TY  - JOUR
AU  - Marković, Zoran M.
AU  - Budimir Filimonović, Milica
AU  - Milivojević, Dušan
AU  - Kovač, Janez
AU  - Todorović-Marković, Biljana
PY  - 2024
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12997
AB  - The cost of treatment of antibiotic-resistant pathogens is on the level of tens of billions of dollars at the moment. It is of special interest to reduce or solve this problem using antimicrobial coatings, especially in hospitals or other healthcare facilities. The bacteria can transfer from medical staff or contaminated surfaces to patients. In this paper, we focused our attention on the antibacterial and antibiofouling activities of two types of photodynamic polyurethane composite films doped with carbon polymerized dots (CPDs) and fullerene C60. Detailed atomic force, electrostatic force and viscoelastic microscopy revealed topology, nanoelectrical and nanomechanical properties of used fillers and composites. A relationship between the electronic structure of the nanocarbon fillers and the antibacterial and antibiofouling activities of the composites was established. Thorough spectroscopic analysis of reactive oxygen species (ROS) generation was conducted for both composite films, and it was found that both of them were potent antibacterial agents against nosocomial bacteria (Klebsiela pneumoniae, Proteus mirabilis, Salmonela enterica, Enterococcus faecalis, Enterococcus epidermis and Pseudomonas aeruginosa). Antibiofouling testing of composite films indicated that the CPDs/PU composite films eradicated almost completely the biofilms of Pseudomonas aeruginosa and Staphylococcus aureus and about 50% of Escherichia coli biofilms.
T2  - Journal of Functional Biomaterials
T1  - Antibacterial and Antibiofouling Activities of Carbon Polymerized Dots/Polyurethane and C60/Polyurethane Composite Films
VL  - 15
IS  - 3
SP  - 73
DO  - 10.3390/jfb15030073
ER  - 

@article{
author = "Marković, Zoran M. and Budimir Filimonović, Milica and Milivojević, Dušan and Kovač, Janez and Todorović-Marković, Biljana",
year = "2024",
abstract = "The cost of treatment of antibiotic-resistant pathogens is on the level of tens of billions of dollars at the moment. It is of special interest to reduce or solve this problem using antimicrobial coatings, especially in hospitals or other healthcare facilities. The bacteria can transfer from medical staff or contaminated surfaces to patients. In this paper, we focused our attention on the antibacterial and antibiofouling activities of two types of photodynamic polyurethane composite films doped with carbon polymerized dots (CPDs) and fullerene C60. Detailed atomic force, electrostatic force and viscoelastic microscopy revealed topology, nanoelectrical and nanomechanical properties of used fillers and composites. A relationship between the electronic structure of the nanocarbon fillers and the antibacterial and antibiofouling activities of the composites was established. Thorough spectroscopic analysis of reactive oxygen species (ROS) generation was conducted for both composite films, and it was found that both of them were potent antibacterial agents against nosocomial bacteria (Klebsiela pneumoniae, Proteus mirabilis, Salmonela enterica, Enterococcus faecalis, Enterococcus epidermis and Pseudomonas aeruginosa). Antibiofouling testing of composite films indicated that the CPDs/PU composite films eradicated almost completely the biofilms of Pseudomonas aeruginosa and Staphylococcus aureus and about 50% of Escherichia coli biofilms.",
journal = "Journal of Functional Biomaterials",
title = "Antibacterial and Antibiofouling Activities of Carbon Polymerized Dots/Polyurethane and C60/Polyurethane Composite Films",
volume = "15",
number = "3",
pages = "73",
doi = "10.3390/jfb15030073"
}

Marković, Z. M., Budimir Filimonović, M., Milivojević, D., Kovač, J.,& Todorović-Marković, B.. (2024). Antibacterial and Antibiofouling Activities of Carbon Polymerized Dots/Polyurethane and C60/Polyurethane Composite Films. in Journal of Functional Biomaterials, 15(3), 73.
https://doi.org/10.3390/jfb15030073

Marković ZM, Budimir Filimonović M, Milivojević D, Kovač J, Todorović-Marković B. Antibacterial and Antibiofouling Activities of Carbon Polymerized Dots/Polyurethane and C60/Polyurethane Composite Films. in Journal of Functional Biomaterials. 2024;15(3):73.
doi:10.3390/jfb15030073 .

Marković, Zoran M., Budimir Filimonović, Milica, Milivojević, Dušan, Kovač, Janez, Todorović-Marković, Biljana, "Antibacterial and Antibiofouling Activities of Carbon Polymerized Dots/Polyurethane and C60/Polyurethane Composite Films" in Journal of Functional Biomaterials, 15, no. 3 (2024):73,
https://doi.org/10.3390/jfb15030073 . .

TY  - JOUR
AU  - Marković, Zoran M.
AU  - Mišović, Aleksandra
AU  - Zmejkoski, Danica
AU  - Zdravković, Nemanja M.
AU  - Kovač, Janez
AU  - Bajuk-Bogdanović, Danica
AU  - Milivojević, Dušan
AU  - Mojsin, Marija
AU  - Stevanović, Milena
AU  - Pavlović, Vladimir B.
AU  - Todorović-Marković, Biljana
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11075
AB  - Nowadays, it is a great challenge to develop new medicines for treating various infectious diseases. The treatment of these diseases is of utmost interest to further prevent the development of multi-drug resistance in different pathogens. Carbon quantum dots, as a new member of the carbon nanomaterials family, can potentially be used as a highly promising visible-light-triggered antibacterial agent. In this work, the results of antibacterial and cytotoxic activities of gamma-ray-irradiated carbon quantum dots are presented. Carbon quantum dots (CQDs) were synthesized from citric acid by a pyrolysis procedure and irradiated by gamma rays at different doses (25, 50, 100 and 200 kGy). Structure, chemical composition and optical properties were investigated by atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, UV-Vis spectrometry and photoluminescence. Structural analysis showed that CQDs have a spherical-like shape and dose-dependent average diameters and heights. Antibacterial tests showed that all irradiated dots had antibacterial activity but CQDs irradiated with dose of 100 kGy had antibacterial activity against all seven pathogen-reference bacterial strains. Gamma-ray-modified CQDs did not show any cytotoxicity toward human fetal-originated MRC-5 cells. Moreover, fluorescence microscopy showed excellent cellular uptake of CQDs irradiated with doses of 25 and 200 kGy into MRC-5 cells.
T2  - Antibiotics
T1  - Employing Gamma-Ray-Modified Carbon Quantum Dots to Combat a Wide Range of Bacteria
VL  - 12
IS  - 5
SP  - 919
DO  - 10.3390/antibiotics12050919
ER  - 

@article{
author = "Marković, Zoran M. and Mišović, Aleksandra and Zmejkoski, Danica and Zdravković, Nemanja M. and Kovač, Janez and Bajuk-Bogdanović, Danica and Milivojević, Dušan and Mojsin, Marija and Stevanović, Milena and Pavlović, Vladimir B. and Todorović-Marković, Biljana",
year = "2023",
abstract = "Nowadays, it is a great challenge to develop new medicines for treating various infectious diseases. The treatment of these diseases is of utmost interest to further prevent the development of multi-drug resistance in different pathogens. Carbon quantum dots, as a new member of the carbon nanomaterials family, can potentially be used as a highly promising visible-light-triggered antibacterial agent. In this work, the results of antibacterial and cytotoxic activities of gamma-ray-irradiated carbon quantum dots are presented. Carbon quantum dots (CQDs) were synthesized from citric acid by a pyrolysis procedure and irradiated by gamma rays at different doses (25, 50, 100 and 200 kGy). Structure, chemical composition and optical properties were investigated by atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, UV-Vis spectrometry and photoluminescence. Structural analysis showed that CQDs have a spherical-like shape and dose-dependent average diameters and heights. Antibacterial tests showed that all irradiated dots had antibacterial activity but CQDs irradiated with dose of 100 kGy had antibacterial activity against all seven pathogen-reference bacterial strains. Gamma-ray-modified CQDs did not show any cytotoxicity toward human fetal-originated MRC-5 cells. Moreover, fluorescence microscopy showed excellent cellular uptake of CQDs irradiated with doses of 25 and 200 kGy into MRC-5 cells.",
journal = "Antibiotics",
title = "Employing Gamma-Ray-Modified Carbon Quantum Dots to Combat a Wide Range of Bacteria",
volume = "12",
number = "5",
pages = "919",
doi = "10.3390/antibiotics12050919"
}

Marković, Z. M., Mišović, A., Zmejkoski, D., Zdravković, N. M., Kovač, J., Bajuk-Bogdanović, D., Milivojević, D., Mojsin, M., Stevanović, M., Pavlović, V. B.,& Todorović-Marković, B.. (2023). Employing Gamma-Ray-Modified Carbon Quantum Dots to Combat a Wide Range of Bacteria. in Antibiotics, 12(5), 919.
https://doi.org/10.3390/antibiotics12050919

Marković ZM, Mišović A, Zmejkoski D, Zdravković NM, Kovač J, Bajuk-Bogdanović D, Milivojević D, Mojsin M, Stevanović M, Pavlović VB, Todorović-Marković B. Employing Gamma-Ray-Modified Carbon Quantum Dots to Combat a Wide Range of Bacteria. in Antibiotics. 2023;12(5):919.
doi:10.3390/antibiotics12050919 .

Marković, Zoran M., Mišović, Aleksandra, Zmejkoski, Danica, Zdravković, Nemanja M., Kovač, Janez, Bajuk-Bogdanović, Danica, Milivojević, Dušan, Mojsin, Marija, Stevanović, Milena, Pavlović, Vladimir B., Todorović-Marković, Biljana, "Employing Gamma-Ray-Modified Carbon Quantum Dots to Combat a Wide Range of Bacteria" in Antibiotics, 12, no. 5 (2023):919,
https://doi.org/10.3390/antibiotics12050919 . .

TY  - JOUR
AU  - Maletić, Marina
AU  - Kalijadis, Ana
AU  - Lazović, Vladimir
AU  - Trifunović, Snežana
AU  - Babić, Biljana M.
AU  - Dapčević, Aleksandra
AU  - Kovač, Janez
AU  - Vukčević, Marija
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10693
AB  - 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
VL  - 88
IS  - 2
SP  - 183
EP  - 197
DO  - 10.2298/JSC220608079M
ER  - 

@article{
author = "Maletić, Marina and Kalijadis, Ana and Lazović, Vladimir and Trifunović, Snežana and Babić, Biljana M. and Dapčević, Aleksandra and Kovač, Janez and Vukčević, Marija",
year = "2023",
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",
volume = "88",
number = "2",
pages = "183-197",
doi = "10.2298/JSC220608079M"
}

Maletić, M., Kalijadis, A., Lazović, V., Trifunović, S., Babić, B. M., Dapčević, A., Kovač, J.,& Vukčević, 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 M, Kalijadis A, Lazović V, Trifunović S, Babić BM, Dapčević A, Kovač J, Vukčević M. 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, Kalijadis, Ana, Lazović, Vladimir, Trifunović, Snežana, Babić, Biljana M., Dapčević, Aleksandra, Kovač, Janez, Vukčević, Marija, "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  - Ho, Hsin-Chia
AU  - Smiljanić, Milutin
AU  - Jovanović, Zoran M.
AU  - Čekada, Miha
AU  - Kovač, Janez
AU  - Koster, Gertjan
AU  - Hlinka, Jiří
AU  - Hodnik, Nejc
AU  - Spreitzer, Matjaž
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11587
AB  - Development of a robust photocathode using lowcost and high-performing materials, e.g., p-Si, to produce clean fuel hydrogen has remained challenging since the semiconductor substrate is easily susceptible to (photo)corrosion under photoelectrochemical (PEC) operational conditions. A protective layer over the substrate to simultaneously provide corrosion resistance and maintain efficient charge transfer across the device is therefore needed. To this end, in the present work, we utilized pulsed laser deposition (PLD) to prepare a high-quality SrTiO3 (STO) layer to passivate the p-Si substrate using a buffer layer of reduced graphene oxide (rGO). Specifically, a very thin (3.9 nm ∼10 unit cells) STO layer epitaxially overgrown on rGO-buffered Si showed the highest onset potential (0.326 V vs RHE) in comparison to the counterparts with thicker and/or nonepitaxial STO. The photovoltage, flat-band potential, and electrochemical impedance spectroscopy measurements revealed that the epitaxial photocathode was more beneficial for charge separation, charge transfer, and targeted redox reaction than the nonepitaxial one. The STO/rGO/Si with a smooth and highly epitaxial STO layer outperforming the directly contacted STO/Si with a textured and polycrystalline STO layer showed the importance of having a well-defined passivation layer. In addition, the numerous pinholes formed in the directly contacted STO/Si led to the rapid degradation of the photocathode during the PEC measurements. The stability tests demonstrated the soundness of the epitaxial STO layer in passivating Si against corrosion. This study provided a facile approach for preparing a robust protection layer over a photoelectrode substrate in realizing an efficient and, at the same time, durable PEC device.
T2  - ACS Applied Materials & Interfaces
T1  - Robust SrTiO3 Passivation of Silicon Photocathode by Reduced Graphene Oxide for Solar Water Splitting
VL  - 15
IS  - 37
SP  - 44482
EP  - 44492
DO  - 10.1021/acsami.3c07747
ER  - 

@article{
author = "Ho, Hsin-Chia and Smiljanić, Milutin and Jovanović, Zoran M. and Čekada, Miha and Kovač, Janez and Koster, Gertjan and Hlinka, Jiří and Hodnik, Nejc and Spreitzer, Matjaž",
year = "2023",
abstract = "Development of a robust photocathode using lowcost and high-performing materials, e.g., p-Si, to produce clean fuel hydrogen has remained challenging since the semiconductor substrate is easily susceptible to (photo)corrosion under photoelectrochemical (PEC) operational conditions. A protective layer over the substrate to simultaneously provide corrosion resistance and maintain efficient charge transfer across the device is therefore needed. To this end, in the present work, we utilized pulsed laser deposition (PLD) to prepare a high-quality SrTiO3 (STO) layer to passivate the p-Si substrate using a buffer layer of reduced graphene oxide (rGO). Specifically, a very thin (3.9 nm ∼10 unit cells) STO layer epitaxially overgrown on rGO-buffered Si showed the highest onset potential (0.326 V vs RHE) in comparison to the counterparts with thicker and/or nonepitaxial STO. The photovoltage, flat-band potential, and electrochemical impedance spectroscopy measurements revealed that the epitaxial photocathode was more beneficial for charge separation, charge transfer, and targeted redox reaction than the nonepitaxial one. The STO/rGO/Si with a smooth and highly epitaxial STO layer outperforming the directly contacted STO/Si with a textured and polycrystalline STO layer showed the importance of having a well-defined passivation layer. In addition, the numerous pinholes formed in the directly contacted STO/Si led to the rapid degradation of the photocathode during the PEC measurements. The stability tests demonstrated the soundness of the epitaxial STO layer in passivating Si against corrosion. This study provided a facile approach for preparing a robust protection layer over a photoelectrode substrate in realizing an efficient and, at the same time, durable PEC device.",
journal = "ACS Applied Materials & Interfaces",
title = "Robust SrTiO3 Passivation of Silicon Photocathode by Reduced Graphene Oxide for Solar Water Splitting",
volume = "15",
number = "37",
pages = "44482-44492",
doi = "10.1021/acsami.3c07747"
}

Ho, H., Smiljanić, M., Jovanović, Z. M., Čekada, M., Kovač, J., Koster, G., Hlinka, J., Hodnik, N.,& Spreitzer, M.. (2023). Robust SrTiO3 Passivation of Silicon Photocathode by Reduced Graphene Oxide for Solar Water Splitting. in ACS Applied Materials & Interfaces, 15(37), 44482-44492.
https://doi.org/10.1021/acsami.3c07747

Ho H, Smiljanić M, Jovanović ZM, Čekada M, Kovač J, Koster G, Hlinka J, Hodnik N, Spreitzer M. Robust SrTiO3 Passivation of Silicon Photocathode by Reduced Graphene Oxide for Solar Water Splitting. in ACS Applied Materials & Interfaces. 2023;15(37):44482-44492.
doi:10.1021/acsami.3c07747 .

Ho, Hsin-Chia, Smiljanić, Milutin, Jovanović, Zoran M., Čekada, Miha, Kovač, Janez, Koster, Gertjan, Hlinka, Jiří, Hodnik, Nejc, Spreitzer, Matjaž, "Robust SrTiO3 Passivation of Silicon Photocathode by Reduced Graphene Oxide for Solar Water Splitting" in ACS Applied Materials & Interfaces, 15, no. 37 (2023):44482-44492,
https://doi.org/10.1021/acsami.3c07747 . .

TY  - CONF
AU  - Petković, Darija
AU  - Chia-Ho, Hsin
AU  - Trstenjak, Urška
AU  - Kovač, Janez
AU  - Vengust, Damjan
AU  - Jovanović, Zoran
AU  - Spreitzer, Matjaž
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12333
AB  - Epitaxial films of metal oxides deposited on silicon substrates represent a new type of material that could be used as protective (or electroactive) layer in the photoelectrochemical water splitting. To understand the influence of crystalline and interfacial properties of oxide layer on the water splitting process a ~10 nm strontium titanate (STO) films have been grown using the PLD method on bare and reduced graphene oxide (rGO) buffered silicon substrate. Our approach relied on the oxide-silicon integration using combination of SrO-assisted deoxidation and controllable coverage of silicon surface with a mono- to threelayer of spin-coated GO. The STO films have been grown at 515 and 700 °C and various experimental techniques were used to examine the surface and crystalline properties of grown films (reflection high energy electron diffraction, atomic force microscopy, scanning electron microscopy, X-ray diffraction, X-ray reflectivity and X-ray photoelectron spectroscopy). The results show that the best the crystallinity of the STO thin films was obtained on rGO/SrO deoxidized silicon surface at 515 °C. Future studies will be devoted to electrochemical characterization of the grown films, that will help to establish clearer link on how the interface and crystalline parameters affect the water splitting process.
PB  - EU COST Action OPERA
C3  - Workshop “Application-oriented material development” : Book of abstracts
T1  - PLD growth of strontium titanate thin films on silicon substrate for photoelectrochemical water-splitting
UR  - https://hdl.handle.net/21.15107/rcub_vinar_12333
ER  - 

@conference{
author = "Petković, Darija and Chia-Ho, Hsin and Trstenjak, Urška and Kovač, Janez and Vengust, Damjan and Jovanović, Zoran and Spreitzer, Matjaž",
year = "2023",
abstract = "Epitaxial films of metal oxides deposited on silicon substrates represent a new type of material that could be used as protective (or electroactive) layer in the photoelectrochemical water splitting. To understand the influence of crystalline and interfacial properties of oxide layer on the water splitting process a ~10 nm strontium titanate (STO) films have been grown using the PLD method on bare and reduced graphene oxide (rGO) buffered silicon substrate. Our approach relied on the oxide-silicon integration using combination of SrO-assisted deoxidation and controllable coverage of silicon surface with a mono- to threelayer of spin-coated GO. The STO films have been grown at 515 and 700 °C and various experimental techniques were used to examine the surface and crystalline properties of grown films (reflection high energy electron diffraction, atomic force microscopy, scanning electron microscopy, X-ray diffraction, X-ray reflectivity and X-ray photoelectron spectroscopy). The results show that the best the crystallinity of the STO thin films was obtained on rGO/SrO deoxidized silicon surface at 515 °C. Future studies will be devoted to electrochemical characterization of the grown films, that will help to establish clearer link on how the interface and crystalline parameters affect the water splitting process.",
publisher = "EU COST Action OPERA",
journal = "Workshop “Application-oriented material development” : Book of abstracts",
title = "PLD growth of strontium titanate thin films on silicon substrate for photoelectrochemical water-splitting",
url = "https://hdl.handle.net/21.15107/rcub_vinar_12333"
}

Petković, D., Chia-Ho, H., Trstenjak, U., Kovač, J., Vengust, D., Jovanović, Z.,& Spreitzer, M.. (2023). PLD growth of strontium titanate thin films on silicon substrate for photoelectrochemical water-splitting. in Workshop “Application-oriented material development” : Book of abstracts
EU COST Action OPERA..
https://hdl.handle.net/21.15107/rcub_vinar_12333

Petković D, Chia-Ho H, Trstenjak U, Kovač J, Vengust D, Jovanović Z, Spreitzer M. PLD growth of strontium titanate thin films on silicon substrate for photoelectrochemical water-splitting. in Workshop “Application-oriented material development” : Book of abstracts. 2023;.
https://hdl.handle.net/21.15107/rcub_vinar_12333 .

Petković, Darija, Chia-Ho, Hsin, Trstenjak, Urška, Kovač, Janez, Vengust, Damjan, Jovanović, Zoran, Spreitzer, Matjaž, "PLD growth of strontium titanate thin films on silicon substrate for photoelectrochemical water-splitting" in Workshop “Application-oriented material development” : Book of abstracts (2023),
https://hdl.handle.net/21.15107/rcub_vinar_12333 .

TY  - JOUR
AU  - Krstić, Aleksandar D.
AU  - Lolić, Aleksandar
AU  - Mirković, Miljana M.
AU  - Kovač, Janez
AU  - Minović-Arsić, Tamara
AU  - Babić, Biljana
AU  - Kalijadis, Ana
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10552
AB  - In this study carbon cryogel, cryogel doped with nitrogen, and both nitrogen and sulfur co-doped carbon cryogels (nominal concentration of nitrogen was in the range 2–10 wt%) were synthesized and used as an adsorbent for the removal of carbamazepine, naproxen, diazepam and diclofenac from water. A batch adsorption kinetics study was performed by determination of contact time influence, the effect of pH, and adsorption isotherms. Structural and morphological analysis showed that there are no changes in turbostratic carbon structure induced by doping/co-doping, but noticeable morphology changes were observed. The presence of both nitrogen and nitrogen/sulfur were confirmed and results showed low content on the surface, especially for sulfur. Obtained high values of the specific surface area for co-doped samples (up to 1530 m2/g) can be caused by sulfur atoms burning or leaving the material during carbonization. The results of the adsorption kinetics study showed that the adsorption of all pharmaceuticals on all tested samples followed the pseudo-second-order kinetic model. The maximum adsorption capacity obtained from the Langmuir isotherm model is higher for doped (91.28–168.92 mg/g) and co-doped (152.97–488.06 mg/g) samples than for pristine sample (59.75–266.28 mg/g). Calculated adsorption energy values from the Dubinin-Radushkevich model indicate that the possible mechanism was physisorption. Desorption tests that were carried out showed satisfactory reusability for all samples. The favorable adsorption characteristics for the co-doped sample with a higher nominal concentration of nitrogen and sulfur qualifies as a potentially good adsorbent for the removal of pharmaceuticals from water.
T2  - Journal of Environmental Chemical Engineering
T1  - Synthesis of nitrogen doped and nitrogen and sulfur co-doped carbon cryogels and their application for pharmaceuticals removal from water
VL  - 10
IS  - 6
SP  - 108998
DO  - 10.1016/j.jece.2022.108998
ER  - 

@article{
author = "Krstić, Aleksandar D. and Lolić, Aleksandar and Mirković, Miljana M. and Kovač, Janez and Minović-Arsić, Tamara and Babić, Biljana and Kalijadis, Ana",
year = "2022",
abstract = "In this study carbon cryogel, cryogel doped with nitrogen, and both nitrogen and sulfur co-doped carbon cryogels (nominal concentration of nitrogen was in the range 2–10 wt%) were synthesized and used as an adsorbent for the removal of carbamazepine, naproxen, diazepam and diclofenac from water. A batch adsorption kinetics study was performed by determination of contact time influence, the effect of pH, and adsorption isotherms. Structural and morphological analysis showed that there are no changes in turbostratic carbon structure induced by doping/co-doping, but noticeable morphology changes were observed. The presence of both nitrogen and nitrogen/sulfur were confirmed and results showed low content on the surface, especially for sulfur. Obtained high values of the specific surface area for co-doped samples (up to 1530 m2/g) can be caused by sulfur atoms burning or leaving the material during carbonization. The results of the adsorption kinetics study showed that the adsorption of all pharmaceuticals on all tested samples followed the pseudo-second-order kinetic model. The maximum adsorption capacity obtained from the Langmuir isotherm model is higher for doped (91.28–168.92 mg/g) and co-doped (152.97–488.06 mg/g) samples than for pristine sample (59.75–266.28 mg/g). Calculated adsorption energy values from the Dubinin-Radushkevich model indicate that the possible mechanism was physisorption. Desorption tests that were carried out showed satisfactory reusability for all samples. The favorable adsorption characteristics for the co-doped sample with a higher nominal concentration of nitrogen and sulfur qualifies as a potentially good adsorbent for the removal of pharmaceuticals from water.",
journal = "Journal of Environmental Chemical Engineering",
title = "Synthesis of nitrogen doped and nitrogen and sulfur co-doped carbon cryogels and their application for pharmaceuticals removal from water",
volume = "10",
number = "6",
pages = "108998",
doi = "10.1016/j.jece.2022.108998"
}

Krstić, A. D., Lolić, A., Mirković, M. M., Kovač, J., Minović-Arsić, T., Babić, B.,& Kalijadis, A.. (2022). Synthesis of nitrogen doped and nitrogen and sulfur co-doped carbon cryogels and their application for pharmaceuticals removal from water. in Journal of Environmental Chemical Engineering, 10(6), 108998.
https://doi.org/10.1016/j.jece.2022.108998

Krstić AD, Lolić A, Mirković MM, Kovač J, Minović-Arsić T, Babić B, Kalijadis A. Synthesis of nitrogen doped and nitrogen and sulfur co-doped carbon cryogels and their application for pharmaceuticals removal from water. in Journal of Environmental Chemical Engineering. 2022;10(6):108998.
doi:10.1016/j.jece.2022.108998 .

Krstić, Aleksandar D., Lolić, Aleksandar, Mirković, Miljana M., Kovač, Janez, Minović-Arsić, Tamara, Babić, Biljana, Kalijadis, Ana, "Synthesis of nitrogen doped and nitrogen and sulfur co-doped carbon cryogels and their application for pharmaceuticals removal from water" in Journal of Environmental Chemical Engineering, 10, no. 6 (2022):108998,
https://doi.org/10.1016/j.jece.2022.108998 . .

TY  - JOUR
AU  - Janošević-Ležaić, Aleksandra
AU  - Bajuk-Bogdanović, Danica V.
AU  - Krstić, Jugoslav B.
AU  - Jovanović, Zoran
AU  - Mravik, Željko
AU  - Kovač, Janez
AU  - Gavrilov, Nemanja
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10213
AB  - Transformation of tannic acid (TA), a cheap, abundant and environmentally friendly (by)product, upon carbonization at various temperatures was examined as it is extensively being used in energy storing devices. In addition of reviling what is happening with TA upon carbonization, a step further has been taken to scrutinize the role of carbonized TA (CTA) playing in energy storage composites. Increasing the carbonization temperature from 500 ◦C to 800 ◦C led to a nine orders of magnitude increase in conductivity, from 9⋅10–9 S cm
T2  - Fuel
T1  - What role does carbonized tannic acid play in energy storage composites?
VL  - 312
DO  - 10.1016/j.fuel.2021.122930
ER  - 

@article{
author = "Janošević-Ležaić, Aleksandra and Bajuk-Bogdanović, Danica V. and Krstić, Jugoslav B. and Jovanović, Zoran and Mravik, Željko and Kovač, Janez and Gavrilov, Nemanja",
year = "2022",
abstract = "Transformation of tannic acid (TA), a cheap, abundant and environmentally friendly (by)product, upon carbonization at various temperatures was examined as it is extensively being used in energy storing devices. In addition of reviling what is happening with TA upon carbonization, a step further has been taken to scrutinize the role of carbonized TA (CTA) playing in energy storage composites. Increasing the carbonization temperature from 500 ◦C to 800 ◦C led to a nine orders of magnitude increase in conductivity, from 9⋅10–9 S cm",
journal = "Fuel",
title = "What role does carbonized tannic acid play in energy storage composites?",
volume = "312",
doi = "10.1016/j.fuel.2021.122930"
}

Janošević-Ležaić, A., Bajuk-Bogdanović, D. V., Krstić, J. B., Jovanović, Z., Mravik, Ž., Kovač, J.,& Gavrilov, N.. (2022). What role does carbonized tannic acid play in energy storage composites?. in Fuel, 312.
https://doi.org/10.1016/j.fuel.2021.122930

Janošević-Ležaić A, Bajuk-Bogdanović DV, Krstić JB, Jovanović Z, Mravik Ž, Kovač J, Gavrilov N. What role does carbonized tannic acid play in energy storage composites?. in Fuel. 2022;312.
doi:10.1016/j.fuel.2021.122930 .

Janošević-Ležaić, Aleksandra, Bajuk-Bogdanović, Danica V., Krstić, Jugoslav B., Jovanović, Zoran, Mravik, Željko, Kovač, Janez, Gavrilov, Nemanja, "What role does carbonized tannic acid play in energy storage composites?" in Fuel, 312 (2022),
https://doi.org/10.1016/j.fuel.2021.122930 . .

TY  - JOUR
AU  - Pjević, Dejan J.
AU  - Savić, Tatjana D.
AU  - Petrović, Suzana
AU  - Peruško, Davor
AU  - Čomor, Mirjana
AU  - Kovač, Janez
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9841
AB  - The influence of deposition and annealing parameters on optical, structural and photocatalytic properties of N-doped titanium-dioxide (TiO2) thin films have been studied. Anatase and anatase-rutile crystalline phase mixture TiO2 thin films were obtained depending on the reactive direct current (DC) sputtering and annealing conditions. Deposition in the nitrogen atmosphere produced N-doped TiO2 thin films with energy gap values shifted towards visible region in comparison with thin TiO2 films deposited without nitrogen in the atmosphere. The role of substitutional and interstitial nitrogen atoms incorporated in obtained crystalline structures during the deposition was shown important and was reflected in the efficiency of photocatalysis. It was found that thin TiO2 films with more substitutional incorporated nitrogen exhibits better photocatalytic properties. These results could be of importance towards achieving controlled synthesis of N-doped TiO2 thin films with desired structural and optical properties, especially with improved photo-activity in the visible part of the solar spectrum.
T2  - ECS Journal of Solid State Science and Technology
T1  - Influence of Nitrogen Incorporation Sites on Structural and Optical Properties of Sputtered TiO2-N Thin Films with Improved Visible Light Activity
VL  - 10
IS  - 5
SP  - 053002
DO  - 10.1149/2162-8777/abffb2
ER  - 

@article{
author = "Pjević, Dejan J. and Savić, Tatjana D. and Petrović, Suzana and Peruško, Davor and Čomor, Mirjana and Kovač, Janez",
year = "2021",
abstract = "The influence of deposition and annealing parameters on optical, structural and photocatalytic properties of N-doped titanium-dioxide (TiO2) thin films have been studied. Anatase and anatase-rutile crystalline phase mixture TiO2 thin films were obtained depending on the reactive direct current (DC) sputtering and annealing conditions. Deposition in the nitrogen atmosphere produced N-doped TiO2 thin films with energy gap values shifted towards visible region in comparison with thin TiO2 films deposited without nitrogen in the atmosphere. The role of substitutional and interstitial nitrogen atoms incorporated in obtained crystalline structures during the deposition was shown important and was reflected in the efficiency of photocatalysis. It was found that thin TiO2 films with more substitutional incorporated nitrogen exhibits better photocatalytic properties. These results could be of importance towards achieving controlled synthesis of N-doped TiO2 thin films with desired structural and optical properties, especially with improved photo-activity in the visible part of the solar spectrum.",
journal = "ECS Journal of Solid State Science and Technology",
title = "Influence of Nitrogen Incorporation Sites on Structural and Optical Properties of Sputtered TiO2-N Thin Films with Improved Visible Light Activity",
volume = "10",
number = "5",
pages = "053002",
doi = "10.1149/2162-8777/abffb2"
}

Pjević, D. J., Savić, T. D., Petrović, S., Peruško, D., Čomor, M.,& Kovač, J.. (2021). Influence of Nitrogen Incorporation Sites on Structural and Optical Properties of Sputtered TiO2-N Thin Films with Improved Visible Light Activity. in ECS Journal of Solid State Science and Technology, 10(5), 053002.
https://doi.org/10.1149/2162-8777/abffb2

Pjević DJ, Savić TD, Petrović S, Peruško D, Čomor M, Kovač J. Influence of Nitrogen Incorporation Sites on Structural and Optical Properties of Sputtered TiO2-N Thin Films with Improved Visible Light Activity. in ECS Journal of Solid State Science and Technology. 2021;10(5):053002.
doi:10.1149/2162-8777/abffb2 .

Pjević, Dejan J., Savić, Tatjana D., Petrović, Suzana, Peruško, Davor, Čomor, Mirjana, Kovač, Janez, "Influence of Nitrogen Incorporation Sites on Structural and Optical Properties of Sputtered TiO2-N Thin Films with Improved Visible Light Activity" in ECS Journal of Solid State Science and Technology, 10, no. 5 (2021):053002,
https://doi.org/10.1149/2162-8777/abffb2 . .

TY  - JOUR
AU  - Mravik, Željko
AU  - Bajuk-Bogdanović, Danica V.
AU  - Mraković, Ana Đ.
AU  - Vukosavljević, Ljubiša
AU  - Trajić, Ivan
AU  - Kovač, Janez
AU  - Peruško, Davor
AU  - Gavrilov, Nemanja
AU  - Jovanović, Zoran M.
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9150
AB  - In recent years polyoxometalates (POMs) have attracted significant research interest due to versatile properties. These properties are determined by the size, structure and elemental composition of POMs and hence play an important role in their application. In the present study, the ion beam irradiation (10 keV C+ ions, 5 × 1014–2.5 × 1015 ions/cm2) has been utilized for modification of physicochemical properties of 120 nm-thick layer of 12-tungstophosphoric acid (WPA). Scanning electron microscopy analysis of irradiated films showed change of morphology i.e. an increase of WPA grain size with irradiation and coalescence of grains at the highest fluence. This was accompanied by structural changes. Attenuated total reflectance Fourier transform infrared analysis revealed that vibration bands of Keggin anion became less pronounced as fluence increased, while Raman spectra appeared as strongly modified. The effect of irradiation with 1.25 × 1015 ions/cm2 on the structure of WPA was similar to the effect of thermal treatment at 600 °C. Irradiation of WPA led to decrease of the band gap (from 4.07 to 3.92 eV), which was correlated to transformation Keggin anions into a network of WO6 octahedra and PO4 tetrahedra. This is in line with increased number of W=Od bonds observed by UV–Visible diffuse reflectance spectroscopy. Beside transformation to bronzes a reduction of WPA was observed by X-ray Photoelectron Spectroscopy (shift to lower binding energy) and Raman methods, whereas the Raman spectra of irradiated samples were similar to heteropoly blue. The electrochemical properties of irradiated WPA were also assessed. Cyclic voltammetry measurements showed that at up to 1.25 × 1015 ions/cm2 lithiation capacity of WPA increases and activity for hydrogen evolution reaction (HER) improves. The highest fluence caused interconnection of WO6 octahedra, closing of lithiation pathways and decrease in the number of active sites for HER. Our results provide a novel insight into the effects of ion beam irradiation on WPA and demonstrate high potential for tuning of physicochemical properties of POMs that are relevant in wide range of applications. © 2021 Elsevier Ltd
T2  - Radiation Physics and Chemistry
T1  - Structural and electrochemical properties of carbon ion beam irradiated 12-tungstophosphoric acid
VL  - 183
SP  - 109422
DO  - 10.1016/j.radphyschem.2021.109422
ER  - 

@article{
author = "Mravik, Željko and Bajuk-Bogdanović, Danica V. and Mraković, Ana Đ. and Vukosavljević, Ljubiša and Trajić, Ivan and Kovač, Janez and Peruško, Davor and Gavrilov, Nemanja and Jovanović, Zoran M.",
year = "2021",
abstract = "In recent years polyoxometalates (POMs) have attracted significant research interest due to versatile properties. These properties are determined by the size, structure and elemental composition of POMs and hence play an important role in their application. In the present study, the ion beam irradiation (10 keV C+ ions, 5 × 1014–2.5 × 1015 ions/cm2) has been utilized for modification of physicochemical properties of 120 nm-thick layer of 12-tungstophosphoric acid (WPA). Scanning electron microscopy analysis of irradiated films showed change of morphology i.e. an increase of WPA grain size with irradiation and coalescence of grains at the highest fluence. This was accompanied by structural changes. Attenuated total reflectance Fourier transform infrared analysis revealed that vibration bands of Keggin anion became less pronounced as fluence increased, while Raman spectra appeared as strongly modified. The effect of irradiation with 1.25 × 1015 ions/cm2 on the structure of WPA was similar to the effect of thermal treatment at 600 °C. Irradiation of WPA led to decrease of the band gap (from 4.07 to 3.92 eV), which was correlated to transformation Keggin anions into a network of WO6 octahedra and PO4 tetrahedra. This is in line with increased number of W=Od bonds observed by UV–Visible diffuse reflectance spectroscopy. Beside transformation to bronzes a reduction of WPA was observed by X-ray Photoelectron Spectroscopy (shift to lower binding energy) and Raman methods, whereas the Raman spectra of irradiated samples were similar to heteropoly blue. The electrochemical properties of irradiated WPA were also assessed. Cyclic voltammetry measurements showed that at up to 1.25 × 1015 ions/cm2 lithiation capacity of WPA increases and activity for hydrogen evolution reaction (HER) improves. The highest fluence caused interconnection of WO6 octahedra, closing of lithiation pathways and decrease in the number of active sites for HER. Our results provide a novel insight into the effects of ion beam irradiation on WPA and demonstrate high potential for tuning of physicochemical properties of POMs that are relevant in wide range of applications. © 2021 Elsevier Ltd",
journal = "Radiation Physics and Chemistry",
title = "Structural and electrochemical properties of carbon ion beam irradiated 12-tungstophosphoric acid",
volume = "183",
pages = "109422",
doi = "10.1016/j.radphyschem.2021.109422"
}

Mravik, Ž., Bajuk-Bogdanović, D. V., Mraković, A. Đ., Vukosavljević, L., Trajić, I., Kovač, J., Peruško, D., Gavrilov, N.,& Jovanović, Z. M.. (2021). Structural and electrochemical properties of carbon ion beam irradiated 12-tungstophosphoric acid. in Radiation Physics and Chemistry, 183, 109422.
https://doi.org/10.1016/j.radphyschem.2021.109422

Mravik Ž, Bajuk-Bogdanović DV, Mraković AĐ, Vukosavljević L, Trajić I, Kovač J, Peruško D, Gavrilov N, Jovanović ZM. Structural and electrochemical properties of carbon ion beam irradiated 12-tungstophosphoric acid. in Radiation Physics and Chemistry. 2021;183:109422.
doi:10.1016/j.radphyschem.2021.109422 .

Mravik, Željko, Bajuk-Bogdanović, Danica V., Mraković, Ana Đ., Vukosavljević, Ljubiša, Trajić, Ivan, Kovač, Janez, Peruško, Davor, Gavrilov, Nemanja, Jovanović, Zoran M., "Structural and electrochemical properties of carbon ion beam irradiated 12-tungstophosphoric acid" in Radiation Physics and Chemistry, 183 (2021):109422,
https://doi.org/10.1016/j.radphyschem.2021.109422 . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Peruško, Davor
AU  - Mimidis, Alexandros
AU  - Kavatzikidou, Paraskevi
AU  - Kovač, Janez
AU  - Ranella, Anthi
AU  - Novaković, Mirjana M.
AU  - Popović, Maja
AU  - Stratakis, Emmanuel
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9785
AB  - Ultrafast laser processing with the formation of periodic surface nanostructures on the 15×(Ti/Zr)/Si multilayers is studied in order to the improve cell response. A novel nanocomposite structure in the form of 15x(Ti/Zr)/Si multilayer thin films, with satisfying mechanical properties and moderate biocompatibility, was deposited by ion sputtering on an Si substrate. The multilayer 15×(Ti/Zr)/Si thin films were modified by femtosecond laser pulses in air to induce the following modifications: (i) mixing of components inside of the multilayer structures, (ii) the formation of an ultrathin oxide layer at the surfaces, and (iii) surface nano-texturing with the creation of laser-induced periodic surface structure (LIPSS). The focus of this study was an examination of the novel Ti/Zr multilayer thin films in order to create a surface texture with suitable composition and structure for cell integration. Using the SEM and confocal microscopies of the laser-modified Ti/Zr surfaces with seeded cell culture (NIH 3T3 fibroblasts), it was found that cell adhesion and growth depend on the surface composition and morphological patterns. These results indicated a good proliferation of cells after two and four days with some tendency of the cell orientation along the LIPSSs. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
T2  - Nanomaterials
T1  - Response of NIH 3T3 fibroblast cells on laser-induced periodic surface structures on a 15×(Ti/Zr)/Si multilayer system
VL  - 10
IS  - 12
SP  - 1
EP  - 14
DO  - 10.3390/nano10122531
ER  - 

@article{
author = "Petrović, Suzana and Peruško, Davor and Mimidis, Alexandros and Kavatzikidou, Paraskevi and Kovač, Janez and Ranella, Anthi and Novaković, Mirjana M. and Popović, Maja and Stratakis, Emmanuel",
year = "2020",
abstract = "Ultrafast laser processing with the formation of periodic surface nanostructures on the 15×(Ti/Zr)/Si multilayers is studied in order to the improve cell response. A novel nanocomposite structure in the form of 15x(Ti/Zr)/Si multilayer thin films, with satisfying mechanical properties and moderate biocompatibility, was deposited by ion sputtering on an Si substrate. The multilayer 15×(Ti/Zr)/Si thin films were modified by femtosecond laser pulses in air to induce the following modifications: (i) mixing of components inside of the multilayer structures, (ii) the formation of an ultrathin oxide layer at the surfaces, and (iii) surface nano-texturing with the creation of laser-induced periodic surface structure (LIPSS). The focus of this study was an examination of the novel Ti/Zr multilayer thin films in order to create a surface texture with suitable composition and structure for cell integration. Using the SEM and confocal microscopies of the laser-modified Ti/Zr surfaces with seeded cell culture (NIH 3T3 fibroblasts), it was found that cell adhesion and growth depend on the surface composition and morphological patterns. These results indicated a good proliferation of cells after two and four days with some tendency of the cell orientation along the LIPSSs. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.",
journal = "Nanomaterials",
title = "Response of NIH 3T3 fibroblast cells on laser-induced periodic surface structures on a 15×(Ti/Zr)/Si multilayer system",
volume = "10",
number = "12",
pages = "1-14",
doi = "10.3390/nano10122531"
}

Petrović, S., Peruško, D., Mimidis, A., Kavatzikidou, P., Kovač, J., Ranella, A., Novaković, M. M., Popović, M.,& Stratakis, E.. (2020). Response of NIH 3T3 fibroblast cells on laser-induced periodic surface structures on a 15×(Ti/Zr)/Si multilayer system. in Nanomaterials, 10(12), 1-14.
https://doi.org/10.3390/nano10122531

Petrović S, Peruško D, Mimidis A, Kavatzikidou P, Kovač J, Ranella A, Novaković MM, Popović M, Stratakis E. Response of NIH 3T3 fibroblast cells on laser-induced periodic surface structures on a 15×(Ti/Zr)/Si multilayer system. in Nanomaterials. 2020;10(12):1-14.
doi:10.3390/nano10122531 .

Petrović, Suzana, Peruško, Davor, Mimidis, Alexandros, Kavatzikidou, Paraskevi, Kovač, Janez, Ranella, Anthi, Novaković, Mirjana M., Popović, Maja, Stratakis, Emmanuel, "Response of NIH 3T3 fibroblast cells on laser-induced periodic surface structures on a 15×(Ti/Zr)/Si multilayer system" in Nanomaterials, 10, no. 12 (2020):1-14,
https://doi.org/10.3390/nano10122531 . .

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  - Petrović, Suzana
AU  - Peruško, Davor
AU  - Skoulas, Evangelos
AU  - Kovač, Janez
AU  - Mitrić, Miodrag
AU  - Potočnik, Jelena
AU  - Rakočević, Zlatko Lj.
AU  - Stratakis, Emmanuel
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8816
AB  - The formation of an ordered surface texture with micro and nanometer features on Ti/Zr multilayers is studied for better understanding and improvement of cell integration. Nanocomposite in form 30×(Ti/Zr)/Si thin films was deposited by ion sputtering on Si substrate for biocompatibility investigation. Surface texturing by femtosecond laser processing made it possible to form the laser-induced periodic surface structure (LIPSS) in each laser-written line. At fluence slightly above the ablation threshold, beside the formation of low spatial frequency-LIPSS (LSFL) oriented perpendicular to the direction of the laser polarization, the laser-induced surface oxidation was achieved on the irradiated area. Intermixing between the Ti and Zr layers with the formation of alloy in the sub-surface region was attained during the laser processing. The surface of the Ti/Zr multilayer system with changed composition and topography was used to observe the effect of topography on the survival, adhesion and proliferation of the murine mesenchymal stem cells (MSCs). Confocal and SEM microscopy images showed that cell adhesion and their growth improve on these modified surfaces, with tendency of the cell orientation along of LIPSS in laser-written lines. © 2019 by the authors.
T2  - Coatings
T1  - Laser-assisted surface texturing of Ti/Zr multilayers for mesenchymal stem cell response
VL  - 9
IS  - 12
SP  - 854
DO  - 10.3390/coatings9120854
ER  - 

@article{
author = "Petrović, Suzana and Peruško, Davor and Skoulas, Evangelos and Kovač, Janez and Mitrić, Miodrag and Potočnik, Jelena and Rakočević, Zlatko Lj. and Stratakis, Emmanuel",
year = "2019",
abstract = "The formation of an ordered surface texture with micro and nanometer features on Ti/Zr multilayers is studied for better understanding and improvement of cell integration. Nanocomposite in form 30×(Ti/Zr)/Si thin films was deposited by ion sputtering on Si substrate for biocompatibility investigation. Surface texturing by femtosecond laser processing made it possible to form the laser-induced periodic surface structure (LIPSS) in each laser-written line. At fluence slightly above the ablation threshold, beside the formation of low spatial frequency-LIPSS (LSFL) oriented perpendicular to the direction of the laser polarization, the laser-induced surface oxidation was achieved on the irradiated area. Intermixing between the Ti and Zr layers with the formation of alloy in the sub-surface region was attained during the laser processing. The surface of the Ti/Zr multilayer system with changed composition and topography was used to observe the effect of topography on the survival, adhesion and proliferation of the murine mesenchymal stem cells (MSCs). Confocal and SEM microscopy images showed that cell adhesion and their growth improve on these modified surfaces, with tendency of the cell orientation along of LIPSS in laser-written lines. © 2019 by the authors.",
journal = "Coatings",
title = "Laser-assisted surface texturing of Ti/Zr multilayers for mesenchymal stem cell response",
volume = "9",
number = "12",
pages = "854",
doi = "10.3390/coatings9120854"
}

Petrović, S., Peruško, D., Skoulas, E., Kovač, J., Mitrić, M., Potočnik, J., Rakočević, Z. Lj.,& Stratakis, E.. (2019). Laser-assisted surface texturing of Ti/Zr multilayers for mesenchymal stem cell response. in Coatings, 9(12), 854.
https://doi.org/10.3390/coatings9120854

Petrović S, Peruško D, Skoulas E, Kovač J, Mitrić M, Potočnik J, Rakočević ZL, Stratakis E. Laser-assisted surface texturing of Ti/Zr multilayers for mesenchymal stem cell response. in Coatings. 2019;9(12):854.
doi:10.3390/coatings9120854 .

Petrović, Suzana, Peruško, Davor, Skoulas, Evangelos, Kovač, Janez, Mitrić, Miodrag, Potočnik, Jelena, Rakočević, Zlatko Lj., Stratakis, Emmanuel, "Laser-assisted surface texturing of Ti/Zr multilayers for mesenchymal stem cell response" in Coatings, 9, no. 12 (2019):854,
https://doi.org/10.3390/coatings9120854 . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Gaković, Biljana M.
AU  - Panjan, Peter
AU  - Kovač, Janez
AU  - Lazović, Vladimir M.
AU  - Ristoscu, Carmen
AU  - Negut, Irina
AU  - Mihailescu, Ion N.
PY  - 2018
UR  - http://link.springer.com/10.1007/s11082-018-1475-3
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7686
AB  - The oxidation behaviour and morphological modification of CrN/(Cr,V)N coatings on Si wafers were studied after UV nanosecond laser (wavelength 248 nm, pulse duration 25 ns) processing in ambient air. The evolution of the surface composition and microstructure with the number of accumulated/subsequent pulses was systematically analysed depending on the initial content of vanadium in the as-deposited coatings. Irradiation of CrN/(Cr,V)N coatings with different content of vanadium was carried out at a fluence of 0.17 J cm−2with different number of pulses. The concentration of metallic components was fairly homogeneous distributed throughout the sample. However, on surface and in sub-surface regions the contents of Cr and V are diminished due to laser-induced oxidation. The composition and thickness of forming oxides mixture, Cr2O3and V2O5, are depending on the number of applied laser pulses and the initial vanadium content. The asymmetric progress of surface morphology is characterized by the formation of grainy structures at peripheries and the appearance of cracks and irregular closed shapes in the centre of the irradiation area.
T2  - Optical and Quantum Electronics
T1  - Oxidation behaviour of composite CrN/(Cr,V)N coatings with different contents of vanadium induced by UV nanosecond laser pulses
VL  - 50
IS  - 5
SP  - 208
DO  - 10.1007/s11082-018-1475-3
ER  - 

@article{
author = "Petrović, Suzana and Gaković, Biljana M. and Panjan, Peter and Kovač, Janez and Lazović, Vladimir M. and Ristoscu, Carmen and Negut, Irina and Mihailescu, Ion N.",
year = "2018",
abstract = "The oxidation behaviour and morphological modification of CrN/(Cr,V)N coatings on Si wafers were studied after UV nanosecond laser (wavelength 248 nm, pulse duration 25 ns) processing in ambient air. The evolution of the surface composition and microstructure with the number of accumulated/subsequent pulses was systematically analysed depending on the initial content of vanadium in the as-deposited coatings. Irradiation of CrN/(Cr,V)N coatings with different content of vanadium was carried out at a fluence of 0.17 J cm−2with different number of pulses. The concentration of metallic components was fairly homogeneous distributed throughout the sample. However, on surface and in sub-surface regions the contents of Cr and V are diminished due to laser-induced oxidation. The composition and thickness of forming oxides mixture, Cr2O3and V2O5, are depending on the number of applied laser pulses and the initial vanadium content. The asymmetric progress of surface morphology is characterized by the formation of grainy structures at peripheries and the appearance of cracks and irregular closed shapes in the centre of the irradiation area.",
journal = "Optical and Quantum Electronics",
title = "Oxidation behaviour of composite CrN/(Cr,V)N coatings with different contents of vanadium induced by UV nanosecond laser pulses",
volume = "50",
number = "5",
pages = "208",
doi = "10.1007/s11082-018-1475-3"
}

Petrović, S., Gaković, B. M., Panjan, P., Kovač, J., Lazović, V. M., Ristoscu, C., Negut, I.,& Mihailescu, I. N.. (2018). Oxidation behaviour of composite CrN/(Cr,V)N coatings with different contents of vanadium induced by UV nanosecond laser pulses. in Optical and Quantum Electronics, 50(5), 208.
https://doi.org/10.1007/s11082-018-1475-3

Petrović S, Gaković BM, Panjan P, Kovač J, Lazović VM, Ristoscu C, Negut I, Mihailescu IN. Oxidation behaviour of composite CrN/(Cr,V)N coatings with different contents of vanadium induced by UV nanosecond laser pulses. in Optical and Quantum Electronics. 2018;50(5):208.
doi:10.1007/s11082-018-1475-3 .

Petrović, Suzana, Gaković, Biljana M., Panjan, Peter, Kovač, Janez, Lazović, Vladimir M., Ristoscu, Carmen, Negut, Irina, Mihailescu, Ion N., "Oxidation behaviour of composite CrN/(Cr,V)N coatings with different contents of vanadium induced by UV nanosecond laser pulses" in Optical and Quantum Electronics, 50, no. 5 (2018):208,
https://doi.org/10.1007/s11082-018-1475-3 . .

TY  - JOUR
AU  - Obradović, Marko O.
AU  - Kovač, Janez
AU  - Petrović, Suzana
AU  - Lazović, Vladimir M.
AU  - Salatić, Branislav
AU  - Ciganović, Jovan
AU  - Pjević, Dejan J.
AU  - Milosavljević, Momir
AU  - Peruško, Davor
PY  - 2018
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7721
AB  - The possibility of interlayer mixing in a Ti/Ta multilayer system, induced by laser irradiation, was the main purpose of these experiments. Ti/Ta multilayer system, consisting of ten alternating Ti and Ta thin films and covered by slightly thicker Ti layer, was deposited on Si (100) wafers to a total thickness of 205 nm. Laser irradiation was performed in air by picoseconds Nd:YAG laser pulses in defocused regime with fluences of 0.057 and 0.11 J cm−2. Laser beam was scanned over the 5 × 5 mm surface area with different steps along y-axes. Structural and compositional characterisation was done by auger electron spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy. Laser processing at lower fluence caused only oxidation of the top Ti layer, despite of the number of applied laser pulses. Interlayer mixing was not observed. Application of laser pulses at fluence of 0.11 J cm−2caused partial and/or complete ablation of deposited layers. In partially ablated regions considerable mixing between Ti and Ta films was registered.
T2  - Optical and Quantum Electronics
T1  - Laser induced mixing in multilayered Ti/Ta thin film structures
VL  - 50
IS  - 6
SP  - 257
DO  - 10.1007/s11082-018-1525-x
ER  - 

@article{
author = "Obradović, Marko O. and Kovač, Janez and Petrović, Suzana and Lazović, Vladimir M. and Salatić, Branislav and Ciganović, Jovan and Pjević, Dejan J. and Milosavljević, Momir and Peruško, Davor",
year = "2018",
abstract = "The possibility of interlayer mixing in a Ti/Ta multilayer system, induced by laser irradiation, was the main purpose of these experiments. Ti/Ta multilayer system, consisting of ten alternating Ti and Ta thin films and covered by slightly thicker Ti layer, was deposited on Si (100) wafers to a total thickness of 205 nm. Laser irradiation was performed in air by picoseconds Nd:YAG laser pulses in defocused regime with fluences of 0.057 and 0.11 J cm−2. Laser beam was scanned over the 5 × 5 mm surface area with different steps along y-axes. Structural and compositional characterisation was done by auger electron spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy. Laser processing at lower fluence caused only oxidation of the top Ti layer, despite of the number of applied laser pulses. Interlayer mixing was not observed. Application of laser pulses at fluence of 0.11 J cm−2caused partial and/or complete ablation of deposited layers. In partially ablated regions considerable mixing between Ti and Ta films was registered.",
journal = "Optical and Quantum Electronics",
title = "Laser induced mixing in multilayered Ti/Ta thin film structures",
volume = "50",
number = "6",
pages = "257",
doi = "10.1007/s11082-018-1525-x"
}

Obradović, M. O., Kovač, J., Petrović, S., Lazović, V. M., Salatić, B., Ciganović, J., Pjević, D. J., Milosavljević, M.,& Peruško, D.. (2018). Laser induced mixing in multilayered Ti/Ta thin film structures. in Optical and Quantum Electronics, 50(6), 257.
https://doi.org/10.1007/s11082-018-1525-x

Obradović MO, Kovač J, Petrović S, Lazović VM, Salatić B, Ciganović J, Pjević DJ, Milosavljević M, Peruško D. Laser induced mixing in multilayered Ti/Ta thin film structures. in Optical and Quantum Electronics. 2018;50(6):257.
doi:10.1007/s11082-018-1525-x .

Obradović, Marko O., Kovač, Janez, Petrović, Suzana, Lazović, Vladimir M., Salatić, Branislav, Ciganović, Jovan, Pjević, Dejan J., Milosavljević, Momir, Peruško, Davor, "Laser induced mixing in multilayered Ti/Ta thin film structures" in Optical and Quantum Electronics, 50, no. 6 (2018):257,
https://doi.org/10.1007/s11082-018-1525-x . .

TY  - JOUR
AU  - Jovanović, Zoran M.
AU  - Bajuk-Bogdanović, Danica V.
AU  - Jovanović, Sonja
AU  - Mravik, Željko
AU  - Kovač, Janez
AU  - Holclajtner-Antunović, Ivanka D.
AU  - Vujković, Milica
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1879
AB  - In the present study we have evaluated the contribution of particular oxygen functional groups in the charge storage properties of graphene oxide (GO). This was achieved by a gradual thermal reduction of GO in an inert atmosphere (up to 800 degrees C) and thorough examination of functional groups which remained after each de-functionalization step. After identification of functional groups, the character of additional cyclovoltammetric peak, less pronounced than the main redox quinone/hydroquinone pair, and overall charge storage properties of GO were discussed from the perspective of different thermal stability of its surface groups. The results indicated three-stage deoxidation process of GO, each comprising of specific surface chemistry, structural changes and electrochemical behavior. The low capacitance, similar to 50 F g(-1), at T LT = 300 degrees C was attributed to the presence of epoxy and carboxyl groups. The highest capacitance (120-130 F g(-1)) was observed in the case of GO reduced at 400 and 500 degrees C, which we attributed to positive effects of phenol and carbonyl/quinone groups, while at high temperatures (T GT = 600 degrees C, similar to 30 F g(-1)) the extensive desorption of functional groups and structural changes were emphasized as the main reasons for additional decrease of capacitance. Our results highlight the cases where the duality of interpretation of surface functional groups is likely to happen and indicate that not all functional groups play a positive role in charge storage behavior of graphene oxide. (C) 2017 Elsevier Ltd. All rights reserved.
T2  - Electrochimica Acta
T1  - The role of surface chemistry in the charge storage properties of graphene oxide
VL  - 258
SP  - 1228
EP  - 1243
DO  - 10.1016/j.electacta.2017.11.178
ER  - 

@article{
author = "Jovanović, Zoran M. and Bajuk-Bogdanović, Danica V. and Jovanović, Sonja and Mravik, Željko and Kovač, Janez and Holclajtner-Antunović, Ivanka D. and Vujković, Milica",
year = "2017",
abstract = "In the present study we have evaluated the contribution of particular oxygen functional groups in the charge storage properties of graphene oxide (GO). This was achieved by a gradual thermal reduction of GO in an inert atmosphere (up to 800 degrees C) and thorough examination of functional groups which remained after each de-functionalization step. After identification of functional groups, the character of additional cyclovoltammetric peak, less pronounced than the main redox quinone/hydroquinone pair, and overall charge storage properties of GO were discussed from the perspective of different thermal stability of its surface groups. The results indicated three-stage deoxidation process of GO, each comprising of specific surface chemistry, structural changes and electrochemical behavior. The low capacitance, similar to 50 F g(-1), at T LT = 300 degrees C was attributed to the presence of epoxy and carboxyl groups. The highest capacitance (120-130 F g(-1)) was observed in the case of GO reduced at 400 and 500 degrees C, which we attributed to positive effects of phenol and carbonyl/quinone groups, while at high temperatures (T GT = 600 degrees C, similar to 30 F g(-1)) the extensive desorption of functional groups and structural changes were emphasized as the main reasons for additional decrease of capacitance. Our results highlight the cases where the duality of interpretation of surface functional groups is likely to happen and indicate that not all functional groups play a positive role in charge storage behavior of graphene oxide. (C) 2017 Elsevier Ltd. All rights reserved.",
journal = "Electrochimica Acta",
title = "The role of surface chemistry in the charge storage properties of graphene oxide",
volume = "258",
pages = "1228-1243",
doi = "10.1016/j.electacta.2017.11.178"
}

Jovanović, Z. M., Bajuk-Bogdanović, D. V., Jovanović, S., Mravik, Ž., Kovač, J., Holclajtner-Antunović, I. D.,& Vujković, M.. (2017). The role of surface chemistry in the charge storage properties of graphene oxide. in Electrochimica Acta, 258, 1228-1243.
https://doi.org/10.1016/j.electacta.2017.11.178

Jovanović ZM, Bajuk-Bogdanović DV, Jovanović S, Mravik Ž, Kovač J, Holclajtner-Antunović ID, Vujković M. The role of surface chemistry in the charge storage properties of graphene oxide. in Electrochimica Acta. 2017;258:1228-1243.
doi:10.1016/j.electacta.2017.11.178 .

Jovanović, Zoran M., Bajuk-Bogdanović, Danica V., Jovanović, Sonja, Mravik, Željko, Kovač, Janez, Holclajtner-Antunović, Ivanka D., Vujković, Milica, "The role of surface chemistry in the charge storage properties of graphene oxide" in Electrochimica Acta, 258 (2017):1228-1243,
https://doi.org/10.1016/j.electacta.2017.11.178 . .

TY  - CONF
AU  - Obradović, Marko O.
AU  - Kovač, Janez
AU  - Petrović, Suzana
AU  - Lazović, Vladimir M.
AU  - Salatić, Branislav
AU  - Ciganović, Jovan
AU  - Pjević, Dejan J.
AU  - Milosavljević, Momir
AU  - Peruško, Davor
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10948
AB  - Metallic biomaterials should exhibit excellent biocompatibility, high corrosion resistance and low elastic modulus which are close to that of human bones. It was shown that in this sence Ti-Ta alloys have considerably better mechanical properties compared to pure titanium or tantalum [1, 2]. The main purpose of these experiments was investigation of possibility to induce interlayer mixing in an Ti/Ta immiscible multilayer system by laser irradiation.The absence of interlayer mixing was previously shown on this system during the Ar+ ion irradiation up to relatively high fluence of 2x1016 ions cm-2 [3]. The system consisted of ten alternate Ti and Ta thin films (~18 nm each) and covered by slightly thicker Ti layer (~27 nm) on the top with the purpose of creating an appropriate porous structure very important for potential biocompatibility [4]. Structure was deposited on Si (100) wafers to a total thickness of 205 nm. Laser irradiation was performed in air by picoseconds Nd: YAG laser. Defocused laser pulses had a laser spot on the sample surface of 3 mm in diameter and fluences of 0.057 and 0.11 J cm-2 . Laser beam was scanned over the 5x5 mm2 surface area with different steps along y-axes to provide a variation in deposited energy density. For structural and compositional characterisation following methods were used: Auger electron spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy and scanning electron microscopy. The obtained results show that laser processing at a lower fluence causes only oxidation of the top Ti layer, invariable to the number of applied laser pulses and no interlayer mixing was observed. Appliance of laser pulses at fluence of 0.11 J cm-2 , on the other hand, caused significant increase of surface roughness and partial and/or complete ablation of deposited layers, but in partially ablated regions considerable mixing between Ti and Ta films was registered. These experiments indicate that the use of picoseconds laser pulses with fluences in interval (0.057 – 0.11) J cm-2 could be very useful for mixing of titanium and tantalum layers and fabrication of a new material for medical implants. Suitable choice of films thicknesses would lead to the desired composition of this alloy.
PB  - Belgrade : Institute of Physics Belgrade
C3  - PHOTONICA2017 : 6th International School and Conference on Photonics and COST actions: MP1406 and MP1402 : Program and the book of abstracts
T1  - Laser induced mixing in multilayered Ti/Ta thin film structures
SP  - 182
UR  - https://hdl.handle.net/21.15107/rcub_vinar_10948
ER  - 

@conference{
author = "Obradović, Marko O. and Kovač, Janez and Petrović, Suzana and Lazović, Vladimir M. and Salatić, Branislav and Ciganović, Jovan and Pjević, Dejan J. and Milosavljević, Momir and Peruško, Davor",
year = "2017",
abstract = "Metallic biomaterials should exhibit excellent biocompatibility, high corrosion resistance and low elastic modulus which are close to that of human bones. It was shown that in this sence Ti-Ta alloys have considerably better mechanical properties compared to pure titanium or tantalum [1, 2]. The main purpose of these experiments was investigation of possibility to induce interlayer mixing in an Ti/Ta immiscible multilayer system by laser irradiation.The absence of interlayer mixing was previously shown on this system during the Ar+ ion irradiation up to relatively high fluence of 2x1016 ions cm-2 [3]. The system consisted of ten alternate Ti and Ta thin films (~18 nm each) and covered by slightly thicker Ti layer (~27 nm) on the top with the purpose of creating an appropriate porous structure very important for potential biocompatibility [4]. Structure was deposited on Si (100) wafers to a total thickness of 205 nm. Laser irradiation was performed in air by picoseconds Nd: YAG laser. Defocused laser pulses had a laser spot on the sample surface of 3 mm in diameter and fluences of 0.057 and 0.11 J cm-2 . Laser beam was scanned over the 5x5 mm2 surface area with different steps along y-axes to provide a variation in deposited energy density. For structural and compositional characterisation following methods were used: Auger electron spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy and scanning electron microscopy. The obtained results show that laser processing at a lower fluence causes only oxidation of the top Ti layer, invariable to the number of applied laser pulses and no interlayer mixing was observed. Appliance of laser pulses at fluence of 0.11 J cm-2 , on the other hand, caused significant increase of surface roughness and partial and/or complete ablation of deposited layers, but in partially ablated regions considerable mixing between Ti and Ta films was registered. These experiments indicate that the use of picoseconds laser pulses with fluences in interval (0.057 – 0.11) J cm-2 could be very useful for mixing of titanium and tantalum layers and fabrication of a new material for medical implants. Suitable choice of films thicknesses would lead to the desired composition of this alloy.",
publisher = "Belgrade : Institute of Physics Belgrade",
journal = "PHOTONICA2017 : 6th International School and Conference on Photonics and COST actions: MP1406 and MP1402 : Program and the book of abstracts",
title = "Laser induced mixing in multilayered Ti/Ta thin film structures",
pages = "182",
url = "https://hdl.handle.net/21.15107/rcub_vinar_10948"
}

Obradović, M. O., Kovač, J., Petrović, S., Lazović, V. M., Salatić, B., Ciganović, J., Pjević, D. J., Milosavljević, M.,& Peruško, D.. (2017). Laser induced mixing in multilayered Ti/Ta thin film structures. in PHOTONICA2017 : 6th International School and Conference on Photonics and COST actions: MP1406 and MP1402 : Program and the book of abstracts
Belgrade : Institute of Physics Belgrade., 182.
https://hdl.handle.net/21.15107/rcub_vinar_10948

Obradović MO, Kovač J, Petrović S, Lazović VM, Salatić B, Ciganović J, Pjević DJ, Milosavljević M, Peruško D. Laser induced mixing in multilayered Ti/Ta thin film structures. in PHOTONICA2017 : 6th International School and Conference on Photonics and COST actions: MP1406 and MP1402 : Program and the book of abstracts. 2017;:182.
https://hdl.handle.net/21.15107/rcub_vinar_10948 .

Obradović, Marko O., Kovač, Janez, Petrović, Suzana, Lazović, Vladimir M., Salatić, Branislav, Ciganović, Jovan, Pjević, Dejan J., Milosavljević, Momir, Peruško, Davor, "Laser induced mixing in multilayered Ti/Ta thin film structures" in PHOTONICA2017 : 6th International School and Conference on Photonics and COST actions: MP1406 and MP1402 : Program and the book of abstracts (2017):182,
https://hdl.handle.net/21.15107/rcub_vinar_10948 .

TY  - JOUR
AU  - Peruško, Davor
AU  - Kovač, Janez
AU  - Petrović, Suzana
AU  - Obradović, Marko O.
AU  - Mitrić, Miodrag
AU  - Pavlović, Vladimir B.
AU  - Salatić, Branislav
AU  - Jaksa, G.
AU  - Ciganović, Jovan
AU  - Milosavljević, Momir
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1725
AB  - Multilayers consisting of five (Al/Ti) bilayers were deposited on (100) silicon wafers. On top was deposited the Ti layer, aimed at preventing Al from diffusing to the surface upon laser treatment. The total thickness of the thin-film structure was 200 nm. Laser irradiations with Nd:YAG picoseconds laser pulses in the defocused regime were performed in air. Laser beam energy was 4 mJ and laser spot diameter on the sample surface was 3 mm (fluence 0.057 J cm(-2)). The samples were treated with different numbers of laser pulses. Structural characterizations were performed by different analytical methods and nano-hardness was also measured. Laser processing induced layer intermixing, formation of titanium aluminides, oxidation of the surface titanium layer and enhanced surface roughness. Aluminum appears at the sample surface only for the highest density of laser irradiation. Laser processing induces increment of nano-hardness by approximately 20% and decrease of residual Youngs modulus for a few percentages from the starting value of the untreated samples. These results can be interesting toward achieving structures with a selective extent of Al-Ti reactivity in this multilayered system, within the development of biocompatible materials.
T2  - Materials and Manufacturing Processes
T1  - Selective Al-Ti reactivity in laser-processed Al/Ti multilayers
VL  - 32
IS  - 14
SP  - 1622
EP  - 1627
DO  - 10.1080/10426914.2017.1279299
ER  - 

@article{
author = "Peruško, Davor and Kovač, Janez and Petrović, Suzana and Obradović, Marko O. and Mitrić, Miodrag and Pavlović, Vladimir B. and Salatić, Branislav and Jaksa, G. and Ciganović, Jovan and Milosavljević, Momir",
year = "2017",
abstract = "Multilayers consisting of five (Al/Ti) bilayers were deposited on (100) silicon wafers. On top was deposited the Ti layer, aimed at preventing Al from diffusing to the surface upon laser treatment. The total thickness of the thin-film structure was 200 nm. Laser irradiations with Nd:YAG picoseconds laser pulses in the defocused regime were performed in air. Laser beam energy was 4 mJ and laser spot diameter on the sample surface was 3 mm (fluence 0.057 J cm(-2)). The samples were treated with different numbers of laser pulses. Structural characterizations were performed by different analytical methods and nano-hardness was also measured. Laser processing induced layer intermixing, formation of titanium aluminides, oxidation of the surface titanium layer and enhanced surface roughness. Aluminum appears at the sample surface only for the highest density of laser irradiation. Laser processing induces increment of nano-hardness by approximately 20% and decrease of residual Youngs modulus for a few percentages from the starting value of the untreated samples. These results can be interesting toward achieving structures with a selective extent of Al-Ti reactivity in this multilayered system, within the development of biocompatible materials.",
journal = "Materials and Manufacturing Processes",
title = "Selective Al-Ti reactivity in laser-processed Al/Ti multilayers",
volume = "32",
number = "14",
pages = "1622-1627",
doi = "10.1080/10426914.2017.1279299"
}

Peruško, D., Kovač, J., Petrović, S., Obradović, M. O., Mitrić, M., Pavlović, V. B., Salatić, B., Jaksa, G., Ciganović, J.,& Milosavljević, M.. (2017). Selective Al-Ti reactivity in laser-processed Al/Ti multilayers. in Materials and Manufacturing Processes, 32(14), 1622-1627.
https://doi.org/10.1080/10426914.2017.1279299

Peruško D, Kovač J, Petrović S, Obradović MO, Mitrić M, Pavlović VB, Salatić B, Jaksa G, Ciganović J, Milosavljević M. Selective Al-Ti reactivity in laser-processed Al/Ti multilayers. in Materials and Manufacturing Processes. 2017;32(14):1622-1627.
doi:10.1080/10426914.2017.1279299 .

Peruško, Davor, Kovač, Janez, Petrović, Suzana, Obradović, Marko O., Mitrić, Miodrag, Pavlović, Vladimir B., Salatić, Branislav, Jaksa, G., Ciganović, Jovan, Milosavljević, Momir, "Selective Al-Ti reactivity in laser-processed Al/Ti multilayers" in Materials and Manufacturing Processes, 32, no. 14 (2017):1622-1627,
https://doi.org/10.1080/10426914.2017.1279299 . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Peruško, Davor
AU  - Kovač, Janez
AU  - Panjan, Peter
AU  - Mitrić, Miodrag
AU  - Pjević, Dejan J.
AU  - Kovačević, Aleksander
AU  - Jelenković, Branislav
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1746
AB  - Formation of periodic nanostructures on the Ti/5x(Al/Ti)/Si multilayers induced by picosecond laser pulses is studied in order to better understand the formation of a laser-induced periodic surface structure (LIPSS). At fluence slightly below the ablation threshold, the formation of low spatial frequency-LIPSS (LSFL) oriented perpendicular to the direction of the laser polarization is observed on the irradiated area. Prolonged irradiation while scanning results in the formation of a high spatial frequency-LIPSS (HSFL), on top of the LSFLs, creating a co-existence parallel periodic structure. HSFL was oriented parallel to the incident laser polarization. Intermixing between the Al and Ti layers with the formation of Al-Ti intermetallic compounds was achieved during the irradiation. The intermetallic region was formed mostly within the heat affected zone of the sample. Surface segregation of aluminium with partial ablation of the top layer of titanium was followed by the formation of an ultra-thin Al2O3 film on the surface of the multi-layered structure. Published by AIP Publishing.
T2  - Journal of Applied Physics
T1  - Design of co-existence parallel periodic surface structure induced by picosecond laser pulses on the Al/Ti multilayers
VL  - 122
IS  - 11
DO  - 10.1063/1.4985830
ER  - 

@article{
author = "Petrović, Suzana and Peruško, Davor and Kovač, Janez and Panjan, Peter and Mitrić, Miodrag and Pjević, Dejan J. and Kovačević, Aleksander and Jelenković, Branislav",
year = "2017",
abstract = "Formation of periodic nanostructures on the Ti/5x(Al/Ti)/Si multilayers induced by picosecond laser pulses is studied in order to better understand the formation of a laser-induced periodic surface structure (LIPSS). At fluence slightly below the ablation threshold, the formation of low spatial frequency-LIPSS (LSFL) oriented perpendicular to the direction of the laser polarization is observed on the irradiated area. Prolonged irradiation while scanning results in the formation of a high spatial frequency-LIPSS (HSFL), on top of the LSFLs, creating a co-existence parallel periodic structure. HSFL was oriented parallel to the incident laser polarization. Intermixing between the Al and Ti layers with the formation of Al-Ti intermetallic compounds was achieved during the irradiation. The intermetallic region was formed mostly within the heat affected zone of the sample. Surface segregation of aluminium with partial ablation of the top layer of titanium was followed by the formation of an ultra-thin Al2O3 film on the surface of the multi-layered structure. Published by AIP Publishing.",
journal = "Journal of Applied Physics",
title = "Design of co-existence parallel periodic surface structure induced by picosecond laser pulses on the Al/Ti multilayers",
volume = "122",
number = "11",
doi = "10.1063/1.4985830"
}

Petrović, S., Peruško, D., Kovač, J., Panjan, P., Mitrić, M., Pjević, D. J., Kovačević, A.,& Jelenković, B.. (2017). Design of co-existence parallel periodic surface structure induced by picosecond laser pulses on the Al/Ti multilayers. in Journal of Applied Physics, 122(11).
https://doi.org/10.1063/1.4985830

Petrović S, Peruško D, Kovač J, Panjan P, Mitrić M, Pjević DJ, Kovačević A, Jelenković B. Design of co-existence parallel periodic surface structure induced by picosecond laser pulses on the Al/Ti multilayers. in Journal of Applied Physics. 2017;122(11).
doi:10.1063/1.4985830 .

Petrović, Suzana, Peruško, Davor, Kovač, Janez, Panjan, Peter, Mitrić, Miodrag, Pjević, Dejan J., Kovačević, Aleksander, Jelenković, Branislav, "Design of co-existence parallel periodic surface structure induced by picosecond laser pulses on the Al/Ti multilayers" in Journal of Applied Physics, 122, no. 11 (2017),
https://doi.org/10.1063/1.4985830 . .

TY  - JOUR
AU  - Albrbar, Asma Juma
AU  - Đokić, Veljko R.
AU  - Bjelajac, Anđelika
AU  - Kovač, Janez
AU  - Ćirković, Jovana
AU  - Mitrić, Miodrag
AU  - Janaćković, Đorđe T.
AU  - Petrović, Rada
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1261
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. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
T2  - Ceramics International
T1  - Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route
VL  - 42
IS  - 15
SP  - 16718
EP  - 16728
DO  - 10.1016/j.ceramint.2016.07.144
ER  - 

@article{
author = "Albrbar, Asma Juma and Đokić, Veljko R. and Bjelajac, Anđelika and Kovač, Janez and Ćirković, Jovana and Mitrić, Miodrag and Janaćković, Đorđe T. 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. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.",
journal = "Ceramics International",
title = "Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route",
volume = "42",
number = "15",
pages = "16718-16728",
doi = "10.1016/j.ceramint.2016.07.144"
}

Albrbar, A. J., Đokić, V. R., Bjelajac, A., Kovač, J., Ćirković, J., Mitrić, M., Janaćković, Đ. T.,& 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, 42(15), 16718-16728.
https://doi.org/10.1016/j.ceramint.2016.07.144

Albrbar AJ, Đokić VR, Bjelajac A, Kovač J, Ćirković J, Mitrić M, Janaćković ĐT, 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 R., Bjelajac, Anđelika, Kovač, Janez, Ćirković, Jovana, Mitrić, Miodrag, Janaćković, Đorđe T., 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  - Petrović, Suzana
AU  - Milovanović, Dubravka S.
AU  - Salatić, Branislav
AU  - Peruško, Davor
AU  - Kovač, Janez
AU  - Dražić, Goran
AU  - Mitrić, Miodrag
AU  - Trtica, Milan
AU  - Jelenković, Branislav
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/807
AB  - Bimetallic NiAu and complex NiO:Au nanoparticles were formed by laser ablation of Ni target immersed in the colloidal gold solution. Effect of laser parameters (pulse duration, fluences and ablation times) on size and composition of nanoparticles was investigated by ablating the target with two Nd:YAG lasers at 1064 nm, operating with different pulse durations, 150 ps and 20 ns. Stronger ablation of the Ni target and subsequient synthesis of nanoparticles is achieved with picosecond pulses, compared to the nanoparticles production with nanosecond pulses, because the former ablation induces activation of different reactions between species in the colloidal solution. Shape, size and composition of the synthesized nanopraticles were found to correlate with the concentration of Ni species in the colloidal solution. Higher Ni concentration leads to formation of larger NiAu nanoparticles in form of solid solution. Smaller nanoparticles with lower Ni concentration in the colloidal solution were achieved by their synthesis during nanosecond pulses, when the obtained distribution of composition corresponds to the NiO matrix with incorporated golden nanoparticles. The results also demonstrate that the formation of bimetallic NiAu and complex NiO:Au nanoparticles were possible by means of laser ablation in liquids. (C) 2015 Elsevier B.V. All rights reserved.
PB  - Elsevier
T2  - Materials Chemistry and Physics
T1  - Composition and structure of NiAu nanoparticles formed by laser ablation of Ni target in Au colloidal solution
VL  - 166
SP  - 223
EP  - 232
DO  - 10.1016/j.matchemphys.2015.10.007
ER  - 

@article{
author = "Petrović, Suzana and Milovanović, Dubravka S. and Salatić, Branislav and Peruško, Davor and Kovač, Janez and Dražić, Goran and Mitrić, Miodrag and Trtica, Milan and Jelenković, Branislav",
year = "2015",
abstract = "Bimetallic NiAu and complex NiO:Au nanoparticles were formed by laser ablation of Ni target immersed in the colloidal gold solution. Effect of laser parameters (pulse duration, fluences and ablation times) on size and composition of nanoparticles was investigated by ablating the target with two Nd:YAG lasers at 1064 nm, operating with different pulse durations, 150 ps and 20 ns. Stronger ablation of the Ni target and subsequient synthesis of nanoparticles is achieved with picosecond pulses, compared to the nanoparticles production with nanosecond pulses, because the former ablation induces activation of different reactions between species in the colloidal solution. Shape, size and composition of the synthesized nanopraticles were found to correlate with the concentration of Ni species in the colloidal solution. Higher Ni concentration leads to formation of larger NiAu nanoparticles in form of solid solution. Smaller nanoparticles with lower Ni concentration in the colloidal solution were achieved by their synthesis during nanosecond pulses, when the obtained distribution of composition corresponds to the NiO matrix with incorporated golden nanoparticles. The results also demonstrate that the formation of bimetallic NiAu and complex NiO:Au nanoparticles were possible by means of laser ablation in liquids. (C) 2015 Elsevier B.V. All rights reserved.",
publisher = "Elsevier",
journal = "Materials Chemistry and Physics",
title = "Composition and structure of NiAu nanoparticles formed by laser ablation of Ni target in Au colloidal solution",
volume = "166",
pages = "223-232",
doi = "10.1016/j.matchemphys.2015.10.007"
}

Petrović, S., Milovanović, D. S., Salatić, B., Peruško, D., Kovač, J., Dražić, G., Mitrić, M., Trtica, M.,& Jelenković, B.. (2015). Composition and structure of NiAu nanoparticles formed by laser ablation of Ni target in Au colloidal solution. in Materials Chemistry and Physics
Elsevier., 166, 223-232.
https://doi.org/10.1016/j.matchemphys.2015.10.007

Petrović S, Milovanović DS, Salatić B, Peruško D, Kovač J, Dražić G, Mitrić M, Trtica M, Jelenković B. Composition and structure of NiAu nanoparticles formed by laser ablation of Ni target in Au colloidal solution. in Materials Chemistry and Physics. 2015;166:223-232.
doi:10.1016/j.matchemphys.2015.10.007 .

Petrović, Suzana, Milovanović, Dubravka S., Salatić, Branislav, Peruško, Davor, Kovač, Janez, Dražić, Goran, Mitrić, Miodrag, Trtica, Milan, Jelenković, Branislav, "Composition and structure of NiAu nanoparticles formed by laser ablation of Ni target in Au colloidal solution" in Materials Chemistry and Physics, 166 (2015):223-232,
https://doi.org/10.1016/j.matchemphys.2015.10.007 . .

TY  - JOUR
AU  - Peruško, Davor
AU  - Kovač, Janez
AU  - Petrović, Suzana
AU  - Dražić, Goran
AU  - Mitrić, Miodrag
AU  - Milosavljević, Momir
AU  - Ciganović, Jovan
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7080
AB  - Multilayer structures, consisting of 15 alternate Ti and Al thin films, and covered with thicker Ti layer, were deposited on a Si substrate to a total thickness of 900 nm. Laser treatment was performed in air by defocused Nd:YAG laser pulses (150 ps) with energies of 7 and 10 mJ covering an area of 3 mm in diameter (fluences were 0.1 and 0.14 J cm(-2) respectively). Laser beam was scanned over the 5 x 5 mm surface area. Characterizations were done by Auger electron spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy and transmission electron microscopy. Nano-hardness measurements were performed by Vickers method with applied load of 5 mN. Obtained results show that irradiation with picosecond laser pulses leads to the formation of Ti2O3 in the top Ti layer. This process is more pronounced for higher energy and/or higher number of applied laser pulses. On the surface of all samples very thin amorphous TiO2 layer was formed. Laser irradiation induces surface melting and transformation of relatively flat surface into mosaic shaped one for samples treated with higher energy and higher number of applied laser pulses. Irradiation at smaller energy did not induce any noticeably mixing between Al and Ti beneath the covered Ti layer. Some mixing of Al and Ti appeared in the sample irradiated with higher energy of laser pulses. (C) 2015 Elsevier B.V. All rights reserved.
T2  - Thin Solid Films
T1  - Intermixing and phase transformations in Al/Ti multilayer system induced by picosecond laser beam
VL  - 591
SP  - 357
EP  - 362
DO  - 10.1016/j.tsf.2015.03.030
ER  - 

@article{
author = "Peruško, Davor and Kovač, Janez and Petrović, Suzana and Dražić, Goran and Mitrić, Miodrag and Milosavljević, Momir and Ciganović, Jovan",
year = "2015",
abstract = "Multilayer structures, consisting of 15 alternate Ti and Al thin films, and covered with thicker Ti layer, were deposited on a Si substrate to a total thickness of 900 nm. Laser treatment was performed in air by defocused Nd:YAG laser pulses (150 ps) with energies of 7 and 10 mJ covering an area of 3 mm in diameter (fluences were 0.1 and 0.14 J cm(-2) respectively). Laser beam was scanned over the 5 x 5 mm surface area. Characterizations were done by Auger electron spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy and transmission electron microscopy. Nano-hardness measurements were performed by Vickers method with applied load of 5 mN. Obtained results show that irradiation with picosecond laser pulses leads to the formation of Ti2O3 in the top Ti layer. This process is more pronounced for higher energy and/or higher number of applied laser pulses. On the surface of all samples very thin amorphous TiO2 layer was formed. Laser irradiation induces surface melting and transformation of relatively flat surface into mosaic shaped one for samples treated with higher energy and higher number of applied laser pulses. Irradiation at smaller energy did not induce any noticeably mixing between Al and Ti beneath the covered Ti layer. Some mixing of Al and Ti appeared in the sample irradiated with higher energy of laser pulses. (C) 2015 Elsevier B.V. All rights reserved.",
journal = "Thin Solid Films",
title = "Intermixing and phase transformations in Al/Ti multilayer system induced by picosecond laser beam",
volume = "591",
pages = "357-362",
doi = "10.1016/j.tsf.2015.03.030"
}

Peruško, D., Kovač, J., Petrović, S., Dražić, G., Mitrić, M., Milosavljević, M.,& Ciganović, J.. (2015). Intermixing and phase transformations in Al/Ti multilayer system induced by picosecond laser beam. in Thin Solid Films, 591, 357-362.
https://doi.org/10.1016/j.tsf.2015.03.030

Peruško D, Kovač J, Petrović S, Dražić G, Mitrić M, Milosavljević M, Ciganović J. Intermixing and phase transformations in Al/Ti multilayer system induced by picosecond laser beam. in Thin Solid Films. 2015;591:357-362.
doi:10.1016/j.tsf.2015.03.030 .

Peruško, Davor, Kovač, Janez, Petrović, Suzana, Dražić, Goran, Mitrić, Miodrag, Milosavljević, Momir, Ciganović, Jovan, "Intermixing and phase transformations in Al/Ti multilayer system induced by picosecond laser beam" in Thin Solid Films, 591 (2015):357-362,
https://doi.org/10.1016/j.tsf.2015.03.030 . .

TY  - JOUR
AU  - Elezovic, N. R.
AU  - Radmilovíć, Velimir R.
AU  - Kovač, Janez
AU  - Babić, Biljana M.
AU  - Gajic-Krstajic, Lj. M.
AU  - Krstajic, N. V.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/404
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.
T2  - RSC Advances
T1  - Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions
VL  - 5
IS  - 21
SP  - 15923
EP  - 15929
DO  - 10.1039/c4ra13391a
ER  - 

@article{
author = "Elezovic, N. R. and Radmilovíć, Velimir R. and Kovač, Janez and Babić, Biljana M. and Gajic-Krstajic, Lj. M. and Krstajic, N. V.",
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.",
journal = "RSC Advances",
title = "Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions",
volume = "5",
number = "21",
pages = "15923-15929",
doi = "10.1039/c4ra13391a"
}

Elezovic, N. R., Radmilovíć, V. R., Kovač, J., Babić, B. M., Gajic-Krstajic, Lj. M.,& Krstajic, N. V.. (2015). Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions. in RSC Advances, 5(21), 15923-15929.
https://doi.org/10.1039/c4ra13391a

Elezovic NR, Radmilovíć VR, Kovač J, Babić BM, Gajic-Krstajic LM, Krstajic NV. 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 .

Elezovic, N. R., Radmilovíć, Velimir R., Kovač, Janez, Babić, Biljana M., Gajic-Krstajic, Lj. M., Krstajic, N. V., "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 . .

TY  - JOUR
AU  - Elezovic, N. R.
AU  - Ercius, P.
AU  - Kovač, Janez
AU  - Radmilovíć, Velimir R.
AU  - Babić, Biljana M.
AU  - Krstajic, N. V.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/420
AB  - Ruthenium oxide/titanium oxide, with a Ru:Ti atomic ratio of 7:3 was synthesized by modified sol-gel procedure and used as a support for platinum nanocatalyst for oxygen reduction reaction. The synthesized materials were characterized in terms of morphology, particle size distribution, chemical and phase composition by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high angle annular dark filed scanning transmission electron microscopy (HAADF, STEM) and electron energy loss spectroscopy (EELS). XPS spectra revealed that Ru atoms were in mainly in Ru(4+) oxidation state, the Ti atoms in Ti(4+) oxidation state, whereas the Pt-atoms were in metallic state. TEM analysis proved that platinum nanoparticles nucleated at both oxide species and homogeneous distribution was observed. The average platinum nanoparticle size was 3.05 nm. Electrochemically active surface area of platinum was 32 m(2) g(-1). Kinetics of the oxygen reduction was studied at rotating disc electrode in 0.5 mol dm(-3) HClO4 solution, at 25 degrees C. The catalytic activities expressed in terms of specific activity (per electrochemically active surface area of platinum) and mass activity (per mass of platinum) were determined and compared to Pt catalyst on carbon support. The high catalytic activity was proven by electrochemical characterization. (C) 2014 Elsevier B.V. All rights reserved.
T2  - Journal of Electroanalytical Chemistry
T1  - Synthesis and characterization of Pt nanocatalyst on Ru0.7Ti0.3O2 support as a cathode for fuel cells application
VL  - 739
SP  - 164
EP  - 171
DO  - 10.1016/j.jelechem.2014.12.033
ER  - 

@article{
author = "Elezovic, N. R. and Ercius, P. and Kovač, Janez and Radmilovíć, Velimir R. and Babić, Biljana M. and Krstajic, N. V.",
year = "2015",
abstract = "Ruthenium oxide/titanium oxide, with a Ru:Ti atomic ratio of 7:3 was synthesized by modified sol-gel procedure and used as a support for platinum nanocatalyst for oxygen reduction reaction. The synthesized materials were characterized in terms of morphology, particle size distribution, chemical and phase composition by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high angle annular dark filed scanning transmission electron microscopy (HAADF, STEM) and electron energy loss spectroscopy (EELS). XPS spectra revealed that Ru atoms were in mainly in Ru(4+) oxidation state, the Ti atoms in Ti(4+) oxidation state, whereas the Pt-atoms were in metallic state. TEM analysis proved that platinum nanoparticles nucleated at both oxide species and homogeneous distribution was observed. The average platinum nanoparticle size was 3.05 nm. Electrochemically active surface area of platinum was 32 m(2) g(-1). Kinetics of the oxygen reduction was studied at rotating disc electrode in 0.5 mol dm(-3) HClO4 solution, at 25 degrees C. The catalytic activities expressed in terms of specific activity (per electrochemically active surface area of platinum) and mass activity (per mass of platinum) were determined and compared to Pt catalyst on carbon support. The high catalytic activity was proven by electrochemical characterization. (C) 2014 Elsevier B.V. All rights reserved.",
journal = "Journal of Electroanalytical Chemistry",
title = "Synthesis and characterization of Pt nanocatalyst on Ru0.7Ti0.3O2 support as a cathode for fuel cells application",
volume = "739",
pages = "164-171",
doi = "10.1016/j.jelechem.2014.12.033"
}

Elezovic, N. R., Ercius, P., Kovač, J., Radmilovíć, V. R., Babić, B. M.,& Krstajic, N. V.. (2015). Synthesis and characterization of Pt nanocatalyst on Ru0.7Ti0.3O2 support as a cathode for fuel cells application. in Journal of Electroanalytical Chemistry, 739, 164-171.
https://doi.org/10.1016/j.jelechem.2014.12.033

Elezovic NR, Ercius P, Kovač J, Radmilovíć VR, Babić BM, Krstajic NV. Synthesis and characterization of Pt nanocatalyst on Ru0.7Ti0.3O2 support as a cathode for fuel cells application. in Journal of Electroanalytical Chemistry. 2015;739:164-171.
doi:10.1016/j.jelechem.2014.12.033 .

Elezovic, N. R., Ercius, P., Kovač, Janez, Radmilovíć, Velimir R., Babić, Biljana M., Krstajic, N. V., "Synthesis and characterization of Pt nanocatalyst on Ru0.7Ti0.3O2 support as a cathode for fuel cells application" in Journal of Electroanalytical Chemistry, 739 (2015):164-171,
https://doi.org/10.1016/j.jelechem.2014.12.033 . .

TY  - JOUR
AU  - Petrović, Suzana
AU  - Gaković, Biljana M.
AU  - Kovač, Janez
AU  - Panjan, Peter
AU  - Stratakis, Emmanuel
AU  - Trtica, Milan
AU  - Fotakis, C.
AU  - Jelenković, Branislav
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/103
AB  - The conditions of ultra-thin oxide films synthesized as the Al/Fe multilayer structures after the surface treatment with femtosecond laser radiation were studied. Thin films composed of three (Al/Fe) bilayers were deposited by DC ion sputtering on (100) Si wafers to the total thickness of 410 nm. Laser irradiations were performed by 40-fs pulses of a Ti:Sapphire laser operating at 800 nm, at fluences slightly higher than the ablation threshold. The samples were characterized by Auger electron spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Progressed intermixing of components was achieved for the irradiation with fluence of 0.43 J cm(-2), when intermetallic phase was formed and all components were almost uniformly distributed through the entire multilayer structure. Exception is the subsurface region, to the thickness of 20 nm, where the distribution of constructive components and their oxide is changing with the distance from the surface, and this distribution depends on the applied laser fluences. An ultra-thin oxide layer was formed at the surface, with the specific combination of the oxide phases, Al2O3 and Fe2O3, depending on the applied fluences. Laser-induced modification was accompanied with the ablation of the material and the creation of parallel periodic structures. These effects of laser-induced morphological features are increased with increasing laser fluences, caused by the pronounced mobility of the materials. The special morphology of the laser-assisted synthesis of mixture of Al2O3 and Fe2O3 in the form of an ultra-thin oxide layer can improve their characteristics for functional applications, as catalysts and sensors.
T2  - Journal of Materials Science
T1  - Synthesis of ultra-thin oxide layer in laser-treated 3x (Al/Fe)/Si multilayer structure
VL  - 49
IS  - 22
SP  - 7900
EP  - 7907
DO  - 10.1007/s10853-014-8502-y
ER  - 

@article{
author = "Petrović, Suzana and Gaković, Biljana M. and Kovač, Janez and Panjan, Peter and Stratakis, Emmanuel and Trtica, Milan and Fotakis, C. and Jelenković, Branislav",
year = "2014",
abstract = "The conditions of ultra-thin oxide films synthesized as the Al/Fe multilayer structures after the surface treatment with femtosecond laser radiation were studied. Thin films composed of three (Al/Fe) bilayers were deposited by DC ion sputtering on (100) Si wafers to the total thickness of 410 nm. Laser irradiations were performed by 40-fs pulses of a Ti:Sapphire laser operating at 800 nm, at fluences slightly higher than the ablation threshold. The samples were characterized by Auger electron spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Progressed intermixing of components was achieved for the irradiation with fluence of 0.43 J cm(-2), when intermetallic phase was formed and all components were almost uniformly distributed through the entire multilayer structure. Exception is the subsurface region, to the thickness of 20 nm, where the distribution of constructive components and their oxide is changing with the distance from the surface, and this distribution depends on the applied laser fluences. An ultra-thin oxide layer was formed at the surface, with the specific combination of the oxide phases, Al2O3 and Fe2O3, depending on the applied fluences. Laser-induced modification was accompanied with the ablation of the material and the creation of parallel periodic structures. These effects of laser-induced morphological features are increased with increasing laser fluences, caused by the pronounced mobility of the materials. The special morphology of the laser-assisted synthesis of mixture of Al2O3 and Fe2O3 in the form of an ultra-thin oxide layer can improve their characteristics for functional applications, as catalysts and sensors.",
journal = "Journal of Materials Science",
title = "Synthesis of ultra-thin oxide layer in laser-treated 3x (Al/Fe)/Si multilayer structure",
volume = "49",
number = "22",
pages = "7900-7907",
doi = "10.1007/s10853-014-8502-y"
}

Petrović, S., Gaković, B. M., Kovač, J., Panjan, P., Stratakis, E., Trtica, M., Fotakis, C.,& Jelenković, B.. (2014). Synthesis of ultra-thin oxide layer in laser-treated 3x (Al/Fe)/Si multilayer structure. in Journal of Materials Science, 49(22), 7900-7907.
https://doi.org/10.1007/s10853-014-8502-y

Petrović S, Gaković BM, Kovač J, Panjan P, Stratakis E, Trtica M, Fotakis C, Jelenković B. Synthesis of ultra-thin oxide layer in laser-treated 3x (Al/Fe)/Si multilayer structure. in Journal of Materials Science. 2014;49(22):7900-7907.
doi:10.1007/s10853-014-8502-y .

Petrović, Suzana, Gaković, Biljana M., Kovač, Janez, Panjan, Peter, Stratakis, Emmanuel, Trtica, Milan, Fotakis, C., Jelenković, Branislav, "Synthesis of ultra-thin oxide layer in laser-treated 3x (Al/Fe)/Si multilayer structure" in Journal of Materials Science, 49, no. 22 (2014):7900-7907,
https://doi.org/10.1007/s10853-014-8502-y . .

TY  - JOUR
AU  - Zentkova, M.
AU  - Lazurova, J.
AU  - Kovač, Janez
AU  - Mihalik, M.
AU  - Mihalik, Jr., M.
AU  - Briancin, J.
AU  - Fitta, M.
AU  - Kusigerski, Vladan
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7034
AB  - In our paper we study effect of Mn for Fe substitution on magnetic properties of NdFex-1MnxO3 compounds for x = 0 and 0.1, which have been grown by the OFZ technique. The Neel temperature decreases from T-N1 = 691 K to T-N1 = 621 K, and the anomaly in AC susceptibility, related to spin reorientation, vanishes with Mn substitution. Low temperature heat capacity measurement for sample with x = 0.1 revealed that substitution of Mn for Fe shifts a Schottky-type anomaly at T-sh to higher temperatures. Another anomaly is generated by doping at T-max = 11 K. The anomaly is smeared out by magnetic field, confirming its magnetic origin.
T2  - Acta Physica Polonica A
T1  - Magnetic Properties of NdFe0.9Mn0.1O3
VL  - 126
IS  - 1
SP  - 306
EP  - 307
DO  - 10.12693/APhysPolA.126.306
ER  - 

@article{
author = "Zentkova, M. and Lazurova, J. and Kovač, Janez and Mihalik, M. and Mihalik, Jr., M. and Briancin, J. and Fitta, M. and Kusigerski, Vladan",
year = "2014",
abstract = "In our paper we study effect of Mn for Fe substitution on magnetic properties of NdFex-1MnxO3 compounds for x = 0 and 0.1, which have been grown by the OFZ technique. The Neel temperature decreases from T-N1 = 691 K to T-N1 = 621 K, and the anomaly in AC susceptibility, related to spin reorientation, vanishes with Mn substitution. Low temperature heat capacity measurement for sample with x = 0.1 revealed that substitution of Mn for Fe shifts a Schottky-type anomaly at T-sh to higher temperatures. Another anomaly is generated by doping at T-max = 11 K. The anomaly is smeared out by magnetic field, confirming its magnetic origin.",
journal = "Acta Physica Polonica A",
title = "Magnetic Properties of NdFe0.9Mn0.1O3",
volume = "126",
number = "1",
pages = "306-307",
doi = "10.12693/APhysPolA.126.306"
}

Zentkova, M., Lazurova, J., Kovač, J., Mihalik, M., Mihalik, Jr., M., Briancin, J., Fitta, M.,& Kusigerski, V.. (2014). Magnetic Properties of NdFe0.9Mn0.1O3. in Acta Physica Polonica A, 126(1), 306-307.
https://doi.org/10.12693/APhysPolA.126.306

Zentkova M, Lazurova J, Kovač J, Mihalik M, Mihalik JM, Briancin J, Fitta M, Kusigerski V. Magnetic Properties of NdFe0.9Mn0.1O3. in Acta Physica Polonica A. 2014;126(1):306-307.
doi:10.12693/APhysPolA.126.306 .

Zentkova, M., Lazurova, J., Kovač, Janez, Mihalik, M., Mihalik, Jr., M., Briancin, J., Fitta, M., Kusigerski, Vladan, "Magnetic Properties of NdFe0.9Mn0.1O3" in Acta Physica Polonica A, 126, no. 1 (2014):306-307,
https://doi.org/10.12693/APhysPolA.126.306 . .