acid",
pages = "18-10",
volume = "279",
doi = "10.1016/j.micromeso.2018.12.009"
}

Pavlović, J., Popova, M., Mihalyi, R. M., Mazaj, M., Mali, G., Kovač, J., Lazarova, H.,& Rajić, N.. (2019). Catalytic activity of SnO2- and SO4 /SnO2-containing clinoptilolite in the esterification of levulinic acid. in Microporous and Mesoporous Materials
Elsevier B.V.., 279, 10-18.
https://doi.org/10.1016/j.micromeso.2018.12.009

Pavlović J, Popova M, Mihalyi RM, Mazaj M, Mali G, Kovač J, Lazarova H, Rajić N. Catalytic activity of SnO2- and SO4 /SnO2-containing clinoptilolite in the esterification of levulinic acid. in Microporous and Mesoporous Materials. 2019;279:10-18.
doi:10.1016/j.micromeso.2018.12.009 .

Pavlović, Jelena, Popova, M., Mihalyi, R. M., Mazaj, Matjaz, Mali, Gregor, Kovač, Janez, Lazarova, H., Rajić, Nevenka, "Catalytic activity of SnO2- and SO4 /SnO2-containing clinoptilolite in the esterification of levulinic acid" in Microporous and Mesoporous Materials, 279 (2019):10-18,
https://doi.org/10.1016/j.micromeso.2018.12.009 . .

TY  - JOUR
AU  - Pavlović, Jelena
AU  - Popova, M.
AU  - Mihalyi, R. M.
AU  - Mazaj, Matjaz
AU  - Mali, Gregor
AU  - Kovač, Janez
AU  - Lazarova, H.
AU  - Rajić, Nevenka
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5042
AB  - Catalysts based on natural zeolite – clinoptilolite loaded with either SnO2 (TOHCLI) or sulfated SnO2 (STOHCLI) were prepared and tested in the esterification of levulinic acid (LA) with octanol or ethanol. The Sn content in TOHCLI and STOHCLI varied from 4.5 to 12.3 wt.%. The catalysts were characterized by powder X-ray diffraction method, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, thermal analysis, X-ray photoelectron spectroscopy, N2 physisorption at −196 °C, 27Al and 29Si MAS NMR solid state spectroscopy and FTIR spectroscopy for analysis of acidic centers. A high conversion rate of LA into octyl- (OLA) or ethyl levulinate (ELA) was obtained for both TOHCLI and STOHCLI. TOHCLI showed a high activity in the conversion of LA into OLA (55%) and a moderate activity in the conversion to ELA (22%). STOHCLI led to a total conversion of LA to OLA and ELA due to the presence of a high amount of Brønsted and Lewis acid sites in the catalysts. The catalytic activity decreased to 86% for OLA and to 66% for ELA after next five cycles. Lower catalytic activity in the repeated cycles during ELA formation was explained by pore blockage due to coke formation.
PB  - Elsevier B.V.
T2  - Microporous and Mesoporous Materials
T1  - Catalytic activity of SnO2- and SO4/SnO2-containing clinoptilolite in the esterification of levulinic acid
EP  - 18
SP  - 10
VL  - 279
DO  - 10.1016/j.micromeso.2018.12.009
ER  - 

@article{
author = "Pavlović, Jelena and Popova, M. and Mihalyi, R. M. and Mazaj, Matjaz and Mali, Gregor and Kovač, Janez and Lazarova, H. and Rajić, Nevenka",
year = "2019",
abstract = "Catalysts based on natural zeolite – clinoptilolite loaded with either SnO2 (TOHCLI) or sulfated SnO2 (STOHCLI) were prepared and tested in the esterification of levulinic acid (LA) with octanol or ethanol. The Sn content in TOHCLI and STOHCLI varied from 4.5 to 12.3 wt.%. The catalysts were characterized by powder X-ray diffraction method, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, thermal analysis, X-ray photoelectron spectroscopy, N2 physisorption at −196 °C, 27Al and 29Si MAS NMR solid state spectroscopy and FTIR spectroscopy for analysis of acidic centers. A high conversion rate of LA into octyl- (OLA) or ethyl levulinate (ELA) was obtained for both TOHCLI and STOHCLI. TOHCLI showed a high activity in the conversion of LA into OLA (55%) and a moderate activity in the conversion to ELA (22%). STOHCLI led to a total conversion of LA to OLA and ELA due to the presence of a high amount of Brønsted and Lewis acid sites in the catalysts. The catalytic activity decreased to 86% for OLA and to 66% for ELA after next five cycles. Lower catalytic activity in the repeated cycles during ELA formation was explained by pore blockage due to coke formation.",
publisher = "Elsevier B.V.",
journal = "Microporous and Mesoporous Materials",
title = "Catalytic activity of SnO2- and SO4/SnO2-containing clinoptilolite in the esterification of levulinic acid",
pages = "18-10",
volume = "279",
doi = "10.1016/j.micromeso.2018.12.009"
}

Pavlović, J., Popova, M., Mihalyi, R. M., Mazaj, M., Mali, G., Kovač, J., Lazarova, H.,& Rajić, N.. (2019). Catalytic activity of SnO2- and SO4/SnO2-containing clinoptilolite in the esterification of levulinic acid. in Microporous and Mesoporous Materials
Elsevier B.V.., 279, 10-18.
https://doi.org/10.1016/j.micromeso.2018.12.009

Pavlović J, Popova M, Mihalyi RM, Mazaj M, Mali G, Kovač J, Lazarova H, Rajić N. Catalytic activity of SnO2- and SO4/SnO2-containing clinoptilolite in the esterification of levulinic acid. in Microporous and Mesoporous Materials. 2019;279:10-18.
doi:10.1016/j.micromeso.2018.12.009 .

Pavlović, Jelena, Popova, M., Mihalyi, R. M., Mazaj, Matjaz, Mali, Gregor, Kovač, Janez, Lazarova, H., Rajić, Nevenka, "Catalytic activity of SnO2- and SO4/SnO2-containing clinoptilolite in the esterification of levulinic acid" in Microporous and Mesoporous Materials, 279 (2019):10-18,
https://doi.org/10.1016/j.micromeso.2018.12.009 . .

TY  - JOUR
AU  - Habish, Amal Juma
AU  - Lazarević, Slavica
AU  - Janković-Častvan, Ivona
AU  - Jokić, Bojan
AU  - Kovač, Janez
AU  - Rogan, Jelena
AU  - Janaćković, Đorđe
AU  - Petrović, Rada
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3676
AB  - Natural (SEP) and partially acid-activated (AAS) sepiolites were used to prepare composites with nanoscale zerovalent iron (nZVI) at different (SEP or AAS)/nZVI ratios in order to achieve the best nZVI dispersibility and the highest adsorption capacity for Cd2+. Despite the higher surface area and pore volume of AAS, better nZVI dispersibility was achieved by using SEP as the support. On the other hand, a lower oxidation degree was achieved during the synthesis using AAS. X-ray photoelectron spectroscopy (XPS) analysis of the composite with the best nZVI dispersibility, before and after Cd2+ adsorption, confirmed that the surface of the nZVI was composed of oxidized iron species. Metallic iron was not present on the surface, but it was detected in the subsurface region after sputtering. The content of zerovalent iron decreased after Cd2+ adsorption as a result of iron oxidation during Cd2+ adsorption. The XPS depth profile showed that cadmium was present not only at the surface of the composite but also in the subsurface region. The adsorption isotherms for Cd2+ confirmed that the presence of SEP and AAS decreased the agglomeration of the nZVI particles in comparison to the pure nZVI, which provided a higher adsorption capacity. The results showed that the prevention of both aggregation and oxidation during the synthesis was necessary for obtaining an SEP/AAS-nZVI composite with a high adsorption capacity, but oxidation during adsorption was beneficial for Cd2+ removal. The formation of strong bonds between Cd2+ and the adsorbents sites of different energy until monolayer formation was proposed according to modeling of the adsorption isotherms.
PB  - Springer Heidelberg, Heidelberg
T2  - Environmental Science and Pollution Research
T1  - Nanoscale zerovalent iron (nZVI) supported by natural and acid-activated sepiolites: the effect of the nZVI/support ratio on the composite properties and Cd2+ adsorption
EP  - 643
IS  - 1
SP  - 628
VL  - 24
DO  - 10.1007/s11356-016-7802-y
ER  - 

@article{
author = "Habish, Amal Juma and Lazarević, Slavica and Janković-Častvan, Ivona and Jokić, Bojan and Kovač, Janez and Rogan, Jelena and Janaćković, Đorđe and Petrović, Rada",
year = "2017",
abstract = "Natural (SEP) and partially acid-activated (AAS) sepiolites were used to prepare composites with nanoscale zerovalent iron (nZVI) at different (SEP or AAS)/nZVI ratios in order to achieve the best nZVI dispersibility and the highest adsorption capacity for Cd2+. Despite the higher surface area and pore volume of AAS, better nZVI dispersibility was achieved by using SEP as the support. On the other hand, a lower oxidation degree was achieved during the synthesis using AAS. X-ray photoelectron spectroscopy (XPS) analysis of the composite with the best nZVI dispersibility, before and after Cd2+ adsorption, confirmed that the surface of the nZVI was composed of oxidized iron species. Metallic iron was not present on the surface, but it was detected in the subsurface region after sputtering. The content of zerovalent iron decreased after Cd2+ adsorption as a result of iron oxidation during Cd2+ adsorption. The XPS depth profile showed that cadmium was present not only at the surface of the composite but also in the subsurface region. The adsorption isotherms for Cd2+ confirmed that the presence of SEP and AAS decreased the agglomeration of the nZVI particles in comparison to the pure nZVI, which provided a higher adsorption capacity. The results showed that the prevention of both aggregation and oxidation during the synthesis was necessary for obtaining an SEP/AAS-nZVI composite with a high adsorption capacity, but oxidation during adsorption was beneficial for Cd2+ removal. The formation of strong bonds between Cd2+ and the adsorbents sites of different energy until monolayer formation was proposed according to modeling of the adsorption isotherms.",
publisher = "Springer Heidelberg, Heidelberg",
journal = "Environmental Science and Pollution Research",
title = "Nanoscale zerovalent iron (nZVI) supported by natural and acid-activated sepiolites: the effect of the nZVI/support ratio on the composite properties and Cd2+ adsorption",
pages = "643-628",
number = "1",
volume = "24",
doi = "10.1007/s11356-016-7802-y"
}

Habish, A. J., Lazarević, S., Janković-Častvan, I., Jokić, B., Kovač, J., Rogan, J., Janaćković, Đ.,& Petrović, R.. (2017). Nanoscale zerovalent iron (nZVI) supported by natural and acid-activated sepiolites: the effect of the nZVI/support ratio on the composite properties and Cd2+ adsorption. in Environmental Science and Pollution Research
Springer Heidelberg, Heidelberg., 24(1), 628-643.
https://doi.org/10.1007/s11356-016-7802-y

Habish AJ, Lazarević S, Janković-Častvan I, Jokić B, Kovač J, Rogan J, Janaćković Đ, Petrović R. Nanoscale zerovalent iron (nZVI) supported by natural and acid-activated sepiolites: the effect of the nZVI/support ratio on the composite properties and Cd2+ adsorption. in Environmental Science and Pollution Research. 2017;24(1):628-643.
doi:10.1007/s11356-016-7802-y .

Habish, Amal Juma, Lazarević, Slavica, Janković-Častvan, Ivona, Jokić, Bojan, Kovač, Janez, Rogan, Jelena, Janaćković, Đorđe, Petrović, Rada, "Nanoscale zerovalent iron (nZVI) supported by natural and acid-activated sepiolites: the effect of the nZVI/support ratio on the composite properties and Cd2+ adsorption" in Environmental Science and Pollution Research, 24, no. 1 (2017):628-643,
https://doi.org/10.1007/s11356-016-7802-y . .

TY  - JOUR
AU  - Jović, Borka
AU  - Lačnjevac, Uroš
AU  - Jović, Vladimir
AU  - Gajić Krstajić, Ljiljana
AU  - Kovač, Janez
AU  - Poleti, Dejan
AU  - Krstajić, Nedeljko
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5833
AB  - The oxygen evolution reaction (OER) was studied at pure Ni and Ni-(Ebonex/Ir) composite coatings in 1 M NaOH solution at 25 °C. Ni-(Ebonex-supported Ir) coatings were electrodeposited from a nickel Watts bath containing different concentrations of suspended Ebonex/Ir particles (0–2 g dm−3) onto a Ni 40 mesh substrate. The surface morphology of the coatings was examined by scanning electron microscopy (SEM), the surface composition by energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRPD) and X-ray photoelectron spectroscopy (XPS), whereas the electrochemical properties were studied by electrochemical impedance spectroscopy (EIS), polarization measurements and cyclic voltammetry (CV). It was shown that the roughness factor of Ni-(Ebonex/Ir) composite coatings calculated relative to the surface area of the pure Ni sample increased with the increasing content of Ebonex/Ir particles in the bath to a maximum value of 40.6. All samples displayed a Tafel slope of about 60 mV dec−1 in the potential range corresponding to lower current densities for the OER. The increase of the apparent activity for the OER at Ni-(Ebonex/Ir) coatings compared with the pure Ni coating was attributed only to the increase of the electrochemically active surface area. Although the pure Ni coating initially exhibited higher intrinsic catalytic activity for the OER than the composite coatings, it also showed a drastic loss of activity after subjecting to continuous oxygen evolution at j = 50 mA cm−2 for 24 h (ΔE = 395 mV). At the same time, the OER overpotential at Ni-(Ebonex/Ir) coatings only negligibly increased after the stability test (ΔE = 22 mV). The improved retention of catalytic activity observed with Ni-(Ebonex/Ir) coatings was ascribed to the presence of IrO2, which inhibited the formation of the inactive γ-NiOOH phase.
PB  - Elsevier Ltd.
T2  - International Journal of Hydrogen Energy
T1  - Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution
EP  - 20514
IS  - 45
SP  - 20502
VL  - 41
DO  - 10.1016/j.ijhydene.2016.08.226
UR  - https://hdl.handle.net/21.15107/rcub_dais_15978
ER  - 

@article{
author = "Jović, Borka and Lačnjevac, Uroš and Jović, Vladimir and Gajić Krstajić, Ljiljana and Kovač, Janez and Poleti, Dejan and Krstajić, Nedeljko",
year = "2016",
abstract = "The oxygen evolution reaction (OER) was studied at pure Ni and Ni-(Ebonex/Ir) composite coatings in 1 M NaOH solution at 25 °C. Ni-(Ebonex-supported Ir) coatings were electrodeposited from a nickel Watts bath containing different concentrations of suspended Ebonex/Ir particles (0–2 g dm−3) onto a Ni 40 mesh substrate. The surface morphology of the coatings was examined by scanning electron microscopy (SEM), the surface composition by energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRPD) and X-ray photoelectron spectroscopy (XPS), whereas the electrochemical properties were studied by electrochemical impedance spectroscopy (EIS), polarization measurements and cyclic voltammetry (CV). It was shown that the roughness factor of Ni-(Ebonex/Ir) composite coatings calculated relative to the surface area of the pure Ni sample increased with the increasing content of Ebonex/Ir particles in the bath to a maximum value of 40.6. All samples displayed a Tafel slope of about 60 mV dec−1 in the potential range corresponding to lower current densities for the OER. The increase of the apparent activity for the OER at Ni-(Ebonex/Ir) coatings compared with the pure Ni coating was attributed only to the increase of the electrochemically active surface area. Although the pure Ni coating initially exhibited higher intrinsic catalytic activity for the OER than the composite coatings, it also showed a drastic loss of activity after subjecting to continuous oxygen evolution at j = 50 mA cm−2 for 24 h (ΔE = 395 mV). At the same time, the OER overpotential at Ni-(Ebonex/Ir) coatings only negligibly increased after the stability test (ΔE = 22 mV). The improved retention of catalytic activity observed with Ni-(Ebonex/Ir) coatings was ascribed to the presence of IrO2, which inhibited the formation of the inactive γ-NiOOH phase.",
publisher = "Elsevier Ltd.",
journal = "International Journal of Hydrogen Energy",
title = "Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution",
pages = "20514-20502",
number = "45",
volume = "41",
doi = "10.1016/j.ijhydene.2016.08.226",
url = "https://hdl.handle.net/21.15107/rcub_dais_15978"
}

Jović, B., Lačnjevac, U., Jović, V., Gajić Krstajić, L., Kovač, J., Poleti, D.,& Krstajić, N.. (2016). Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution. in International Journal of Hydrogen Energy
Elsevier Ltd.., 41(45), 20502-20514.
https://doi.org/10.1016/j.ijhydene.2016.08.226
https://hdl.handle.net/21.15107/rcub_dais_15978

Jović B, Lačnjevac U, Jović V, Gajić Krstajić L, Kovač J, Poleti D, Krstajić N. Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution. in International Journal of Hydrogen Energy. 2016;41(45):20502-20514.
doi:10.1016/j.ijhydene.2016.08.226
https://hdl.handle.net/21.15107/rcub_dais_15978 .

Jović, Borka, Lačnjevac, Uroš, Jović, Vladimir, Gajić Krstajić, Ljiljana, Kovač, Janez, Poleti, Dejan, Krstajić, Nedeljko, "Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution" in International Journal of Hydrogen Energy, 41, no. 45 (2016):20502-20514,
https://doi.org/10.1016/j.ijhydene.2016.08.226 .,
https://hdl.handle.net/21.15107/rcub_dais_15978 .

TY  - JOUR
AU  - Jovanović, Mina
AU  - Arcon, Iztok
AU  - Kovač, Janez
AU  - Novak-Tusar, Nataša
AU  - Obradović, Bojana
AU  - Rajić, Nevenka
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3440
AB  - In this study the uptake capacity of Mn(II) ions by zeolite A beads was investigated for different initial Mn concentration (100-400 mg Mn dm(-3)) in batch mode at 25-55 degrees C. The obtained adsorption capacity varying from 30 to 50 mg Mn g(-1) demonstrated a high affinity of zeolite A towards Mn(II) present in solutions. Kinetic studies indicated the intra-particle diffusion as the rate limiting step up to 45 degrees C with apparent diffusivities in the range (1.2-2.0) x 10(-13) m(2) s(-1) and the activation energy of 21.9 kJ mol(-1), which implies strong interactions between the zeolite A and Mn ions. At 55 degrees C ion-exchange became the rate limiting step. The adsorption isotherms were studied at 25 degrees C showing that the Mn adsorption is the best described by the Langmuir model suggesting a homogenous zeolite surface. XPS analysis of the Mn-loaded beads showed that there is no surface accumulation of Mn but an almost uniform Mn distribution inside zeolite A, whereas XANES and EXAFS suggested that the adsorption of Mn(II) was followed by the Mn(II) oxidation and oxide formation. Regeneration of the spent zeolite was examined in 8 adsorption/desorption cycles by a chelating Na(2)EDTA in a fluidized column. It has been found that zeolite A beads could be reused for at least 4 cycles with satisfactory Mn(II) adsorption efficiencies of about 70%.
PB  - Elsevier Science Bv, Amsterdam
T2  - Microporous and Mesoporous Materials
T1  - Removal of manganese in batch and fluidized bed systems using beads of zeolite a as adsorbent
EP  - 385
SP  - 378
VL  - 226
DO  - 10.1016/j.micromeso.2016.02.026
ER  - 

@article{
author = "Jovanović, Mina and Arcon, Iztok and Kovač, Janez and Novak-Tusar, Nataša and Obradović, Bojana and Rajić, Nevenka",
year = "2016",
abstract = "In this study the uptake capacity of Mn(II) ions by zeolite A beads was investigated for different initial Mn concentration (100-400 mg Mn dm(-3)) in batch mode at 25-55 degrees C. The obtained adsorption capacity varying from 30 to 50 mg Mn g(-1) demonstrated a high affinity of zeolite A towards Mn(II) present in solutions. Kinetic studies indicated the intra-particle diffusion as the rate limiting step up to 45 degrees C with apparent diffusivities in the range (1.2-2.0) x 10(-13) m(2) s(-1) and the activation energy of 21.9 kJ mol(-1), which implies strong interactions between the zeolite A and Mn ions. At 55 degrees C ion-exchange became the rate limiting step. The adsorption isotherms were studied at 25 degrees C showing that the Mn adsorption is the best described by the Langmuir model suggesting a homogenous zeolite surface. XPS analysis of the Mn-loaded beads showed that there is no surface accumulation of Mn but an almost uniform Mn distribution inside zeolite A, whereas XANES and EXAFS suggested that the adsorption of Mn(II) was followed by the Mn(II) oxidation and oxide formation. Regeneration of the spent zeolite was examined in 8 adsorption/desorption cycles by a chelating Na(2)EDTA in a fluidized column. It has been found that zeolite A beads could be reused for at least 4 cycles with satisfactory Mn(II) adsorption efficiencies of about 70%.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Microporous and Mesoporous Materials",
title = "Removal of manganese in batch and fluidized bed systems using beads of zeolite a as adsorbent",
pages = "385-378",
volume = "226",
doi = "10.1016/j.micromeso.2016.02.026"
}

Jovanović, M., Arcon, I., Kovač, J., Novak-Tusar, N., Obradović, B.,& Rajić, N.. (2016). Removal of manganese in batch and fluidized bed systems using beads of zeolite a as adsorbent. in Microporous and Mesoporous Materials
Elsevier Science Bv, Amsterdam., 226, 378-385.
https://doi.org/10.1016/j.micromeso.2016.02.026

Jovanović M, Arcon I, Kovač J, Novak-Tusar N, Obradović B, Rajić N. Removal of manganese in batch and fluidized bed systems using beads of zeolite a as adsorbent. in Microporous and Mesoporous Materials. 2016;226:378-385.
doi:10.1016/j.micromeso.2016.02.026 .

Jovanović, Mina, Arcon, Iztok, Kovač, Janez, Novak-Tusar, Nataša, Obradović, Bojana, Rajić, Nevenka, "Removal of manganese in batch and fluidized bed systems using beads of zeolite a as adsorbent" in Microporous and Mesoporous Materials, 226 (2016):378-385,
https://doi.org/10.1016/j.micromeso.2016.02.026 . .

TY  - JOUR
AU  - Albrbar, Asma Juma
AU  - Đokić, Veljko
AU  - Bjelajac, Anđelika
AU  - Kovač, Janez
AU  - Ćirković, Jovana
AU  - Mitrić, Miodrag
AU  - Janaćković, Đorđe
AU  - Petrović, Rada
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3330
AB  - Visible-light active mesoporous N,S-doped and co-doped anatase TiO2 powders were synthesized by non-hydrolytic sol-gel route, starting from TiCl4 and Ti((OPr)-Pr-i)(4) dissolved in cyclohexane or dimethyl sulfoxide, later used as a S-doping agent. After drying in an inert atmosphere, the gels were annealed at 500 degrees C for 3 h, in air or ammonia flow, later used for N-doping. The undoped titania powder, obtained by annealing in air of the cyclohexane-based gel, was also annealed in ammonia to deduce which method is more efficient for N-doping: gel or powder annealing. The post-annealing in air after annealing in ammonia was optimized to attain the best photocatalytic activity for dye degradation under simulated visible light. The size of anatase nanocrystals decreased by doping and the specific surface area of the powders increased. The XPS analysis confirmed a successful substitution of Ti4+ by S(4+) and/or S(6+), which caused a very small band-gap narrowing. The gel annealing in ammonia was much more efficient for interstitial nitrogen incorporation in TiO2 lattice than the powder annealing. The annealing in ammonia of the gel synthesized with dimethyl sulfoxide provided the highest visible-light activity owing to high specific surface area, appropriate mesoporosity and high photoabsorption due to efficient N,S co-doping.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route
EP  - 16728
IS  - 15
SP  - 16718
VL  - 42
DO  - 10.1016/j.ceramint.2016.07.144
ER  - 

@article{
author = "Albrbar, Asma Juma and Đokić, Veljko and Bjelajac, Anđelika and Kovač, Janez and Ćirković, Jovana and Mitrić, Miodrag and Janaćković, Đorđe and Petrović, Rada",
year = "2016",
abstract = "Visible-light active mesoporous N,S-doped and co-doped anatase TiO2 powders were synthesized by non-hydrolytic sol-gel route, starting from TiCl4 and Ti((OPr)-Pr-i)(4) dissolved in cyclohexane or dimethyl sulfoxide, later used as a S-doping agent. After drying in an inert atmosphere, the gels were annealed at 500 degrees C for 3 h, in air or ammonia flow, later used for N-doping. The undoped titania powder, obtained by annealing in air of the cyclohexane-based gel, was also annealed in ammonia to deduce which method is more efficient for N-doping: gel or powder annealing. The post-annealing in air after annealing in ammonia was optimized to attain the best photocatalytic activity for dye degradation under simulated visible light. The size of anatase nanocrystals decreased by doping and the specific surface area of the powders increased. The XPS analysis confirmed a successful substitution of Ti4+ by S(4+) and/or S(6+), which caused a very small band-gap narrowing. The gel annealing in ammonia was much more efficient for interstitial nitrogen incorporation in TiO2 lattice than the powder annealing. The annealing in ammonia of the gel synthesized with dimethyl sulfoxide provided the highest visible-light activity owing to high specific surface area, appropriate mesoporosity and high photoabsorption due to efficient N,S co-doping.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route",
pages = "16728-16718",
number = "15",
volume = "42",
doi = "10.1016/j.ceramint.2016.07.144"
}

Albrbar, A. J., Đokić, V., Bjelajac, A., Kovač, J., Ćirković, J., Mitrić, M., Janaćković, Đ.,& Petrović, R.. (2016). Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route. in Ceramics International
Elsevier Sci Ltd, Oxford., 42(15), 16718-16728.
https://doi.org/10.1016/j.ceramint.2016.07.144

Albrbar AJ, Đokić V, Bjelajac A, Kovač J, Ćirković J, Mitrić M, Janaćković Đ, Petrović R. Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route. in Ceramics International. 2016;42(15):16718-16728.
doi:10.1016/j.ceramint.2016.07.144 .

Albrbar, Asma Juma, Đokić, Veljko, Bjelajac, Anđelika, Kovač, Janez, Ćirković, Jovana, Mitrić, Miodrag, Janaćković, Đorđe, Petrović, Rada, "Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route" in Ceramics International, 42, no. 15 (2016):16718-16728,
https://doi.org/10.1016/j.ceramint.2016.07.144 . .

TY  - JOUR
AU  - Mihajlović, Marija T.
AU  - Lazarević, Slavica
AU  - Janković-Častvan, Ivona
AU  - Kovač, Janez
AU  - Jokić, Bojan
AU  - Janaćković, Đorđe
AU  - Petrović, Rada
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3035
AB  - The adsorption of Pb2+, Cd2+, and Zn2+ from equimolar multicomponent solutions onto natural and Fe(III)-modified zeolites was studied by batch experiments in order to determine the influence of the competitive effect on the efficiency ions removal at different initial concentrations and different temperatures. Kinetic and equilibrium studies showed that affinity of both zeolites was the highest for Pb2+ and much lower for Zn2+ and Cd2+. The competitive effect was negligible at lower concentrations, while Zn2+ and especially Cd2+ ions adsorption was suppressed as the concentrations were increased. Affinity of natural zeolite toward the ions was lower than that of the modified zeolite, as was shown for adsorption from single-component solutions. External film diffusion was the rate-controlling step at lower concentrations and for ions of higher affinity for the adsorbent, while intraparticle diffusion was dominant at higher concentrations and for ions of lower affinity for the adsorbent. The increasing spontaneity of the adsorption process with increasing temperature and the positive values of enthalpy of adsorption indicated the endothermic nature of the adsorption process. Structural investigations of the adsorbents loaded with Pb2+, Cd2+, and Zn2+ ions by X-ray photoelectron spectroscopy (XPS) confirmed the higher content of the ions in the surface and subsurface regions of the Fe(III)-modified than of the natural zeolite. XPS depth profiles of the loaded Fe(III)-modified zeolite showed that surface mechanisms of adsorption were dominant in the case of lead and cadmium, while zinc loading on the zeolite sample was governed mainly by an ion-exchange process.
PB  - Springer, New York
T2  - Clean Technologies and Environmental Policy
T1  - Kinetics, thermodynamics, and structural investigations on the removal of Pb2+, Cd2+, and Zn2+ from multicomponent solutions onto natural and Fe(III)-modified zeolites
EP  - 419
IS  - 2
SP  - 407
VL  - 17
DO  - 10.1007/s10098-014-0794-8
ER  - 

@article{
author = "Mihajlović, Marija T. and Lazarević, Slavica and Janković-Častvan, Ivona and Kovač, Janez and Jokić, Bojan and Janaćković, Đorđe and Petrović, Rada",
year = "2015",
abstract = "The adsorption of Pb2+, Cd2+, and Zn2+ from equimolar multicomponent solutions onto natural and Fe(III)-modified zeolites was studied by batch experiments in order to determine the influence of the competitive effect on the efficiency ions removal at different initial concentrations and different temperatures. Kinetic and equilibrium studies showed that affinity of both zeolites was the highest for Pb2+ and much lower for Zn2+ and Cd2+. The competitive effect was negligible at lower concentrations, while Zn2+ and especially Cd2+ ions adsorption was suppressed as the concentrations were increased. Affinity of natural zeolite toward the ions was lower than that of the modified zeolite, as was shown for adsorption from single-component solutions. External film diffusion was the rate-controlling step at lower concentrations and for ions of higher affinity for the adsorbent, while intraparticle diffusion was dominant at higher concentrations and for ions of lower affinity for the adsorbent. The increasing spontaneity of the adsorption process with increasing temperature and the positive values of enthalpy of adsorption indicated the endothermic nature of the adsorption process. Structural investigations of the adsorbents loaded with Pb2+, Cd2+, and Zn2+ ions by X-ray photoelectron spectroscopy (XPS) confirmed the higher content of the ions in the surface and subsurface regions of the Fe(III)-modified than of the natural zeolite. XPS depth profiles of the loaded Fe(III)-modified zeolite showed that surface mechanisms of adsorption were dominant in the case of lead and cadmium, while zinc loading on the zeolite sample was governed mainly by an ion-exchange process.",
publisher = "Springer, New York",
journal = "Clean Technologies and Environmental Policy",
title = "Kinetics, thermodynamics, and structural investigations on the removal of Pb2+, Cd2+, and Zn2+ from multicomponent solutions onto natural and Fe(III)-modified zeolites",
pages = "419-407",
number = "2",
volume = "17",
doi = "10.1007/s10098-014-0794-8"
}

Mihajlović, M. T., Lazarević, S., Janković-Častvan, I., Kovač, J., Jokić, B., Janaćković, Đ.,& Petrović, R.. (2015). Kinetics, thermodynamics, and structural investigations on the removal of Pb2+, Cd2+, and Zn2+ from multicomponent solutions onto natural and Fe(III)-modified zeolites. in Clean Technologies and Environmental Policy
Springer, New York., 17(2), 407-419.
https://doi.org/10.1007/s10098-014-0794-8

Mihajlović MT, Lazarević S, Janković-Častvan I, Kovač J, Jokić B, Janaćković Đ, Petrović R. Kinetics, thermodynamics, and structural investigations on the removal of Pb2+, Cd2+, and Zn2+ from multicomponent solutions onto natural and Fe(III)-modified zeolites. in Clean Technologies and Environmental Policy. 2015;17(2):407-419.
doi:10.1007/s10098-014-0794-8 .

Mihajlović, Marija T., Lazarević, Slavica, Janković-Častvan, Ivona, Kovač, Janez, Jokić, Bojan, Janaćković, Đorđe, Petrović, Rada, "Kinetics, thermodynamics, and structural investigations on the removal of Pb2+, Cd2+, and Zn2+ from multicomponent solutions onto natural and Fe(III)-modified zeolites" in Clean Technologies and Environmental Policy, 17, no. 2 (2015):407-419,
https://doi.org/10.1007/s10098-014-0794-8 . .

TY  - JOUR
AU  - Elezović, Nevenka
AU  - Radmilović, Velimir R.
AU  - Kovač, Janez
AU  - Babić, Biljana M.
AU  - Gajić Krstajić, Ljiljana
AU  - Krstajić, Nedeljko
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5795
AB  - A platinum nanocatalyst on Sb doped tin oxide support (Sb-SnO2) was synthesized and characterized as a catalyst for oxygen reduction reaction in 0.1 mol dm(-3) NaOH solution at 25 degrees C. Sb (5%) doped tin oxide support was synthesized by a modified hydrazine reduction procedure. The platinum nanocatalyst (20% Pt) on Sb-SnO2 support was synthesized by a borohydride reduction method. The synthesized support and catalyst were characterized by high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS) and X-ray diffraction technique (XRD). X-ray photoelectron spectroscopy was applied to characterize the chemical status of elements before and after Pt-treatment. XPS spectra of Sn 3d, Pt 4f, Sb 3d and O 1s revealed that the Pt-deposition on Sb-SnO2 support induced the reduction of the Sn(4+) oxidation state to Sn(2+) and Sn(0) states, while Pt remained in the metallic state and Sb was in the (3+) oxidation state. Homogenous Pt nanoparticle distribution over the support, without pronounced particle agglomeration, was confirmed by HRTEM technique. The average Pt particle size was 2.9 nm. The electrochemically active Pt surface area of the catalyst was determined by the integration of the cyclic voltammetry curve in the potential region of underpotential deposition of hydrogen, after double layer charge correction, taking into account the reference value of 210 mu C cm(-2) for full monolayer coverage. This calculation gave the value of 51 m(2) g(-1). The kinetics of the oxygen reduction reaction with Pt/[Sb-SnO2 catalyst was studied by cyclic voltammetry and linear sweep voltammetry using a rotating gold disc electrode. Two different Tafel slopes were observed: one close to 60 mV dec(-1) in the low current density region, and another at similar to 120 mV dec(-1) in the higher current densities region, as was already referred in previous reports for the oxygen reduction reaction with polycrystalline Pt, as well as with different Pt based nanocatalysts. The specific activities for oxygen reduction, expressed in terms of kinetic current densities per electrochemically Pt active surface area, as well as per mass of Pt loaded, at the constant potential of practical interest (0.85 V and 0.90 V vs. RHE), were compared to a carbon supported (Vulcan XC-72) catalyst. The Pt/[Sb-SnO2 catalyst exhibited similar catalytic activity for oxygen reduction reaction like carbon supported one. The advantages of the carbon free support application in terms of the durability and stability of the catalysts were proved by accelerated stability tests.
PB  - Royal Society of Chemistry
T2  - RSC Advances
T1  - Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions
EP  - 15929
IS  - 21
SP  - 15923
VL  - 5
DO  - 10.1039/c4ra13391a
UR  - https://hdl.handle.net/21.15107/rcub_dais_3354
ER  - 

@article{
author = "Elezović, Nevenka and Radmilović, Velimir R. and Kovač, Janez and Babić, Biljana M. and Gajić Krstajić, Ljiljana and Krstajić, Nedeljko",
year = "2015",
abstract = "A platinum nanocatalyst on Sb doped tin oxide support (Sb-SnO2) was synthesized and characterized as a catalyst for oxygen reduction reaction in 0.1 mol dm(-3) NaOH solution at 25 degrees C. Sb (5%) doped tin oxide support was synthesized by a modified hydrazine reduction procedure. The platinum nanocatalyst (20% Pt) on Sb-SnO2 support was synthesized by a borohydride reduction method. The synthesized support and catalyst were characterized by high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS) and X-ray diffraction technique (XRD). X-ray photoelectron spectroscopy was applied to characterize the chemical status of elements before and after Pt-treatment. XPS spectra of Sn 3d, Pt 4f, Sb 3d and O 1s revealed that the Pt-deposition on Sb-SnO2 support induced the reduction of the Sn(4+) oxidation state to Sn(2+) and Sn(0) states, while Pt remained in the metallic state and Sb was in the (3+) oxidation state. Homogenous Pt nanoparticle distribution over the support, without pronounced particle agglomeration, was confirmed by HRTEM technique. The average Pt particle size was 2.9 nm. The electrochemically active Pt surface area of the catalyst was determined by the integration of the cyclic voltammetry curve in the potential region of underpotential deposition of hydrogen, after double layer charge correction, taking into account the reference value of 210 mu C cm(-2) for full monolayer coverage. This calculation gave the value of 51 m(2) g(-1). The kinetics of the oxygen reduction reaction with Pt/[Sb-SnO2 catalyst was studied by cyclic voltammetry and linear sweep voltammetry using a rotating gold disc electrode. Two different Tafel slopes were observed: one close to 60 mV dec(-1) in the low current density region, and another at similar to 120 mV dec(-1) in the higher current densities region, as was already referred in previous reports for the oxygen reduction reaction with polycrystalline Pt, as well as with different Pt based nanocatalysts. The specific activities for oxygen reduction, expressed in terms of kinetic current densities per electrochemically Pt active surface area, as well as per mass of Pt loaded, at the constant potential of practical interest (0.85 V and 0.90 V vs. RHE), were compared to a carbon supported (Vulcan XC-72) catalyst. The Pt/[Sb-SnO2 catalyst exhibited similar catalytic activity for oxygen reduction reaction like carbon supported one. The advantages of the carbon free support application in terms of the durability and stability of the catalysts were proved by accelerated stability tests.",
publisher = "Royal Society of Chemistry",
journal = "RSC Advances",
title = "Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions",
pages = "15929-15923",
number = "21",
volume = "5",
doi = "10.1039/c4ra13391a",
url = "https://hdl.handle.net/21.15107/rcub_dais_3354"
}

Elezović, N., Radmilović, V. R., Kovač, J., Babić, B. M., Gajić Krstajić, L.,& Krstajić, N.. (2015). Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions. in RSC Advances
Royal Society of Chemistry., 5(21), 15923-15929.
https://doi.org/10.1039/c4ra13391a
https://hdl.handle.net/21.15107/rcub_dais_3354

Elezović N, Radmilović VR, Kovač J, Babić BM, Gajić Krstajić L, Krstajić N. Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions. in RSC Advances. 2015;5(21):15923-15929.
doi:10.1039/c4ra13391a
https://hdl.handle.net/21.15107/rcub_dais_3354 .

Elezović, Nevenka, Radmilović, Velimir R., Kovač, Janez, Babić, Biljana M., Gajić Krstajić, Ljiljana, Krstajić, Nedeljko, "Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions" in RSC Advances, 5, no. 21 (2015):15923-15929,
https://doi.org/10.1039/c4ra13391a .,
https://hdl.handle.net/21.15107/rcub_dais_3354 .

TY  - JOUR
AU  - Lačnjevac, Uroš
AU  - Jović, Borka
AU  - Gajić Krstajić, Ljiljana
AU  - Kovač, Janez
AU  - Jović, Vladimir
AU  - Krstajić, Nedeljko
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5725
AB  - The aim of this work was to investigate the possibility of preparation of the composite Cr–MoO2 coatings onto steel and titanium substrates as cathode materials with high selective properties which imply the suppression of hypochlorite reduction as a side reaction during hypochlorite commercial production. The electrodes were prepared by simultaneous deposition of chromium and suspended MoO2 particles on titanium substrate from acid chromium (VI) bath. The current efficiency for electrodeposition of the composite coatings did not vary significantly with the concentration of suspended MoO2 particles. The content of molybdenum in the deposits was relatively low (0.2–1.5 at.%) and increased with increasing the concentration of suspended MoO2 particles in the bath, in the range from 0 to 10 g dm−3. With further increase in the concentration of MoO2, the content of molybdenum in the coating varied insignificantly.X-ray photoelectron spectroscopy-XPS and EDS analysis were applied to analyze elemental composition and chemical bonding of elements on the surface and in the sub-surface region of obtained coatings. When the concentration of MoO2 particles in the bath was raised above 5 g dm−3, the appearance of the coating changed from the typical pure chromium deposit to needle-like deposit with the appearance of black inclusions on the surface. XPS analysis and corresponding Cr 2p spectra showed the presence of chromium oxide, probably Cr2O3 with Cr(3+) valence state on the surface and in the sub-surface region of Cr–MoO2 coatings.Investigation of the current efficiency for the hydrogen evolution reaction (HER) on Cr–MoO2 cathodes showed that it increased with the increase of the content of MoO2 particles in the coating, exceeding the value of 97% in the solution with the hypochlorite concentration of 0.21 mol dm−3. Under the same conditions, the current efficiency for the HER on Ti and Ti/Cr cathodes is very low (≈20%), and corresponding polarization curves confirmed the fact that the side reaction of hypochlorite reduction takes place in the diffusion-controlled regime on these electrodes. The high selectivity of Cr–MoO2 coating is probably caused by the presence of chromium oxide (hydroxide) formed at the surface of the coating during co-deposition of Cr and MoO2 particles, which prevents hypochlorite reduction on the cathode during the HER.
PB  - Elsevier
T2  - Electrochimica Acta
T1  - Ti substrate coated with composite Cr–MoO2 coatings as highly selective cathode materials in hypochlorite production
EP  - 42
SP  - 34
VL  - 96
DO  - 10.1016/j.electacta.2013.02.086
UR  - https://hdl.handle.net/21.15107/rcub_dais_358
ER  - 

@article{
author = "Lačnjevac, Uroš and Jović, Borka and Gajić Krstajić, Ljiljana and Kovač, Janez and Jović, Vladimir and Krstajić, Nedeljko",
year = "2013",
abstract = "The aim of this work was to investigate the possibility of preparation of the composite Cr–MoO2 coatings onto steel and titanium substrates as cathode materials with high selective properties which imply the suppression of hypochlorite reduction as a side reaction during hypochlorite commercial production. The electrodes were prepared by simultaneous deposition of chromium and suspended MoO2 particles on titanium substrate from acid chromium (VI) bath. The current efficiency for electrodeposition of the composite coatings did not vary significantly with the concentration of suspended MoO2 particles. The content of molybdenum in the deposits was relatively low (0.2–1.5 at.%) and increased with increasing the concentration of suspended MoO2 particles in the bath, in the range from 0 to 10 g dm−3. With further increase in the concentration of MoO2, the content of molybdenum in the coating varied insignificantly.X-ray photoelectron spectroscopy-XPS and EDS analysis were applied to analyze elemental composition and chemical bonding of elements on the surface and in the sub-surface region of obtained coatings. When the concentration of MoO2 particles in the bath was raised above 5 g dm−3, the appearance of the coating changed from the typical pure chromium deposit to needle-like deposit with the appearance of black inclusions on the surface. XPS analysis and corresponding Cr 2p spectra showed the presence of chromium oxide, probably Cr2O3 with Cr(3+) valence state on the surface and in the sub-surface region of Cr–MoO2 coatings.Investigation of the current efficiency for the hydrogen evolution reaction (HER) on Cr–MoO2 cathodes showed that it increased with the increase of the content of MoO2 particles in the coating, exceeding the value of 97% in the solution with the hypochlorite concentration of 0.21 mol dm−3. Under the same conditions, the current efficiency for the HER on Ti and Ti/Cr cathodes is very low (≈20%), and corresponding polarization curves confirmed the fact that the side reaction of hypochlorite reduction takes place in the diffusion-controlled regime on these electrodes. The high selectivity of Cr–MoO2 coating is probably caused by the presence of chromium oxide (hydroxide) formed at the surface of the coating during co-deposition of Cr and MoO2 particles, which prevents hypochlorite reduction on the cathode during the HER.",
publisher = "Elsevier",
journal = "Electrochimica Acta",
title = "Ti substrate coated with composite Cr–MoO2 coatings as highly selective cathode materials in hypochlorite production",
pages = "42-34",
volume = "96",
doi = "10.1016/j.electacta.2013.02.086",
url = "https://hdl.handle.net/21.15107/rcub_dais_358"
}

Lačnjevac, U., Jović, B., Gajić Krstajić, L., Kovač, J., Jović, V.,& Krstajić, N.. (2013). Ti substrate coated with composite Cr–MoO2 coatings as highly selective cathode materials in hypochlorite production. in Electrochimica Acta
Elsevier., 96, 34-42.
https://doi.org/10.1016/j.electacta.2013.02.086
https://hdl.handle.net/21.15107/rcub_dais_358

Lačnjevac U, Jović B, Gajić Krstajić L, Kovač J, Jović V, Krstajić N. Ti substrate coated with composite Cr–MoO2 coatings as highly selective cathode materials in hypochlorite production. in Electrochimica Acta. 2013;96:34-42.
doi:10.1016/j.electacta.2013.02.086
https://hdl.handle.net/21.15107/rcub_dais_358 .

Lačnjevac, Uroš, Jović, Borka, Gajić Krstajić, Ljiljana, Kovač, Janez, Jović, Vladimir, Krstajić, Nedeljko, "Ti substrate coated with composite Cr–MoO2 coatings as highly selective cathode materials in hypochlorite production" in Electrochimica Acta, 96 (2013):34-42,
https://doi.org/10.1016/j.electacta.2013.02.086 .,
https://hdl.handle.net/21.15107/rcub_dais_358 .

TY  - JOUR
AU  - Gorenšek, Marija
AU  - Gorjanc, Marija
AU  - Bukošek, Vili
AU  - Kovač, Janez
AU  - Jovančić, Petar
AU  - Mihailović, Darka
PY  - 2010
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5597
AB  - In this work, the antibacterial and other properties of polyester fabrics previously functionalized by corona and/or silver nano particles have been studied. Corona air plasma was used as a pretreatment of raw, washed and washed-thermostabilized polyester fabrics to increase the adhesion of nano silver particles resulting in an excellent antibacterial effect. X-ray photoelectron spectroscopy was applied to analyze the surface composition and chemical bonding of the surface atoms on untreated and treated fabrics. The surface morphological changes of polyester fibers were observed by scanning electron microscopy (SEM). The quantity of silver on the polyester fabrics was determined by the use of the inductively coupled plasma-atomic emission spectrometry method. The antimicrobial properties of functionalized polyester fabrics were tested according to American Society for Testing and Materials ASTM Designation: E 2149-01. Additionally, the dyeing of polyester fabrics with selected disperse dye as well as capillary action tests were performed to confirm the chemical and morphological changes of polyester fibers after corona treatment. Considerable differences in surface composition were found between the raw and washed or washed-thermostabilized fabrics. The surface of raw fabrics is richer in carbon and the concentrations of the C—O and O—C=O groups are lower than on the other samples. An opposite effect is observed for washed and washed thermostabilized fabrics. SEM analyses show that the plasma treatment also affects the surface morphology. The chemical surface composition and morphology are highly related to the hydrophobicity and hydrophylicity, and the achievement of better nano silver adhesion and enhanced dyeing and antimicrobial properties of differently prepared corona plasma-treated polyester fabrics. Therefore, corona air-treated raw polyester fabrics demonstrated optimum antimicrobial properties due to the excellent adhesion of nano silver.
PB  - SAGE Publications
T2  - Textile Research Journal
T1  - Functionalization of PET Fabrics by Corona and Nano Silver
EP  - 262
IS  - 3
SP  - 253
VL  - 80
DO  - 10.1177/0040517509105275
ER  - 

@article{
author = "Gorenšek, Marija and Gorjanc, Marija and Bukošek, Vili and Kovač, Janez and Jovančić, Petar and Mihailović, Darka",
year = "2010",
abstract = "In this work, the antibacterial and other properties of polyester fabrics previously functionalized by corona and/or silver nano particles have been studied. Corona air plasma was used as a pretreatment of raw, washed and washed-thermostabilized polyester fabrics to increase the adhesion of nano silver particles resulting in an excellent antibacterial effect. X-ray photoelectron spectroscopy was applied to analyze the surface composition and chemical bonding of the surface atoms on untreated and treated fabrics. The surface morphological changes of polyester fibers were observed by scanning electron microscopy (SEM). The quantity of silver on the polyester fabrics was determined by the use of the inductively coupled plasma-atomic emission spectrometry method. The antimicrobial properties of functionalized polyester fabrics were tested according to American Society for Testing and Materials ASTM Designation: E 2149-01. Additionally, the dyeing of polyester fabrics with selected disperse dye as well as capillary action tests were performed to confirm the chemical and morphological changes of polyester fibers after corona treatment. Considerable differences in surface composition were found between the raw and washed or washed-thermostabilized fabrics. The surface of raw fabrics is richer in carbon and the concentrations of the C—O and O—C=O groups are lower than on the other samples. An opposite effect is observed for washed and washed thermostabilized fabrics. SEM analyses show that the plasma treatment also affects the surface morphology. The chemical surface composition and morphology are highly related to the hydrophobicity and hydrophylicity, and the achievement of better nano silver adhesion and enhanced dyeing and antimicrobial properties of differently prepared corona plasma-treated polyester fabrics. Therefore, corona air-treated raw polyester fabrics demonstrated optimum antimicrobial properties due to the excellent adhesion of nano silver.",
publisher = "SAGE Publications",
journal = "Textile Research Journal",
title = "Functionalization of PET Fabrics by Corona and Nano Silver",
pages = "262-253",
number = "3",
volume = "80",
doi = "10.1177/0040517509105275"
}

Gorenšek, M., Gorjanc, M., Bukošek, V., Kovač, J., Jovančić, P.,& Mihailović, D.. (2010). Functionalization of PET Fabrics by Corona and Nano Silver. in Textile Research Journal
SAGE Publications., 80(3), 253-262.
https://doi.org/10.1177/0040517509105275

Gorenšek M, Gorjanc M, Bukošek V, Kovač J, Jovančić P, Mihailović D. Functionalization of PET Fabrics by Corona and Nano Silver. in Textile Research Journal. 2010;80(3):253-262.
doi:10.1177/0040517509105275 .

Gorenšek, Marija, Gorjanc, Marija, Bukošek, Vili, Kovač, Janez, Jovančić, Petar, Mihailović, Darka, "Functionalization of PET Fabrics by Corona and Nano Silver" in Textile Research Journal, 80, no. 3 (2010):253-262,
https://doi.org/10.1177/0040517509105275 . .

TY  - JOUR
AU  - Rajić, Nevenka
AU  - Stojaković, Đorđe
AU  - Jevtić, Sanja
AU  - Zabukovec-Logar, Nataša
AU  - Kovač, Janez
AU  - Kaučič, Venčeslav
PY  - 2009
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1467
AB  - The natural zeolite tuff from the Vranjska Banja deposit (Serbia) has been studied as sorbent for Mn(II) ions from aqueous solutions. The zeolite sample containing mainly clinoptilolite (more than 70%) removes Mn(II) ions by ion-exchange process, which was confirmed by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray analysis (EDXS). XPS showed that there is no surface accumulation of Mn but an almost uniform distribution inside the sorbent; EDXS confirmed that Mn(II) replaced the clinoptilolite Na counter ions. The sorption isotherms were studied at 298 K by batch experiments showing that the Mn(II) removal is best described by the Langmuir-Freundlich or Sips model. The kinetics followed the pseudo-second-order model, the activation energy being 128 kJ mol(-1). The intra-particle diffusion is not the rate-controlling step in the sorption of Mn(II) on clinoptilolite. Thermodynamic data suggest spontaneity of the endothermic ion-exchange process in the 298-338 K range.
PB  - Elsevier, Amsterdam
T2  - Journal of Hazardous Materials
T1  - Removal of aqueous manganese using the natural zeolitic tuff from the Vranjska Banja deposit in Serbia
EP  - 1457
IS  - 2-3
SP  - 1450
VL  - 172
DO  - 10.1016/j.jhazmat.2009.08.011
ER  - 

@article{
author = "Rajić, Nevenka and Stojaković, Đorđe and Jevtić, Sanja and Zabukovec-Logar, Nataša and Kovač, Janez and Kaučič, Venčeslav",
year = "2009",
abstract = "The natural zeolite tuff from the Vranjska Banja deposit (Serbia) has been studied as sorbent for Mn(II) ions from aqueous solutions. The zeolite sample containing mainly clinoptilolite (more than 70%) removes Mn(II) ions by ion-exchange process, which was confirmed by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray analysis (EDXS). XPS showed that there is no surface accumulation of Mn but an almost uniform distribution inside the sorbent; EDXS confirmed that Mn(II) replaced the clinoptilolite Na counter ions. The sorption isotherms were studied at 298 K by batch experiments showing that the Mn(II) removal is best described by the Langmuir-Freundlich or Sips model. The kinetics followed the pseudo-second-order model, the activation energy being 128 kJ mol(-1). The intra-particle diffusion is not the rate-controlling step in the sorption of Mn(II) on clinoptilolite. Thermodynamic data suggest spontaneity of the endothermic ion-exchange process in the 298-338 K range.",
publisher = "Elsevier, Amsterdam",
journal = "Journal of Hazardous Materials",
title = "Removal of aqueous manganese using the natural zeolitic tuff from the Vranjska Banja deposit in Serbia",
pages = "1457-1450",
number = "2-3",
volume = "172",
doi = "10.1016/j.jhazmat.2009.08.011"
}

Rajić, N., Stojaković, Đ., Jevtić, S., Zabukovec-Logar, N., Kovač, J.,& Kaučič, V.. (2009). Removal of aqueous manganese using the natural zeolitic tuff from the Vranjska Banja deposit in Serbia. in Journal of Hazardous Materials
Elsevier, Amsterdam., 172(2-3), 1450-1457.
https://doi.org/10.1016/j.jhazmat.2009.08.011

Rajić N, Stojaković Đ, Jevtić S, Zabukovec-Logar N, Kovač J, Kaučič V. Removal of aqueous manganese using the natural zeolitic tuff from the Vranjska Banja deposit in Serbia. in Journal of Hazardous Materials. 2009;172(2-3):1450-1457.
doi:10.1016/j.jhazmat.2009.08.011 .

Rajić, Nevenka, Stojaković, Đorđe, Jevtić, Sanja, Zabukovec-Logar, Nataša, Kovač, Janez, Kaučič, Venčeslav, "Removal of aqueous manganese using the natural zeolitic tuff from the Vranjska Banja deposit in Serbia" in Journal of Hazardous Materials, 172, no. 2-3 (2009):1450-1457,
https://doi.org/10.1016/j.jhazmat.2009.08.011 . .