TY  - JOUR
AU  - Mravik, Željko
AU  - Bajuk-Bogdanović, Danica V.
AU  - Jovanović, Sonja
AU  - Rmuš, Jelena
AU  - Olejniczak, Andrzej
AU  - Mraković, Ana Đ.
AU  - Lazarević, Jasmina
AU  - Uskoković-Marković, Snežana
AU  - Lazarević, Nenad
AU  - Skuratov, Vladimir A.
AU  - Jovanović, Zoran
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10376
AB  - Ion beam irradiation is a versatile tool for structural modification andengineering of new materials. In this study, 12-tungstophosphoric acid (WPA)films of different thickness were spin-coated on platinized silicon substrate andirradiated with low energy hydrogen ions (10 keV) and swift heavy ions (Bi,Xe, and V) with energies up to 710 MeV. The different energy/fluence combi-nations allowed controllable structural changes that were investigated in detailusing Raman and Infrared spectroscopy. For 120-nm-thick WPA samples, theirradiation led to the decrease of intensity of the skeletal and W-Oc-W bands ofKeggin anion in order: Bi < V < Xe (for their applied energy/fluence combina-tion). Also, symmetry change of Keggin anion similar to the one observed inthe case of Keggin anions interacting with the supports was observed. For theselected ion beam irradiation parameters, xenon ion beam induced transforma-tion of WPA to polytungstate. For 20-μm-thick WPA samples, the irradiationwith hydrogen ion beam induced changes of skeletal vibrations and increasedindividualistic behavior of Keggin anions. As the fluence increased, theamount of the Keggin anions partially transformed to bronze also increased.Irradiation with vanadium also caused transformation to bronze-like structurebut with higher ratio of terminal W=Odbonds. The overall results show clearReceived: 9 February 2022Revised: 17 June 2022Accepted: 5 July 2022DOI: 10.1002/jrs.6423J Raman Spectrosc.2022;1–11.wileyonlinelibrary.com/journal/jrs© 2022 John Wiley & Sons Ltd.1correlation between degree of structural modification of WPA and thecalculated displacement per atom value. These results open possibilities forengineering new catalytically active structures of polyoxometalates with thehelp of ion beams.
T2  - Journal of Raman Spectroscopy
T1  - Modification of Keggin anion structure with ion beams—A new spectroscopic insights into the effects of keV- and MeV-ion beam irradiation on 12-tungstophosphoric acid
DO  - 10.1002/jrs.6423
ER  - 

@article{
author = "Mravik, Željko and Bajuk-Bogdanović, Danica V. and Jovanović, Sonja and Rmuš, Jelena and Olejniczak, Andrzej and Mraković, Ana Đ. and Lazarević, Jasmina and Uskoković-Marković, Snežana and Lazarević, Nenad and Skuratov, Vladimir A. and Jovanović, Zoran",
year = "2022",
abstract = "Ion beam irradiation is a versatile tool for structural modification andengineering of new materials. In this study, 12-tungstophosphoric acid (WPA)films of different thickness were spin-coated on platinized silicon substrate andirradiated with low energy hydrogen ions (10 keV) and swift heavy ions (Bi,Xe, and V) with energies up to 710 MeV. The different energy/fluence combi-nations allowed controllable structural changes that were investigated in detailusing Raman and Infrared spectroscopy. For 120-nm-thick WPA samples, theirradiation led to the decrease of intensity of the skeletal and W-Oc-W bands ofKeggin anion in order: Bi < V < Xe (for their applied energy/fluence combina-tion). Also, symmetry change of Keggin anion similar to the one observed inthe case of Keggin anions interacting with the supports was observed. For theselected ion beam irradiation parameters, xenon ion beam induced transforma-tion of WPA to polytungstate. For 20-μm-thick WPA samples, the irradiationwith hydrogen ion beam induced changes of skeletal vibrations and increasedindividualistic behavior of Keggin anions. As the fluence increased, theamount of the Keggin anions partially transformed to bronze also increased.Irradiation with vanadium also caused transformation to bronze-like structurebut with higher ratio of terminal W=Odbonds. The overall results show clearReceived: 9 February 2022Revised: 17 June 2022Accepted: 5 July 2022DOI: 10.1002/jrs.6423J Raman Spectrosc.2022;1–11.wileyonlinelibrary.com/journal/jrs© 2022 John Wiley & Sons Ltd.1correlation between degree of structural modification of WPA and thecalculated displacement per atom value. These results open possibilities forengineering new catalytically active structures of polyoxometalates with thehelp of ion beams.",
journal = "Journal of Raman Spectroscopy",
title = "Modification of Keggin anion structure with ion beams—A new spectroscopic insights into the effects of keV- and MeV-ion beam irradiation on 12-tungstophosphoric acid",
doi = "10.1002/jrs.6423"
}

Mravik, Ž., Bajuk-Bogdanović, D. V., Jovanović, S., Rmuš, J., Olejniczak, A., Mraković, A. Đ., Lazarević, J., Uskoković-Marković, S., Lazarević, N., Skuratov, V. A.,& Jovanović, Z.. (2022). Modification of Keggin anion structure with ion beams—A new spectroscopic insights into the effects of keV- and MeV-ion beam irradiation on 12-tungstophosphoric acid. in Journal of Raman Spectroscopy.
https://doi.org/10.1002/jrs.6423

Mravik Ž, Bajuk-Bogdanović DV, Jovanović S, Rmuš J, Olejniczak A, Mraković AĐ, Lazarević J, Uskoković-Marković S, Lazarević N, Skuratov VA, Jovanović Z. Modification of Keggin anion structure with ion beams—A new spectroscopic insights into the effects of keV- and MeV-ion beam irradiation on 12-tungstophosphoric acid. in Journal of Raman Spectroscopy. 2022;.
doi:10.1002/jrs.6423 .

Mravik, Željko, Bajuk-Bogdanović, Danica V., Jovanović, Sonja, Rmuš, Jelena, Olejniczak, Andrzej, Mraković, Ana Đ., Lazarević, Jasmina, Uskoković-Marković, Snežana, Lazarević, Nenad, Skuratov, Vladimir A., Jovanović, Zoran, "Modification of Keggin anion structure with ion beams—A new spectroscopic insights into the effects of keV- and MeV-ion beam irradiation on 12-tungstophosphoric acid" in Journal of Raman Spectroscopy (2022),
https://doi.org/10.1002/jrs.6423 . .

TY  - JOUR
AU  - Jovanović, Zoran M.
AU  - Mravik, Željko
AU  - Bajuk-Bogdanović, Danica V.
AU  - Jovanović, Sonja
AU  - Marković, Smilja
AU  - Vujković, Milica
AU  - Kovač, Janez
AU  - Vengust, Damjan
AU  - Uskoković-Marković, Snežana
AU  - Holclajtner-Antunović, Ivanka D.
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8520
AB  - In the present study we investigated the interaction between 12-tungstophosphoric acid (WPA) and graphene oxide (GO) in their nanocomposite by utilizing the loading of WPA as an intrinsic parameter for interaction tuning. The Fourier-transform infrared spectroscopy, temperature-programmed desorption, X-ray photoelectron spectroscopy, zeta-potential measurements, thermogravimetric analysis, X-ray diffraction, Raman spectroscopy and transmission electron microscopy methods revealed that ∼5–13 wt% of WPA represents critical loading that separates two distinct contributions to GO-WPA interaction. This was explained by the self-limiting nature of GO-WPA interaction, initially controlled by high dispersion of WPA on GO (up to 13 wt%), that is eventually overpowered by WPA-WPA interaction as loading increases. As a result, the WPA agglomerates are being formed because of which the hybrid character of the nanocomposite diminishes, i.e., the properties of independent components start to be manifested to greater extent. The obtained results provide an important framework for considering possible outcomes in other 2D-0D systems, whose interaction is relevant both from fundamental and applicative point of view. Thus, the GO/WPA nanocomposite illustrates how the interactions between the components can be used for tuning the properties of nanocomposite as a whole. © 2019 Elsevier Ltd
T2  - Carbon
T1  - Self-limiting interactions in 2D–0D systems: A case study of graphene oxide and 12-tungstophosphoric acid nanocomposite
VL  - 156
SP  - 166
EP  - 178
DO  - 10.1016/j.carbon.2019.09.072
ER  - 

@article{
author = "Jovanović, Zoran M. and Mravik, Željko and Bajuk-Bogdanović, Danica V. and Jovanović, Sonja and Marković, Smilja and Vujković, Milica and Kovač, Janez and Vengust, Damjan and Uskoković-Marković, Snežana and Holclajtner-Antunović, Ivanka D.",
year = "2020",
abstract = "In the present study we investigated the interaction between 12-tungstophosphoric acid (WPA) and graphene oxide (GO) in their nanocomposite by utilizing the loading of WPA as an intrinsic parameter for interaction tuning. The Fourier-transform infrared spectroscopy, temperature-programmed desorption, X-ray photoelectron spectroscopy, zeta-potential measurements, thermogravimetric analysis, X-ray diffraction, Raman spectroscopy and transmission electron microscopy methods revealed that ∼5–13 wt% of WPA represents critical loading that separates two distinct contributions to GO-WPA interaction. This was explained by the self-limiting nature of GO-WPA interaction, initially controlled by high dispersion of WPA on GO (up to 13 wt%), that is eventually overpowered by WPA-WPA interaction as loading increases. As a result, the WPA agglomerates are being formed because of which the hybrid character of the nanocomposite diminishes, i.e., the properties of independent components start to be manifested to greater extent. The obtained results provide an important framework for considering possible outcomes in other 2D-0D systems, whose interaction is relevant both from fundamental and applicative point of view. Thus, the GO/WPA nanocomposite illustrates how the interactions between the components can be used for tuning the properties of nanocomposite as a whole. © 2019 Elsevier Ltd",
journal = "Carbon",
title = "Self-limiting interactions in 2D–0D systems: A case study of graphene oxide and 12-tungstophosphoric acid nanocomposite",
volume = "156",
pages = "166-178",
doi = "10.1016/j.carbon.2019.09.072"
}

Jovanović, Z. M., Mravik, Ž., Bajuk-Bogdanović, D. V., Jovanović, S., Marković, S., Vujković, M., Kovač, J., Vengust, D., Uskoković-Marković, S.,& Holclajtner-Antunović, I. D.. (2020). Self-limiting interactions in 2D–0D systems: A case study of graphene oxide and 12-tungstophosphoric acid nanocomposite. in Carbon, 156, 166-178.
https://doi.org/10.1016/j.carbon.2019.09.072

Jovanović ZM, Mravik Ž, Bajuk-Bogdanović DV, Jovanović S, Marković S, Vujković M, Kovač J, Vengust D, Uskoković-Marković S, Holclajtner-Antunović ID. Self-limiting interactions in 2D–0D systems: A case study of graphene oxide and 12-tungstophosphoric acid nanocomposite. in Carbon. 2020;156:166-178.
doi:10.1016/j.carbon.2019.09.072 .

Jovanović, Zoran M., Mravik, Željko, Bajuk-Bogdanović, Danica V., Jovanović, Sonja, Marković, Smilja, Vujković, Milica, Kovač, Janez, Vengust, Damjan, Uskoković-Marković, Snežana, Holclajtner-Antunović, Ivanka D., "Self-limiting interactions in 2D–0D systems: A case study of graphene oxide and 12-tungstophosphoric acid nanocomposite" in Carbon, 156 (2020):166-178,
https://doi.org/10.1016/j.carbon.2019.09.072 . .

TY  - JOUR
AU  - Bajuk-Bogdanović, Danica V.
AU  - Holclajtner-Antunović, Ivanka D.
AU  - Jovanović, Zoran M.
AU  - Mravik, Željko
AU  - Krstić, Jugoslav B.
AU  - Uskoković-Marković, Snežana
AU  - Vujković, Milica
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8500
AB  - The synergistic effects between two Keggin-type heteropoly acids (HPAs) and carbon surface were examined and elucidated. An improved high rate capability (and potential high capacitor electrode for supercapacitors) of the hybrid materials, obtained by anchoring of α-dodecamolybdophosphoric (MoPA), α-dodecatungstophosphoric (WPA), and their mixture to activated carbon (AC), was achieved through the different mechanism of interaction. In order to elaborate this, a detailed analysis of AC-HPA composites has been performed by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, temperature-programmed desorption (TPD), Fourier-transform infrared spectroscopy (FTIR), micro Raman spectroscopy, and zeta potential measurements. The zeta potential measurements revealed positive charge of carbon surface thus indicating attractive interactions with negatively charged Keggin anion. The surface analysis has shown that WPA spontaneously reduces the carbon surface, while interaction with MoPA leads to its oxidation. As the consequence of the tailoring of the functional groups at carbon surface through HPAs’ action, the distortion of cyclic voltammograms (CVs) decreased in the following order: AC-MoPA, AC-MoPA-WPA, and AC-WPA. A prominent rectangular shape of AC-WPA, even at an extremely high scan rate of 400 mVs−1, was measured, which is rarely demonstrated for carbon-based composites. By applying the theory of electrode potentials, the HPA-AC synergistic effect was explained and discussed in terms of charge storage improvement of HPA-modified carbon. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
T2  - Journal of Solid State Electrochemistry
T1  - Tailoring the electrochemical charge storage properties of carbonaceous support by redox properties of heteropoly acids: where does the synergy come from?
VL  - 23
IS  - 9
SP  - 2747
EP  - 2758
DO  - 10.1007/s10008-019-04369-4
ER  - 

@article{
author = "Bajuk-Bogdanović, Danica V. and Holclajtner-Antunović, Ivanka D. and Jovanović, Zoran M. and Mravik, Željko and Krstić, Jugoslav B. and Uskoković-Marković, Snežana and Vujković, Milica",
year = "2019",
abstract = "The synergistic effects between two Keggin-type heteropoly acids (HPAs) and carbon surface were examined and elucidated. An improved high rate capability (and potential high capacitor electrode for supercapacitors) of the hybrid materials, obtained by anchoring of α-dodecamolybdophosphoric (MoPA), α-dodecatungstophosphoric (WPA), and their mixture to activated carbon (AC), was achieved through the different mechanism of interaction. In order to elaborate this, a detailed analysis of AC-HPA composites has been performed by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, temperature-programmed desorption (TPD), Fourier-transform infrared spectroscopy (FTIR), micro Raman spectroscopy, and zeta potential measurements. The zeta potential measurements revealed positive charge of carbon surface thus indicating attractive interactions with negatively charged Keggin anion. The surface analysis has shown that WPA spontaneously reduces the carbon surface, while interaction with MoPA leads to its oxidation. As the consequence of the tailoring of the functional groups at carbon surface through HPAs’ action, the distortion of cyclic voltammograms (CVs) decreased in the following order: AC-MoPA, AC-MoPA-WPA, and AC-WPA. A prominent rectangular shape of AC-WPA, even at an extremely high scan rate of 400 mVs−1, was measured, which is rarely demonstrated for carbon-based composites. By applying the theory of electrode potentials, the HPA-AC synergistic effect was explained and discussed in terms of charge storage improvement of HPA-modified carbon. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.",
journal = "Journal of Solid State Electrochemistry",
title = "Tailoring the electrochemical charge storage properties of carbonaceous support by redox properties of heteropoly acids: where does the synergy come from?",
volume = "23",
number = "9",
pages = "2747-2758",
doi = "10.1007/s10008-019-04369-4"
}

Bajuk-Bogdanović, D. V., Holclajtner-Antunović, I. D., Jovanović, Z. M., Mravik, Ž., Krstić, J. B., Uskoković-Marković, S.,& Vujković, M.. (2019). Tailoring the electrochemical charge storage properties of carbonaceous support by redox properties of heteropoly acids: where does the synergy come from?. in Journal of Solid State Electrochemistry, 23(9), 2747-2758.
https://doi.org/10.1007/s10008-019-04369-4

Bajuk-Bogdanović DV, Holclajtner-Antunović ID, Jovanović ZM, Mravik Ž, Krstić JB, Uskoković-Marković S, Vujković M. Tailoring the electrochemical charge storage properties of carbonaceous support by redox properties of heteropoly acids: where does the synergy come from?. in Journal of Solid State Electrochemistry. 2019;23(9):2747-2758.
doi:10.1007/s10008-019-04369-4 .

Bajuk-Bogdanović, Danica V., Holclajtner-Antunović, Ivanka D., Jovanović, Zoran M., Mravik, Željko, Krstić, Jugoslav B., Uskoković-Marković, Snežana, Vujković, Milica, "Tailoring the electrochemical charge storage properties of carbonaceous support by redox properties of heteropoly acids: where does the synergy come from?" in Journal of Solid State Electrochemistry, 23, no. 9 (2019):2747-2758,
https://doi.org/10.1007/s10008-019-04369-4 . .

TY  - JOUR
AU  - Jovanović, Svetlana P.
AU  - Holclajtner-Antunović, Ivanka D.
AU  - Uskoković-Marković, Snežana
AU  - Bajuk-Bogdanović, Danica V.
AU  - Pavlović, Vladimir B.
AU  - Tošić, Dragana
AU  - Milenković, Marina
AU  - Todorović-Marković, Biljana
PY  - 2018
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7611
AB  - © 2018 Antibacterial properties of graphene oxide (GO) have been studied extensively in the last few years, while for polyoxometalates there are just a few researches. Herein, we prepared nanocomposites of GO and different amounts of 12-molybdophosphoric acid (MoPA) and analyzed their antibacterial activity and both structural and morphological properties. In nanocomposites with higher amounts of MoPA, graphene sheets were significantly changed with disrupted flat, graphene-like morphology of GO. In the nanocomposites with low MoPA content, flat GO morphology was preserved. Additionally, structural analyses showed some changes in symmetry of the Keggin anion as a consequence of interactions between GO and MoPA, the increase in structural disorder and the lowering of electron density in GO structure due to interaction with MoPA. We have studied antibacterial properties on the gram-positive: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis; and the gram-negative bacteria: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella abony. Only a mild antibacterial effect of GO and nanocomposites with low amount of MoPA against Bacillus subtilis was observed, while the rest of analyzed materials did not show any antibacterial activity.
T2  - Materials Chemistry and Physics
T1  - Modification of graphene oxide surfaces with 12-molybdophosphoric acid: Structural and antibacterial study
VL  - 213
SP  - 157
EP  - 167
DO  - 10.1016/j.matchemphys.2018.04.011
ER  - 

@article{
author = "Jovanović, Svetlana P. and Holclajtner-Antunović, Ivanka D. and Uskoković-Marković, Snežana and Bajuk-Bogdanović, Danica V. and Pavlović, Vladimir B. and Tošić, Dragana and Milenković, Marina and Todorović-Marković, Biljana",
year = "2018",
abstract = "© 2018 Antibacterial properties of graphene oxide (GO) have been studied extensively in the last few years, while for polyoxometalates there are just a few researches. Herein, we prepared nanocomposites of GO and different amounts of 12-molybdophosphoric acid (MoPA) and analyzed their antibacterial activity and both structural and morphological properties. In nanocomposites with higher amounts of MoPA, graphene sheets were significantly changed with disrupted flat, graphene-like morphology of GO. In the nanocomposites with low MoPA content, flat GO morphology was preserved. Additionally, structural analyses showed some changes in symmetry of the Keggin anion as a consequence of interactions between GO and MoPA, the increase in structural disorder and the lowering of electron density in GO structure due to interaction with MoPA. We have studied antibacterial properties on the gram-positive: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis; and the gram-negative bacteria: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella abony. Only a mild antibacterial effect of GO and nanocomposites with low amount of MoPA against Bacillus subtilis was observed, while the rest of analyzed materials did not show any antibacterial activity.",
journal = "Materials Chemistry and Physics",
title = "Modification of graphene oxide surfaces with 12-molybdophosphoric acid: Structural and antibacterial study",
volume = "213",
pages = "157-167",
doi = "10.1016/j.matchemphys.2018.04.011"
}

Jovanović, S. P., Holclajtner-Antunović, I. D., Uskoković-Marković, S., Bajuk-Bogdanović, D. V., Pavlović, V. B., Tošić, D., Milenković, M.,& Todorović-Marković, B.. (2018). Modification of graphene oxide surfaces with 12-molybdophosphoric acid: Structural and antibacterial study. in Materials Chemistry and Physics, 213, 157-167.
https://doi.org/10.1016/j.matchemphys.2018.04.011

Jovanović SP, Holclajtner-Antunović ID, Uskoković-Marković S, Bajuk-Bogdanović DV, Pavlović VB, Tošić D, Milenković M, Todorović-Marković B. Modification of graphene oxide surfaces with 12-molybdophosphoric acid: Structural and antibacterial study. in Materials Chemistry and Physics. 2018;213:157-167.
doi:10.1016/j.matchemphys.2018.04.011 .

Jovanović, Svetlana P., Holclajtner-Antunović, Ivanka D., Uskoković-Marković, Snežana, Bajuk-Bogdanović, Danica V., Pavlović, Vladimir B., Tošić, Dragana, Milenković, Marina, Todorović-Marković, Biljana, "Modification of graphene oxide surfaces with 12-molybdophosphoric acid: Structural and antibacterial study" in Materials Chemistry and Physics, 213 (2018):157-167,
https://doi.org/10.1016/j.matchemphys.2018.04.011 . .