Stojadinović, Stevan

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  • Stojadinović, Stevan (10)

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Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry

Rajić, Vladimir; Stojković Simatović, Ivana; Veselinović, Ljiljana; Belošević Čavor, Jelena; Novaković, Mirjana; Popović, Maja; Škapin, Srečo Davor; Mojović, Miloš; Stojadinović, Stevan; Rac, Vladislav; Janković Častvan, Ivona; Marković, Smilja

(Royal Society of Chemistry, 2020)

TY  - JOUR
AU  - Rajić, Vladimir
AU  - Stojković Simatović, Ivana
AU  - Veselinović, Ljiljana
AU  - Belošević Čavor, Jelena
AU  - Novaković, Mirjana
AU  - Popović, Maja
AU  - Škapin, Srečo Davor
AU  - Mojović, Miloš
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Janković Častvan, Ivona
AU  - Marković, Smilja
PY  - 2020
AB  - Eco-friendly and rapid microwave processing of a precipitate was used to produce Fe-doped zinc oxide (Zn1−xFexO, x = 0, 0.05, 0.1, 0.15 and 0.20; ZnO:Fe) nanoparticles, which were tested as catalysts toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in a moderately alkaline solution. The phase composition, crystal structure, morphology, textural properties, surface chemistry, optical properties and band structure were examined to comprehend the influence of Zn2+ partial substitution with Fe3+ on the catalytic activity of ZnO:Fe. Linear sweep voltammetry showed an improved catalytic activity of ZnO:5Fe toward the ORR, compared to pure ZnO, while with increased amounts of the Fe-dopant the activity decreased. The improvement was suggested by a more positive onset potential (0.394 V vs. RHE), current density (0.231 mA cm−2 at 0.150 V vs. RHE), and faster kinetics (Tafel slope, b = 248 mV dec−1), and it may be due to the synergistic effect of (1) a sufficient amount of surface oxygen vacancies, and (2) a certain amount of plate-like particles composed of crystallites with well developed (0001) and (000) facets. Quite the contrary, the OER study showed that the introduction of Fe3+ ions into the ZnO crystal structure resulted in enhanced catalytic activity of all ZnO:Fe samples, compared to pure ZnO, probably due to the modified binding energy and an optimized band structure. With the maximal current density of 1.066 mA cm−2 at 2.216 V vs. RHE, an onset potential of 1.856 V vs. RHE, and the smallest potential difference between the OER and ORR (ΔE = 1.58 V), ZnO:10Fe may be considered a promising bifunctional catalyst toward the OER/ORR in moderately alkaline solution. This study demonstrates that the electrocatalytic activity of ZnO:Fe strongly depends on the defect chemistry and consequently the band structure. Along with providing fundamental insight into the electrocatalytic activity of ZnO:Fe, the study also indicates an optimal stoichiometry for enhanced bifunctional activity toward the OER/ORR, compared to pure ZnO.
PB  - Royal Society of Chemistry
T2  - Physical Chemistry Chemical Physics
T1  - Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry
SP  - 22078
EP  - 22095
VL  - 22
IS  - 38
DO  - 10.1039/D0CP03377D
ER  - 
@article{
author = "Rajić, Vladimir and Stojković Simatović, Ivana and Veselinović, Ljiljana and Belošević Čavor, Jelena and Novaković, Mirjana and Popović, Maja and Škapin, Srečo Davor and Mojović, Miloš and Stojadinović, Stevan and Rac, Vladislav and Janković Častvan, Ivona and Marković, Smilja",
year = "2020",
abstract = "Eco-friendly and rapid microwave processing of a precipitate was used to produce Fe-doped zinc oxide (Zn1−xFexO, x = 0, 0.05, 0.1, 0.15 and 0.20; ZnO:Fe) nanoparticles, which were tested as catalysts toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in a moderately alkaline solution. The phase composition, crystal structure, morphology, textural properties, surface chemistry, optical properties and band structure were examined to comprehend the influence of Zn2+ partial substitution with Fe3+ on the catalytic activity of ZnO:Fe. Linear sweep voltammetry showed an improved catalytic activity of ZnO:5Fe toward the ORR, compared to pure ZnO, while with increased amounts of the Fe-dopant the activity decreased. The improvement was suggested by a more positive onset potential (0.394 V vs. RHE), current density (0.231 mA cm−2 at 0.150 V vs. RHE), and faster kinetics (Tafel slope, b = 248 mV dec−1), and it may be due to the synergistic effect of (1) a sufficient amount of surface oxygen vacancies, and (2) a certain amount of plate-like particles composed of crystallites with well developed (0001) and (000) facets. Quite the contrary, the OER study showed that the introduction of Fe3+ ions into the ZnO crystal structure resulted in enhanced catalytic activity of all ZnO:Fe samples, compared to pure ZnO, probably due to the modified binding energy and an optimized band structure. With the maximal current density of 1.066 mA cm−2 at 2.216 V vs. RHE, an onset potential of 1.856 V vs. RHE, and the smallest potential difference between the OER and ORR (ΔE = 1.58 V), ZnO:10Fe may be considered a promising bifunctional catalyst toward the OER/ORR in moderately alkaline solution. This study demonstrates that the electrocatalytic activity of ZnO:Fe strongly depends on the defect chemistry and consequently the band structure. Along with providing fundamental insight into the electrocatalytic activity of ZnO:Fe, the study also indicates an optimal stoichiometry for enhanced bifunctional activity toward the OER/ORR, compared to pure ZnO.",
publisher = "Royal Society of Chemistry",
journal = "Physical Chemistry Chemical Physics",
title = "Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry",
pages = "22078-22095",
volume = "22",
number = "38",
doi = "10.1039/D0CP03377D"
}
Rajić, V., Stojković Simatović, I., Veselinović, L., Belošević Čavor, J., Novaković, M., Popović, M., Škapin, S. D., Mojović, M., Stojadinović, S., Rac, V., Janković Častvan, I.,& Marković, S. (2020). Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry.
Physical Chemistry Chemical Physics
Royal Society of Chemistry., 22(38), 22078-22095.
https://doi.org/10.1039/D0CP03377D
Rajić V, Stojković Simatović I, Veselinović L, Belošević Čavor J, Novaković M, Popović M, Škapin SD, Mojović M, Stojadinović S, Rac V, Janković Častvan I, Marković S. Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry. Physical Chemistry Chemical Physics. 2020;22(38):22078-22095.
doi:10.1039/D0CP03377D.
Rajić Vladimir, Stojković Simatović Ivana, Veselinović Ljiljana, Belošević Čavor Jelena, Novaković Mirjana, Popović Maja, Škapin Srečo Davor, Mojović Miloš, Stojadinović Stevan, Rac Vladislav, Janković Častvan Ivona, Marković Smilja, "Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry" Physical Chemistry Chemical Physics, 22, no. 38 (2020):22078-22095,
https://doi.org/10.1039/D0CP03377D .

Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry

Rajić, Vladimir; Stojković Simatović, Ivana; Veselinović, Ljiljana; Belošević Čavor, Jelena; Novaković, Mirjana; Popović, Maja; Škapin, Srečo Davor; Mojović, Miloš; Stojadinović, Stevan; Rac, Vladislav; Janković Častvan, Ivona; Marković, Smilja

(Royal Society of Chemistry, 2020)

TY  - JOUR
AU  - Rajić, Vladimir
AU  - Stojković Simatović, Ivana
AU  - Veselinović, Ljiljana
AU  - Belošević Čavor, Jelena
AU  - Novaković, Mirjana
AU  - Popović, Maja
AU  - Škapin, Srečo Davor
AU  - Mojović, Miloš
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Janković Častvan, Ivona
AU  - Marković, Smilja
PY  - 2020
AB  - Eco-friendly and rapid microwave processing of a precipitate was used to produce Fe-doped zinc oxide (Zn1−xFexO, x = 0, 0.05, 0.1, 0.15 and 0.20; ZnO:Fe) nanoparticles, which were tested as catalysts toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in a moderately alkaline solution. The phase composition, crystal structure, morphology, textural properties, surface chemistry, optical properties and band structure were examined to comprehend the influence of Zn2+ partial substitution with Fe3+ on the catalytic activity of ZnO:Fe. Linear sweep voltammetry showed an improved catalytic activity of ZnO:5Fe toward the ORR, compared to pure ZnO, while with increased amounts of the Fe-dopant the activity decreased. The improvement was suggested by a more positive onset potential (0.394 V vs. RHE), current density (0.231 mA cm−2 at 0.150 V vs. RHE), and faster kinetics (Tafel slope, b = 248 mV dec−1), and it may be due to the synergistic effect of (1) a sufficient amount of surface oxygen vacancies, and (2) a certain amount of plate-like particles composed of crystallites with well developed (0001) and (000) facets. Quite the contrary, the OER study showed that the introduction of Fe3+ ions into the ZnO crystal structure resulted in enhanced catalytic activity of all ZnO:Fe samples, compared to pure ZnO, probably due to the modified binding energy and an optimized band structure. With the maximal current density of 1.066 mA cm−2 at 2.216 V vs. RHE, an onset potential of 1.856 V vs. RHE, and the smallest potential difference between the OER and ORR (ΔE = 1.58 V), ZnO:10Fe may be considered a promising bifunctional catalyst toward the OER/ORR in moderately alkaline solution. This study demonstrates that the electrocatalytic activity of ZnO:Fe strongly depends on the defect chemistry and consequently the band structure. Along with providing fundamental insight into the electrocatalytic activity of ZnO:Fe, the study also indicates an optimal stoichiometry for enhanced bifunctional activity toward the OER/ORR, compared to pure ZnO.
PB  - Royal Society of Chemistry
T2  - Physical Chemistry Chemical Physics
T1  - Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry
SP  - 22078
EP  - 22095
VL  - 22
IS  - 38
DO  - 10.1039/D0CP03377D
ER  - 
@article{
author = "Rajić, Vladimir and Stojković Simatović, Ivana and Veselinović, Ljiljana and Belošević Čavor, Jelena and Novaković, Mirjana and Popović, Maja and Škapin, Srečo Davor and Mojović, Miloš and Stojadinović, Stevan and Rac, Vladislav and Janković Častvan, Ivona and Marković, Smilja",
year = "2020",
abstract = "Eco-friendly and rapid microwave processing of a precipitate was used to produce Fe-doped zinc oxide (Zn1−xFexO, x = 0, 0.05, 0.1, 0.15 and 0.20; ZnO:Fe) nanoparticles, which were tested as catalysts toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in a moderately alkaline solution. The phase composition, crystal structure, morphology, textural properties, surface chemistry, optical properties and band structure were examined to comprehend the influence of Zn2+ partial substitution with Fe3+ on the catalytic activity of ZnO:Fe. Linear sweep voltammetry showed an improved catalytic activity of ZnO:5Fe toward the ORR, compared to pure ZnO, while with increased amounts of the Fe-dopant the activity decreased. The improvement was suggested by a more positive onset potential (0.394 V vs. RHE), current density (0.231 mA cm−2 at 0.150 V vs. RHE), and faster kinetics (Tafel slope, b = 248 mV dec−1), and it may be due to the synergistic effect of (1) a sufficient amount of surface oxygen vacancies, and (2) a certain amount of plate-like particles composed of crystallites with well developed (0001) and (000) facets. Quite the contrary, the OER study showed that the introduction of Fe3+ ions into the ZnO crystal structure resulted in enhanced catalytic activity of all ZnO:Fe samples, compared to pure ZnO, probably due to the modified binding energy and an optimized band structure. With the maximal current density of 1.066 mA cm−2 at 2.216 V vs. RHE, an onset potential of 1.856 V vs. RHE, and the smallest potential difference between the OER and ORR (ΔE = 1.58 V), ZnO:10Fe may be considered a promising bifunctional catalyst toward the OER/ORR in moderately alkaline solution. This study demonstrates that the electrocatalytic activity of ZnO:Fe strongly depends on the defect chemistry and consequently the band structure. Along with providing fundamental insight into the electrocatalytic activity of ZnO:Fe, the study also indicates an optimal stoichiometry for enhanced bifunctional activity toward the OER/ORR, compared to pure ZnO.",
publisher = "Royal Society of Chemistry",
journal = "Physical Chemistry Chemical Physics",
title = "Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry",
pages = "22078-22095",
volume = "22",
number = "38",
doi = "10.1039/D0CP03377D"
}
Rajić, V., Stojković Simatović, I., Veselinović, L., Belošević Čavor, J., Novaković, M., Popović, M., Škapin, S. D., Mojović, M., Stojadinović, S., Rac, V., Janković Častvan, I.,& Marković, S. (2020). Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry.
Physical Chemistry Chemical Physics
Royal Society of Chemistry., 22(38), 22078-22095.
https://doi.org/10.1039/D0CP03377D
Rajić V, Stojković Simatović I, Veselinović L, Belošević Čavor J, Novaković M, Popović M, Škapin SD, Mojović M, Stojadinović S, Rac V, Janković Častvan I, Marković S. Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry. Physical Chemistry Chemical Physics. 2020;22(38):22078-22095.
doi:10.1039/D0CP03377D.
Rajić Vladimir, Stojković Simatović Ivana, Veselinović Ljiljana, Belošević Čavor Jelena, Novaković Mirjana, Popović Maja, Škapin Srečo Davor, Mojović Miloš, Stojadinović Stevan, Rac Vladislav, Janković Častvan Ivona, Marković Smilja, "Bifunctional catalytic activity of Zn1−xFexO toward the OER/ORR: seeking an optimal stoichiometry" Physical Chemistry Chemical Physics, 22, no. 38 (2020):22078-22095,
https://doi.org/10.1039/D0CP03377D .

Surfactant-assisted microwave processing of ZnO particles: a simple way for designing the surface-to-bulk defect ratio and improving photo(electro)catalytic properties

Marković, Smilja; Stojković Simatović, Ivana; Ahmetović, Sanita; Veselinović, Ljiljana; Stojadinović, Stevan; Rac, Vladislav; Škapin, Srečo Davor; Bajuk Bogdanović, Danica; Janković Častvan, Ivona; Uskoković, Dragan

(Royal Society of Chemistry, 2019)

TY  - JOUR
AU  - Marković, Smilja
AU  - Stojković Simatović, Ivana
AU  - Ahmetović, Sanita
AU  - Veselinović, Ljiljana
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Škapin, Srečo Davor
AU  - Bajuk Bogdanović, Danica
AU  - Janković Častvan, Ivona
AU  - Uskoković, Dragan
PY  - 2019
AB  - ZnO nanopowders were produced using microwave processing of a precipitate and applied as a photoanode for photoelectrochemical water splitting. Two different surfactants, cetyltrimethylammonium bromide (CTAB) as the cationic and Pluronic F127 as the non-ionic one, were employed to in situ adjust the surface-to-bulk defect ratio in the ZnO crystal structure and further to modify the photo(electro)catalytic activity of the ZnO photoanode. The crystal structure, morphological, textural, optical and photo(electro)catalytic properties of ZnO particles were studied in detail to explain the profound effects of the surfactants on the photoanode activity. The ZnO/CTAB photoanode displayed the highest photocurrent density of 27 mA g−1, compared to ZnO (10.4 mA g−1) and ZnO/F127 photoanodes (20 mA g−1) at 1.5 V vs. SCE in 0.1 M Na2SO4 under visible illumination of 90 mW cm−2. A significant shift of the overpotential toward lower values was also observed when photoanodes were illuminated. The highest shift of the overpotential, from 1.296 to 0.248 V vs. SCE, was recorded when the ZnO/CTAB photanode was illuminated. The ZnO/CTAB photoanode provides efficient charge transfer across the electrode/electrolyte interface, with a longer lifetime of photogenerated electron–hole pairs and reduced possibility of charge recombination. The photoconversion efficiency was improved from 1.4% for ZnO and 0.9% for ZnO/F127 to 4.2% for ZnO/CTAB at 0.510 mV. A simple procedure for the synthesis of ZnO particles with improved photo(electro)catalytic properties was established and it was found that even a small amount of CTAB used during processing of ZnO increases the surface-to-bulk defect ratio. Optimization of the surface-to-bulk defect ratio in ZnO materials enables increase of the absorption capacity for visible light, rendering of the recombination rate of the photogenerated pair, as well as increase of both the photocurrent density and photoconversion efficiency.
PB  - Royal Society of Chemistry
T2  - RSC Advances
T1  - Surfactant-assisted microwave processing of ZnO particles: a simple way for designing the surface-to-bulk defect ratio and improving photo(electro)catalytic properties
SP  - 17165
EP  - 17178
VL  - 9
IS  - 30
DO  - 10.1039/C9RA02553G
UR  - https://hdl.handle.net/21.15107/rcub_dais_6272
ER  - 
@article{
author = "Marković, Smilja and Stojković Simatović, Ivana and Ahmetović, Sanita and Veselinović, Ljiljana and Stojadinović, Stevan and Rac, Vladislav and Škapin, Srečo Davor and Bajuk Bogdanović, Danica and Janković Častvan, Ivona and Uskoković, Dragan",
year = "2019",
abstract = "ZnO nanopowders were produced using microwave processing of a precipitate and applied as a photoanode for photoelectrochemical water splitting. Two different surfactants, cetyltrimethylammonium bromide (CTAB) as the cationic and Pluronic F127 as the non-ionic one, were employed to in situ adjust the surface-to-bulk defect ratio in the ZnO crystal structure and further to modify the photo(electro)catalytic activity of the ZnO photoanode. The crystal structure, morphological, textural, optical and photo(electro)catalytic properties of ZnO particles were studied in detail to explain the profound effects of the surfactants on the photoanode activity. The ZnO/CTAB photoanode displayed the highest photocurrent density of 27 mA g−1, compared to ZnO (10.4 mA g−1) and ZnO/F127 photoanodes (20 mA g−1) at 1.5 V vs. SCE in 0.1 M Na2SO4 under visible illumination of 90 mW cm−2. A significant shift of the overpotential toward lower values was also observed when photoanodes were illuminated. The highest shift of the overpotential, from 1.296 to 0.248 V vs. SCE, was recorded when the ZnO/CTAB photanode was illuminated. The ZnO/CTAB photoanode provides efficient charge transfer across the electrode/electrolyte interface, with a longer lifetime of photogenerated electron–hole pairs and reduced possibility of charge recombination. The photoconversion efficiency was improved from 1.4% for ZnO and 0.9% for ZnO/F127 to 4.2% for ZnO/CTAB at 0.510 mV. A simple procedure for the synthesis of ZnO particles with improved photo(electro)catalytic properties was established and it was found that even a small amount of CTAB used during processing of ZnO increases the surface-to-bulk defect ratio. Optimization of the surface-to-bulk defect ratio in ZnO materials enables increase of the absorption capacity for visible light, rendering of the recombination rate of the photogenerated pair, as well as increase of both the photocurrent density and photoconversion efficiency.",
publisher = "Royal Society of Chemistry",
journal = "RSC Advances",
title = "Surfactant-assisted microwave processing of ZnO particles: a simple way for designing the surface-to-bulk defect ratio and improving photo(electro)catalytic properties",
pages = "17165-17178",
volume = "9",
number = "30",
doi = "10.1039/C9RA02553G",
url = "https://hdl.handle.net/21.15107/rcub_dais_6272"
}
Marković, S., Stojković Simatović, I., Ahmetović, S., Veselinović, L., Stojadinović, S., Rac, V., Škapin, S. D., Bajuk Bogdanović, D., Janković Častvan, I.,& Uskoković, D. (2019). Surfactant-assisted microwave processing of ZnO particles: a simple way for designing the surface-to-bulk defect ratio and improving photo(electro)catalytic properties.
RSC Advances
Royal Society of Chemistry., 9(30), 17165-17178.
https://doi.org/10.1039/C9RA02553G
Marković S, Stojković Simatović I, Ahmetović S, Veselinović L, Stojadinović S, Rac V, Škapin SD, Bajuk Bogdanović D, Janković Častvan I, Uskoković D. Surfactant-assisted microwave processing of ZnO particles: a simple way for designing the surface-to-bulk defect ratio and improving photo(electro)catalytic properties. RSC Advances. 2019;9(30):17165-17178.
doi:10.1039/C9RA02553G.
Marković Smilja, Stojković Simatović Ivana, Ahmetović Sanita, Veselinović Ljiljana, Stojadinović Stevan, Rac Vladislav, Škapin Srečo Davor, Bajuk Bogdanović Danica, Janković Častvan Ivona, Uskoković Dragan, "Surfactant-assisted microwave processing of ZnO particles: a simple way for designing the surface-to-bulk defect ratio and improving photo(electro)catalytic properties" RSC Advances, 9, no. 30 (2019):17165-17178,
https://doi.org/10.1039/C9RA02553G .
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Point defect-enhanced optical and photoelectrochemical water splitting activity of nanostructured Zn1-xFeyO(1-x+1.5y)

Marković, Smilja; Rajić, Vladimir B.; Stojković Simatović, Ivana; Veselinović, Ljiljana; Belošević Čavor, Jelena; Ivanovski, Valentin N.; Novaković, Mirjana; Škapin, Srečo Davor; Stojadinović, Stevan; Rac, Vladislav; Uskoković, Dragan

(Belgrade : Materials Research Society of Serbia, 2019)

TY  - CONF
AU  - Marković, Smilja
AU  - Rajić, Vladimir B.
AU  - Stojković Simatović, Ivana
AU  - Veselinović, Ljiljana
AU  - Belošević Čavor, Jelena
AU  - Ivanovski, Valentin N.
AU  - Novaković, Mirjana
AU  - Škapin, Srečo Davor
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Uskoković, Dragan
PY  - 2019
AB  - Even has been under study since 1935, zinc oxide (ZnO) based materials still attract a huge scientific attention. Owing to a wide band gap energy (3.37 eV at room temperature) and a large exciton binding energy (60 meV) ZnO has a variety of application, e.g. in electronics, optoelectronics, spintronics and photocatalysis. Besides, it has been shown that zinc oxide-based materials have a great potential as photoelectrocatalysts in the processes of water splitting, yielding an increased both photocurrent density and photoconversion efficiency. However, with a band gap energy of 3.37 eV, ZnO is restricted to absorb UV light only. This restriction can be overcome by modifying optical properties of zinc oxide particles. During the years different approaches have been applied to modify the visible light photocatalytic activity of ZnO materials, for example: (1) metal and nonmetal ion doping, (2) hydrogenation, (3) the incorporation of crystalline defects in the form of vacancies and interstitials, (4) the modification of particles morphology and surface topology, etc.
In this study we employed 3d metal ion substitution to improve visible light-driven photoactivity of zinc oxide particles. We investigated the influence of Fe concentration in Zn1-xFeyO(1-x+1.5y) nanoparticles on crystal structure, textural, optical and photoelectrocatalytic properties. Zn1-xFeyO(1-x+1.5y) nanoparticles with nominally 5, 10, 15 and 20 at.% of Fe ions were synthesized by microwave processing of a precipitate. The crystal structure and phase purity of the samples were investigated by X-ray diffraction, Raman and ATR-FTIR spectroscopy. Mössbauer spectroscopy was carried out to clarify the valence state of the iron ions in the ZnO crystal structure. Effects of the iron ions concentration on particles morphology and texture properties were observed with field emission scanning electron microscopy (FE–SEM), transmission electron microscopy (TEM) with elemental mapping, and nitrogen adsorption–desorption isotherm, respectively. The optical properties were studied using UV–Vis diffuse reflectance and photoluminescence (PL) spectroscopy. Photoelectrochemical activity of the Zn1-xFeyO(1-x+1.5y) samples as anode material was evaluated by linear sweep voltammetry in Na2SO4 electrolyte; the oxygen evolution kinetics were determined and compared. In addition, a series of first principles calculations were performed to address the influence of the iron concentration on the electronic structure of Zn1-xFeyO(1-x+1.5y) samples.
PB  - Belgrade : Materials Research Society of Serbia
C3  - Programme and The Book of abstracts / Twenty-first Annual Conference YUCOMAT 2019 & Eleventh World Round Table Conference on Sintering WRTCS 2019, Herceg Novi, Montenegro, September 2-6, 2019
T1  - Point defect-enhanced optical and photoelectrochemical water splitting activity of nanostructured Zn1-xFeyO(1-x+1.5y)
SP  - 54
EP  - 54
UR  - https://hdl.handle.net/21.15107/rcub_dais_6677
ER  - 
@conference{
author = "Marković, Smilja and Rajić, Vladimir B. and Stojković Simatović, Ivana and Veselinović, Ljiljana and Belošević Čavor, Jelena and Ivanovski, Valentin N. and Novaković, Mirjana and Škapin, Srečo Davor and Stojadinović, Stevan and Rac, Vladislav and Uskoković, Dragan",
year = "2019",
abstract = "Even has been under study since 1935, zinc oxide (ZnO) based materials still attract a huge scientific attention. Owing to a wide band gap energy (3.37 eV at room temperature) and a large exciton binding energy (60 meV) ZnO has a variety of application, e.g. in electronics, optoelectronics, spintronics and photocatalysis. Besides, it has been shown that zinc oxide-based materials have a great potential as photoelectrocatalysts in the processes of water splitting, yielding an increased both photocurrent density and photoconversion efficiency. However, with a band gap energy of 3.37 eV, ZnO is restricted to absorb UV light only. This restriction can be overcome by modifying optical properties of zinc oxide particles. During the years different approaches have been applied to modify the visible light photocatalytic activity of ZnO materials, for example: (1) metal and nonmetal ion doping, (2) hydrogenation, (3) the incorporation of crystalline defects in the form of vacancies and interstitials, (4) the modification of particles morphology and surface topology, etc.
In this study we employed 3d metal ion substitution to improve visible light-driven photoactivity of zinc oxide particles. We investigated the influence of Fe concentration in Zn1-xFeyO(1-x+1.5y) nanoparticles on crystal structure, textural, optical and photoelectrocatalytic properties. Zn1-xFeyO(1-x+1.5y) nanoparticles with nominally 5, 10, 15 and 20 at.% of Fe ions were synthesized by microwave processing of a precipitate. The crystal structure and phase purity of the samples were investigated by X-ray diffraction, Raman and ATR-FTIR spectroscopy. Mössbauer spectroscopy was carried out to clarify the valence state of the iron ions in the ZnO crystal structure. Effects of the iron ions concentration on particles morphology and texture properties were observed with field emission scanning electron microscopy (FE–SEM), transmission electron microscopy (TEM) with elemental mapping, and nitrogen adsorption–desorption isotherm, respectively. The optical properties were studied using UV–Vis diffuse reflectance and photoluminescence (PL) spectroscopy. Photoelectrochemical activity of the Zn1-xFeyO(1-x+1.5y) samples as anode material was evaluated by linear sweep voltammetry in Na2SO4 electrolyte; the oxygen evolution kinetics were determined and compared. In addition, a series of first principles calculations were performed to address the influence of the iron concentration on the electronic structure of Zn1-xFeyO(1-x+1.5y) samples.",
publisher = "Belgrade : Materials Research Society of Serbia",
journal = "Programme and The Book of abstracts / Twenty-first Annual Conference YUCOMAT 2019 & Eleventh World Round Table Conference on Sintering WRTCS 2019, Herceg Novi, Montenegro, September 2-6, 2019",
title = "Point defect-enhanced optical and photoelectrochemical water splitting activity of nanostructured Zn1-xFeyO(1-x+1.5y)",
pages = "54-54",
url = "https://hdl.handle.net/21.15107/rcub_dais_6677"
}
Marković, S., Rajić, V. B., Stojković Simatović, I., Veselinović, L., Belošević Čavor, J., Ivanovski, V. N., Novaković, M., Škapin, S. D., Stojadinović, S., Rac, V.,& Uskoković, D. (2019). Point defect-enhanced optical and photoelectrochemical water splitting activity of nanostructured Zn1-xFeyO(1-x+1.5y).
Programme and The Book of abstracts / Twenty-first Annual Conference YUCOMAT 2019 & Eleventh World Round Table Conference on Sintering WRTCS 2019, Herceg Novi, Montenegro, September 2-6, 2019
Belgrade : Materials Research Society of Serbia., 54-54.
Marković S, Rajić VB, Stojković Simatović I, Veselinović L, Belošević Čavor J, Ivanovski VN, Novaković M, Škapin SD, Stojadinović S, Rac V, Uskoković D. Point defect-enhanced optical and photoelectrochemical water splitting activity of nanostructured Zn1-xFeyO(1-x+1.5y). Programme and The Book of abstracts / Twenty-first Annual Conference YUCOMAT 2019 & Eleventh World Round Table Conference on Sintering WRTCS 2019, Herceg Novi, Montenegro, September 2-6, 2019. 2019;:54-54.
Marković Smilja, Rajić Vladimir B., Stojković Simatović Ivana, Veselinović Ljiljana, Belošević Čavor Jelena, Ivanovski Valentin N., Novaković Mirjana, Škapin Srečo Davor, Stojadinović Stevan, Rac Vladislav, Uskoković Dragan, "Point defect-enhanced optical and photoelectrochemical water splitting activity of nanostructured Zn1-xFeyO(1-x+1.5y)" Programme and The Book of abstracts / Twenty-first Annual Conference YUCOMAT 2019 & Eleventh World Round Table Conference on Sintering WRTCS 2019, Herceg Novi, Montenegro, September 2-6, 2019 (2019):54-54

Structural, photocatalytic and photoelectrochemical characteristics of ZnO nanoparticles synthesized by a glycine-nitrate process

Dojčinović, Milena; Stojković Simatović, Ivana; Marković, Smilja; Janković Častvan, Ivona; Bajuk Bogdanović, Danica; Stojadinović, Stevan; Rac, Vladislav; Nikolić, Maria Vesna

(Budapest : [s. n.], 2019)

TY  - CONF
AU  - Dojčinović, Milena
AU  - Stojković Simatović, Ivana
AU  - Marković, Smilja
AU  - Janković Častvan, Ivona
AU  - Bajuk Bogdanović, Danica
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Nikolić, Maria Vesna
PY  - 2019
AB  - Zinc oxide is a semiconductor material which still, after a century of scientific research, shows great potential in modern day utilisements such as heterogenous photocatalysis of organic pollutants and as a photoanode material for efficient water splitting and oxygen generation. In this work zinc oxide was synthesized by a glycine-nitrate combustion process, which is a cheap, simple and efficient method for synthesizing transition metal oxides. The obtained powder was calcined at 400 and 500 °C and samples were characterized in detail using X-ray powder diffraction (XRPD), Fourier-trasform infrared spectroscopy (FTIR), Raman spectroscopy, field emission scanning electron microscopy (FESEM), photoluminescence spectroscopy (PL) and UV-Vis diffuse reflectance spectroscopy (DRS). Photoelectrocatalytic properties were investigated via electrochemical methods: linear voltammetry (LV), chronoamperometry (CA) and impedance spectroscopy (EIS). The results show that the obtained samples are nanocrystalline wurtzite zinc oxide with no impurities, with average particle diameters of 33 nm (annealed at 400 °C) and 48 nm (annealed at 500 °C). Both samples show significant amounts of various crystal deffects. The determined zinc oxide band gap was lower than the band gap of bulk zinc oxide. Photoelectrochemical measurements revealed that this material is photostable and reactive to light. Water oxidation is enhanced by exposing the light. Finally, photocatalytic properties were tested via determining kinetic parameters of organic pollutant decomposition. Both samples showed excellent photocatalytic activity by decomposing methylene blue and phenol.
PB  - Budapest : [s. n.]
C3  - Abstracts / International Workshop on Woman in Ceramic Science (WoCeram2019), April 7-9, 2019/ Budapest, Hungary, Novotel Danube Budapest
T1  - Structural, photocatalytic and photoelectrochemical characteristics of ZnO nanoparticles synthesized by a glycine-nitrate process
SP  - 16
EP  - 16
ER  - 
@conference{
author = "Dojčinović, Milena and Stojković Simatović, Ivana and Marković, Smilja and Janković Častvan, Ivona and Bajuk Bogdanović, Danica and Stojadinović, Stevan and Rac, Vladislav and Nikolić, Maria Vesna",
year = "2019",
abstract = "Zinc oxide is a semiconductor material which still, after a century of scientific research, shows great potential in modern day utilisements such as heterogenous photocatalysis of organic pollutants and as a photoanode material for efficient water splitting and oxygen generation. In this work zinc oxide was synthesized by a glycine-nitrate combustion process, which is a cheap, simple and efficient method for synthesizing transition metal oxides. The obtained powder was calcined at 400 and 500 °C and samples were characterized in detail using X-ray powder diffraction (XRPD), Fourier-trasform infrared spectroscopy (FTIR), Raman spectroscopy, field emission scanning electron microscopy (FESEM), photoluminescence spectroscopy (PL) and UV-Vis diffuse reflectance spectroscopy (DRS). Photoelectrocatalytic properties were investigated via electrochemical methods: linear voltammetry (LV), chronoamperometry (CA) and impedance spectroscopy (EIS). The results show that the obtained samples are nanocrystalline wurtzite zinc oxide with no impurities, with average particle diameters of 33 nm (annealed at 400 °C) and 48 nm (annealed at 500 °C). Both samples show significant amounts of various crystal deffects. The determined zinc oxide band gap was lower than the band gap of bulk zinc oxide. Photoelectrochemical measurements revealed that this material is photostable and reactive to light. Water oxidation is enhanced by exposing the light. Finally, photocatalytic properties were tested via determining kinetic parameters of organic pollutant decomposition. Both samples showed excellent photocatalytic activity by decomposing methylene blue and phenol.",
publisher = "Budapest : [s. n.]",
journal = "Abstracts / International Workshop on Woman in Ceramic Science (WoCeram2019), April 7-9, 2019/ Budapest, Hungary, Novotel Danube Budapest",
title = "Structural, photocatalytic and photoelectrochemical characteristics of ZnO nanoparticles synthesized by a glycine-nitrate process",
pages = "16-16"
}
Dojčinović, M., Stojković Simatović, I., Marković, S., Janković Častvan, I., Bajuk Bogdanović, D., Stojadinović, S., Rac, V.,& Nikolić, M. V. (2019). Structural, photocatalytic and photoelectrochemical characteristics of ZnO nanoparticles synthesized by a glycine-nitrate process.
Abstracts / International Workshop on Woman in Ceramic Science (WoCeram2019), April 7-9, 2019/ Budapest, Hungary, Novotel Danube Budapest
Budapest : [s. n.]., 16-16.
Dojčinović M, Stojković Simatović I, Marković S, Janković Častvan I, Bajuk Bogdanović D, Stojadinović S, Rac V, Nikolić MV. Structural, photocatalytic and photoelectrochemical characteristics of ZnO nanoparticles synthesized by a glycine-nitrate process. Abstracts / International Workshop on Woman in Ceramic Science (WoCeram2019), April 7-9, 2019/ Budapest, Hungary, Novotel Danube Budapest. 2019;:16-16.
Dojčinović Milena, Stojković Simatović Ivana, Marković Smilja, Janković Častvan Ivona, Bajuk Bogdanović Danica, Stojadinović Stevan, Rac Vladislav, Nikolić Maria Vesna, "Structural, photocatalytic and photoelectrochemical characteristics of ZnO nanoparticles synthesized by a glycine-nitrate process" Abstracts / International Workshop on Woman in Ceramic Science (WoCeram2019), April 7-9, 2019/ Budapest, Hungary, Novotel Danube Budapest (2019):16-16

CTAB- and pluronic F-127-assisted microwave processing of ZnO particles with modified morphology and optical properties

Marković, Smilja; Stojković Simatović, Ivana; Ahmetović, Sanita; Veselinović, Ljiljana; Stojadinović, Stevan; Rac, Vladislav; Škapin, Srečo Davor; Uskoković, Dragan

(Belgrade : Materials Research Society of Serbia, 2018)

TY  - CONF
AU  - Marković, Smilja
AU  - Stojković Simatović, Ivana
AU  - Ahmetović, Sanita
AU  - Veselinović, Ljiljana
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Škapin, Srečo Davor
AU  - Uskoković, Dragan
PY  - 2018
AB  - Zinc oxide-based materials have a great potential to be applied as photocatalysts in the processes of removal of organic and biological pollutants from drinking and wastewaters. A major drawback of ZnO as visible-light absorber is a band energy gap of 3.37 eV, which restricts the material to absorb UV light only. This drawback can be overcame by modifying the optical absorption properties of zinc oxide particles. Different approaches have been applied to modify the visible light photocatalytic activity of ZnO materials: (1) metal and nonmetal ion doping, (2) hydrogenation, (3) the incorporation of crystalline defects in the form of vacancies and interstitials, (4) the modification of particles morphology and surface topology, etc. In this study we investigated the influence of different surfactants on the morphology, optical properties and functionality of ZnO particles. Two different surfactants were employed during microwave processing of ZnO particles, cetyltrimethylammonium bromide (CTAB) as cationic and Pluronic F-127 as non-ionic one. The crystal structure and phase purity of the ZnO particles were determined by X-ray diffraction and Raman spectroscopy. Effects of the surfactants on particles morphology and texture properties were observed with field emission scanning electron microscopy (FE–SEM) and nitrogen adsorption–desorption isotherm, respectively. The optical properties were studied using UV–Vis diffuse reflectance and photoluminescence (PL) spectroscopy. Functionality of ZnO particles was studied due to their photocatalytic and electrochemical activities. Photocatalytic activity was examined via decolorization of methylene blue under direct sunlight irradiation. Electrochemical behavior of the ZnO samples as anode material was evaluated by linear sweep voltammetry in Na2SO4 electrolyte; the oxygen evolution kinetics were determined and compared.
PB  - Belgrade : Materials Research Society of Serbia
C3  - Programme and The Book of Abstracts / Twentieth Annual Conference YUCOMAT 2018, Herceg Novi, September 3-7, 2018
T1  - CTAB- and pluronic F-127-assisted microwave processing of ZnO particles with modified morphology and optical properties
SP  - 70
EP  - 70
UR  - https://hdl.handle.net/21.15107/rcub_dais_3664
ER  - 
@conference{
author = "Marković, Smilja and Stojković Simatović, Ivana and Ahmetović, Sanita and Veselinović, Ljiljana and Stojadinović, Stevan and Rac, Vladislav and Škapin, Srečo Davor and Uskoković, Dragan",
year = "2018",
abstract = "Zinc oxide-based materials have a great potential to be applied as photocatalysts in the processes of removal of organic and biological pollutants from drinking and wastewaters. A major drawback of ZnO as visible-light absorber is a band energy gap of 3.37 eV, which restricts the material to absorb UV light only. This drawback can be overcame by modifying the optical absorption properties of zinc oxide particles. Different approaches have been applied to modify the visible light photocatalytic activity of ZnO materials: (1) metal and nonmetal ion doping, (2) hydrogenation, (3) the incorporation of crystalline defects in the form of vacancies and interstitials, (4) the modification of particles morphology and surface topology, etc. In this study we investigated the influence of different surfactants on the morphology, optical properties and functionality of ZnO particles. Two different surfactants were employed during microwave processing of ZnO particles, cetyltrimethylammonium bromide (CTAB) as cationic and Pluronic F-127 as non-ionic one. The crystal structure and phase purity of the ZnO particles were determined by X-ray diffraction and Raman spectroscopy. Effects of the surfactants on particles morphology and texture properties were observed with field emission scanning electron microscopy (FE–SEM) and nitrogen adsorption–desorption isotherm, respectively. The optical properties were studied using UV–Vis diffuse reflectance and photoluminescence (PL) spectroscopy. Functionality of ZnO particles was studied due to their photocatalytic and electrochemical activities. Photocatalytic activity was examined via decolorization of methylene blue under direct sunlight irradiation. Electrochemical behavior of the ZnO samples as anode material was evaluated by linear sweep voltammetry in Na2SO4 electrolyte; the oxygen evolution kinetics were determined and compared.",
publisher = "Belgrade : Materials Research Society of Serbia",
journal = "Programme and The Book of Abstracts / Twentieth Annual Conference YUCOMAT 2018, Herceg Novi, September 3-7, 2018",
title = "CTAB- and pluronic F-127-assisted microwave processing of ZnO particles with modified morphology and optical properties",
pages = "70-70",
url = "https://hdl.handle.net/21.15107/rcub_dais_3664"
}
Marković, S., Stojković Simatović, I., Ahmetović, S., Veselinović, L., Stojadinović, S., Rac, V., Škapin, S. D.,& Uskoković, D. (2018). CTAB- and pluronic F-127-assisted microwave processing of ZnO particles with modified morphology and optical properties.
Programme and The Book of Abstracts / Twentieth Annual Conference YUCOMAT 2018, Herceg Novi, September 3-7, 2018
Belgrade : Materials Research Society of Serbia., 70-70.
Marković S, Stojković Simatović I, Ahmetović S, Veselinović L, Stojadinović S, Rac V, Škapin SD, Uskoković D. CTAB- and pluronic F-127-assisted microwave processing of ZnO particles with modified morphology and optical properties. Programme and The Book of Abstracts / Twentieth Annual Conference YUCOMAT 2018, Herceg Novi, September 3-7, 2018. 2018;:70-70.
Marković Smilja, Stojković Simatović Ivana, Ahmetović Sanita, Veselinović Ljiljana, Stojadinović Stevan, Rac Vladislav, Škapin Srečo Davor, Uskoković Dragan, "CTAB- and pluronic F-127-assisted microwave processing of ZnO particles with modified morphology and optical properties" Programme and The Book of Abstracts / Twentieth Annual Conference YUCOMAT 2018, Herceg Novi, September 3-7, 2018 (2018):70-70

Enhanced photo(electro)catalytic properties of ZnO particles synthesized by CTAB-assisted microwave processing

Marković, Smilja; Stojković Simatović, Ivana; Ahmetović, Sanita; Veselinović, Ljiljana; Stojadinović, Stevan; Rac, Vladislav; Škapin, Srečo Davor; Uskoković, Dragan

(Belgrade : Society of Physical Chemists of Serbia, 2018)

TY  - CONF
AU  - Marković, Smilja
AU  - Stojković Simatović, Ivana
AU  - Ahmetović, Sanita
AU  - Veselinović, Ljiljana
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Škapin, Srečo Davor
AU  - Uskoković, Dragan
PY  - 2018
AB  - ZnO/CTAB powder was prepared by microwave processing of a precipitate with the aid of cetyltrimethylammonium bromide (CTAB). The effects of CTAB on the crystal structure, morphology, optical and photo(electro)catalytic properties of ZnO particles were studied. The results showed that CTAB did not influenced crystal structure or phase purity of ZnO. However, even low concentration of CTAB vary particles morphology; cone-like particles were prepared by processing without CTAB, while a mixture of spheroidal and plate-like ZnO particles were produced when 0.001 M CTAB was used. It was found that synthesized ZnO powders have 0.10 eV lower band gap energy then bulk ZnO (3.37 eV). A high photocatalytic activity for decolorization of methylene blue water solution was established after 2 h of sunlight irradiation; efficiency was 100 and 67% for ZnO/CTAB and ZnO, respectively. Electrochemical test showed faster oxygen evolution kinetics when ZnO/CTAB was used as anode material. Enhanced photo(electro)catalytic activities of ZnO/CTAB particles are attributed to better absorption of visible light due to both, larger dimensions and surface sensitization by CTAB.
PB  - Belgrade : Society of Physical Chemists of Serbia
C3  - Physical Chemistry 2018 : proceedings. Vol. 1 / 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry, September 24-28, 2018, Belgrade
T1  - Enhanced photo(electro)catalytic properties of ZnO particles synthesized by CTAB-assisted microwave processing
SP  - 237
EP  - 240
UR  - https://hdl.handle.net/21.15107/rcub_dais_4561
ER  - 
@conference{
author = "Marković, Smilja and Stojković Simatović, Ivana and Ahmetović, Sanita and Veselinović, Ljiljana and Stojadinović, Stevan and Rac, Vladislav and Škapin, Srečo Davor and Uskoković, Dragan",
year = "2018",
abstract = "ZnO/CTAB powder was prepared by microwave processing of a precipitate with the aid of cetyltrimethylammonium bromide (CTAB). The effects of CTAB on the crystal structure, morphology, optical and photo(electro)catalytic properties of ZnO particles were studied. The results showed that CTAB did not influenced crystal structure or phase purity of ZnO. However, even low concentration of CTAB vary particles morphology; cone-like particles were prepared by processing without CTAB, while a mixture of spheroidal and plate-like ZnO particles were produced when 0.001 M CTAB was used. It was found that synthesized ZnO powders have 0.10 eV lower band gap energy then bulk ZnO (3.37 eV). A high photocatalytic activity for decolorization of methylene blue water solution was established after 2 h of sunlight irradiation; efficiency was 100 and 67% for ZnO/CTAB and ZnO, respectively. Electrochemical test showed faster oxygen evolution kinetics when ZnO/CTAB was used as anode material. Enhanced photo(electro)catalytic activities of ZnO/CTAB particles are attributed to better absorption of visible light due to both, larger dimensions and surface sensitization by CTAB.",
publisher = "Belgrade : Society of Physical Chemists of Serbia",
journal = "Physical Chemistry 2018 : proceedings. Vol. 1 / 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry, September 24-28, 2018, Belgrade",
title = "Enhanced photo(electro)catalytic properties of ZnO particles synthesized by CTAB-assisted microwave processing",
pages = "237-240",
url = "https://hdl.handle.net/21.15107/rcub_dais_4561"
}
Marković, S., Stojković Simatović, I., Ahmetović, S., Veselinović, L., Stojadinović, S., Rac, V., Škapin, S. D.,& Uskoković, D. (2018). Enhanced photo(electro)catalytic properties of ZnO particles synthesized by CTAB-assisted microwave processing.
Physical Chemistry 2018 : proceedings. Vol. 1 / 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry, September 24-28, 2018, Belgrade
Belgrade : Society of Physical Chemists of Serbia., 237-240.
Marković S, Stojković Simatović I, Ahmetović S, Veselinović L, Stojadinović S, Rac V, Škapin SD, Uskoković D. Enhanced photo(electro)catalytic properties of ZnO particles synthesized by CTAB-assisted microwave processing. Physical Chemistry 2018 : proceedings. Vol. 1 / 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry, September 24-28, 2018, Belgrade. 2018;:237-240.
Marković Smilja, Stojković Simatović Ivana, Ahmetović Sanita, Veselinović Ljiljana, Stojadinović Stevan, Rac Vladislav, Škapin Srečo Davor, Uskoković Dragan, "Enhanced photo(electro)catalytic properties of ZnO particles synthesized by CTAB-assisted microwave processing" Physical Chemistry 2018 : proceedings. Vol. 1 / 14th International Conference on Fundamental and Applied Aspects of Physical Chemistry, September 24-28, 2018, Belgrade (2018):237-240

Structural, morphological and optical characteristics of ZnO particles synthesized in the presence of surfactants CTAB and Pluronic F-127

Ahmetović, Sanita; Stojadinović, Stevan; Rac, Vladislav; Škapin, Srečo Davor; Stojković Simatović, Ivana; Marković, Smilja

(Belgrade : Institute of Technical Sciences of SASA, 2018)

TY  - CONF
AU  - Ahmetović, Sanita
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Škapin, Srečo Davor
AU  - Stojković Simatović, Ivana
AU  - Marković, Smilja
PY  - 2018
AB  - Due to its optical and electrical properties, low toxicity, chemical and physical stability, as well as inexpensiveness, zinc oxide (ZnO) based materials have a great potential to be used as photoelectrode in photo(electro)catalysis. Photo(electro)catalytic activity of ZnO materials can be improved by modification of particles morphology and surface topology. In this work, the influence of two different surfactants: cetyltrimethylammonium bromide (CTAB) and Pluronic F-127, on the crystal structure, morphology, optical and photo(electro)catalytic properties of ZnO particles, were examined. ZnO powders were synthesized by microwave processing of a precipitate which was previously prepared by "drop by drop" method in the presence of the surfactants. The crystal structure and phase purity of the ZnO particles were determined by X-ray diffraction and Raman spectroscopy. The effects of the surfactants on ZnO particles morphology were examined by the field emission scanning electron microscopy (FE-SEM). The optical properties were studied using UV-Vis diffuse reflectance and photoluminescence spectroscopy. Photocatalytic activity was examined via decolorization of methylene blue under direct sunlight irradiation. It was found that synthesized ZnO powders have a significant photocatalytic activity. Electrochemical properties were studied using linear sweep voltammetry and impedance spectroscopy in Na2SO4 electrolyte. ZnO powder synthesized in the presence of CTAB (ZnO/CTAB) showed the most significant reduction of potential and the fastest kinetic of oxygen evolution.
PB  - Belgrade : Institute of Technical Sciences of SASA
C3  - Program and the Book of Abstracts / Seventeenth Young Researchers' Conference Materials Sciences and Engineering, December 5-7, 2018, Belgrade, Serbia
T1  - Structural, morphological and optical characteristics of ZnO particles synthesized in the presence of surfactants CTAB and Pluronic F-127
SP  - 66
EP  - 66
UR  - https://hdl.handle.net/21.15107/rcub_dais_4724
ER  - 
@conference{
author = "Ahmetović, Sanita and Stojadinović, Stevan and Rac, Vladislav and Škapin, Srečo Davor and Stojković Simatović, Ivana and Marković, Smilja",
year = "2018",
abstract = "Due to its optical and electrical properties, low toxicity, chemical and physical stability, as well as inexpensiveness, zinc oxide (ZnO) based materials have a great potential to be used as photoelectrode in photo(electro)catalysis. Photo(electro)catalytic activity of ZnO materials can be improved by modification of particles morphology and surface topology. In this work, the influence of two different surfactants: cetyltrimethylammonium bromide (CTAB) and Pluronic F-127, on the crystal structure, morphology, optical and photo(electro)catalytic properties of ZnO particles, were examined. ZnO powders were synthesized by microwave processing of a precipitate which was previously prepared by "drop by drop" method in the presence of the surfactants. The crystal structure and phase purity of the ZnO particles were determined by X-ray diffraction and Raman spectroscopy. The effects of the surfactants on ZnO particles morphology were examined by the field emission scanning electron microscopy (FE-SEM). The optical properties were studied using UV-Vis diffuse reflectance and photoluminescence spectroscopy. Photocatalytic activity was examined via decolorization of methylene blue under direct sunlight irradiation. It was found that synthesized ZnO powders have a significant photocatalytic activity. Electrochemical properties were studied using linear sweep voltammetry and impedance spectroscopy in Na2SO4 electrolyte. ZnO powder synthesized in the presence of CTAB (ZnO/CTAB) showed the most significant reduction of potential and the fastest kinetic of oxygen evolution.",
publisher = "Belgrade : Institute of Technical Sciences of SASA",
journal = "Program and the Book of Abstracts / Seventeenth Young Researchers' Conference Materials Sciences and Engineering, December 5-7, 2018, Belgrade, Serbia",
title = "Structural, morphological and optical characteristics of ZnO particles synthesized in the presence of surfactants CTAB and Pluronic F-127",
pages = "66-66",
url = "https://hdl.handle.net/21.15107/rcub_dais_4724"
}
Ahmetović, S., Stojadinović, S., Rac, V., Škapin, S. D., Stojković Simatović, I.,& Marković, S. (2018). Structural, morphological and optical characteristics of ZnO particles synthesized in the presence of surfactants CTAB and Pluronic F-127.
Program and the Book of Abstracts / Seventeenth Young Researchers' Conference Materials Sciences and Engineering, December 5-7, 2018, Belgrade, Serbia
Belgrade : Institute of Technical Sciences of SASA., 66-66.
Ahmetović S, Stojadinović S, Rac V, Škapin SD, Stojković Simatović I, Marković S. Structural, morphological and optical characteristics of ZnO particles synthesized in the presence of surfactants CTAB and Pluronic F-127. Program and the Book of Abstracts / Seventeenth Young Researchers' Conference Materials Sciences and Engineering, December 5-7, 2018, Belgrade, Serbia. 2018;:66-66.
Ahmetović Sanita, Stojadinović Stevan, Rac Vladislav, Škapin Srečo Davor, Stojković Simatović Ivana, Marković Smilja, "Structural, morphological and optical characteristics of ZnO particles synthesized in the presence of surfactants CTAB and Pluronic F-127" Program and the Book of Abstracts / Seventeenth Young Researchers' Conference Materials Sciences and Engineering, December 5-7, 2018, Belgrade, Serbia (2018):66-66

Influence of point defects concentration on optical and photocatalytic properties of ZnO ceramics

Marković, Smilja; Rajić, Vladimir B.; Veselinović, Ljiljana; Belošević Čavor, Jelena; Škapin, Srečo Davor; Stojadinović, Stevan; Rac, Vladislav; Lević, Steva; Mojović, Miloš; Uskoković, Dragan

(Belgrade : Materials Research Society of Serbia, 2016)

TY  - CONF
AU  - Marković, Smilja
AU  - Rajić, Vladimir B.
AU  - Veselinović, Ljiljana
AU  - Belošević Čavor, Jelena
AU  - Škapin, Srečo Davor
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Lević, Steva
AU  - Mojović, Miloš
AU  - Uskoković, Dragan
PY  - 2016
AB  - Zinc oxide is one of the most studied materials due to its wide bandgap (3.37 eV) and large exciton binding energy (60 meV) which enables application in electronics, optoelectronics and spintronics. In the forms of single crystal and thin-film ZnO are used as UV and blue light emitter, while sintered ZnO-based ceramics are important as varistors, thermistors or semiconductors. It has been found that point defects in the crystal structure of a ZnO strongly influenced its electrical and optical properties. Neutral oxygen vacancies are considered to be a major component of the defect structure of ZnO. Thus, correlation of the oxygen vacancies concentration with band gap energy of ZnO product is important to its application in optoelectronic devices. In this study we investigated the influence of point defects concentration in ZnO crystal structure on its optical and photocatalytic properties. We analyzed ZnO powders prepared by different techniques: (a) microwave processing of precipitate and (b) hydrothermal processing, which yield different ordered crystal structure. To increase a concentration of the point defects in the crystal structure, the powders were sintered in air atmosphere by heating rate of 10 °/min up to 1100 °C, with dwell time of 1 h. The crystal structure, average crystallite size and phase purity of the ZnO ceramics were determined by X-ray diffraction and Raman spectroscopy. The optical properties, in particular, absorption capacity and bang gap energy, were studied using UV–Vis diffuse reflectance spectroscopy. To reveal the role of microstructures and point defects in ZnO crystal lattice, which are receptive for luminescence and photocatalytic activity of this functional oxide, photoluminescence (PL), photoluminescence excitation (PLE) and EPR spectra were analyzed. The influence of point defects concentration in the ZnO crystal structure on photocatalytic properties was examined via decolorization of methylene blue under direct sunlight irradiation. Correlation between amount of the point defects, absorption capacity and photocatalytic efficiency were established. In order to clarify the experimental results ab initio calculations based on density functional theory (DFT) were performed.
PB  - Belgrade : Materials Research Society of Serbia
C3  - Programme and The Book of Abstracts / Eighteenth Annual Conference YUCOMAT 2016, Herceg Novi, September 5-10, 2016
T1  - Influence of point defects concentration on optical and photocatalytic properties of ZnO ceramics
SP  - 34
EP  - 34
UR  - https://hdl.handle.net/21.15107/rcub_dais_902
ER  - 
@conference{
author = "Marković, Smilja and Rajić, Vladimir B. and Veselinović, Ljiljana and Belošević Čavor, Jelena and Škapin, Srečo Davor and Stojadinović, Stevan and Rac, Vladislav and Lević, Steva and Mojović, Miloš and Uskoković, Dragan",
year = "2016",
abstract = "Zinc oxide is one of the most studied materials due to its wide bandgap (3.37 eV) and large exciton binding energy (60 meV) which enables application in electronics, optoelectronics and spintronics. In the forms of single crystal and thin-film ZnO are used as UV and blue light emitter, while sintered ZnO-based ceramics are important as varistors, thermistors or semiconductors. It has been found that point defects in the crystal structure of a ZnO strongly influenced its electrical and optical properties. Neutral oxygen vacancies are considered to be a major component of the defect structure of ZnO. Thus, correlation of the oxygen vacancies concentration with band gap energy of ZnO product is important to its application in optoelectronic devices. In this study we investigated the influence of point defects concentration in ZnO crystal structure on its optical and photocatalytic properties. We analyzed ZnO powders prepared by different techniques: (a) microwave processing of precipitate and (b) hydrothermal processing, which yield different ordered crystal structure. To increase a concentration of the point defects in the crystal structure, the powders were sintered in air atmosphere by heating rate of 10 °/min up to 1100 °C, with dwell time of 1 h. The crystal structure, average crystallite size and phase purity of the ZnO ceramics were determined by X-ray diffraction and Raman spectroscopy. The optical properties, in particular, absorption capacity and bang gap energy, were studied using UV–Vis diffuse reflectance spectroscopy. To reveal the role of microstructures and point defects in ZnO crystal lattice, which are receptive for luminescence and photocatalytic activity of this functional oxide, photoluminescence (PL), photoluminescence excitation (PLE) and EPR spectra were analyzed. The influence of point defects concentration in the ZnO crystal structure on photocatalytic properties was examined via decolorization of methylene blue under direct sunlight irradiation. Correlation between amount of the point defects, absorption capacity and photocatalytic efficiency were established. In order to clarify the experimental results ab initio calculations based on density functional theory (DFT) were performed.",
publisher = "Belgrade : Materials Research Society of Serbia",
journal = "Programme and The Book of Abstracts / Eighteenth Annual Conference YUCOMAT 2016, Herceg Novi, September 5-10, 2016",
title = "Influence of point defects concentration on optical and photocatalytic properties of ZnO ceramics",
pages = "34-34",
url = "https://hdl.handle.net/21.15107/rcub_dais_902"
}
Marković, S., Rajić, V. B., Veselinović, L., Belošević Čavor, J., Škapin, S. D., Stojadinović, S., Rac, V., Lević, S., Mojović, M.,& Uskoković, D. (2016). Influence of point defects concentration on optical and photocatalytic properties of ZnO ceramics.
Programme and The Book of Abstracts / Eighteenth Annual Conference YUCOMAT 2016, Herceg Novi, September 5-10, 2016
Belgrade : Materials Research Society of Serbia., 34-34.
Marković S, Rajić VB, Veselinović L, Belošević Čavor J, Škapin SD, Stojadinović S, Rac V, Lević S, Mojović M, Uskoković D. Influence of point defects concentration on optical and photocatalytic properties of ZnO ceramics. Programme and The Book of Abstracts / Eighteenth Annual Conference YUCOMAT 2016, Herceg Novi, September 5-10, 2016. 2016;:34-34.
Marković Smilja, Rajić Vladimir B., Veselinović Ljiljana, Belošević Čavor Jelena, Škapin Srečo Davor, Stojadinović Stevan, Rac Vladislav, Lević Steva, Mojović Miloš, Uskoković Dragan, "Influence of point defects concentration on optical and photocatalytic properties of ZnO ceramics" Programme and The Book of Abstracts / Eighteenth Annual Conference YUCOMAT 2016, Herceg Novi, September 5-10, 2016 (2016):34-34

Influence of Point Defects Concentration on Densification Process and Optical Properties of Sintered ZnO Ceramics

Marković, Smilja; Stanković, Ana; Veselinović, Ljiljana; Belošević Čavor, Jelena; Škapin, Srečo Davor; Stojadinović, Stevan; Rac, Vladislav; Lević, Steva; Janković Častvan, Ivona; Uskoković, Dragan

(Belgrade : Materials Research Society of Serbia, 2015)

TY  - CONF
AU  - Marković, Smilja
AU  - Stanković, Ana
AU  - Veselinović, Ljiljana
AU  - Belošević Čavor, Jelena
AU  - Škapin, Srečo Davor
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Lević, Steva
AU  - Janković Častvan, Ivona
AU  - Uskoković, Dragan
PY  - 2015
AB  - Zinc oxide is one of the most studied materials due to its potential applications in electronics, optoelectronics and spintronics. In the forms of single crystal and thin-film ZnO could be used as UV and blue light emitter, while sintered ZnO-based ceramics are important as varistors, thermistors or wide-band gap semiconductors. Intrinsic defects, such as vacancies, interstitials and antisites, in the crystal structure of a ZnO strongly influenced its electrical and optical properties. Thus, understanding the behavior of intrinsic defects during densification of ZnO ceramics as well as correlation of the defects with band gap energy of final product is important to its application in opto-electronic devices.
In this study, the influence of point defects concentration on the densification process and optical properties of ZnO sintered ceramics was investigated. To obtain ZnO sintered ceramics with variety of point defects concentration we employed two starting powders with a different crystal structure ordering, as well different morphology and specific surface area. Sinterability of the powders was investigated by thermo mechanical analyzer; shrinkage data, collected in axial (h) direction during non-isothermal sintering with heating rates of 5, 10 and 20 °/min, were used to calculate activation energy of sintering process. Sintering of uniaxially pressed (P = 100 MPa) cylindrical compacts (ø 6 mm and h ≈ 3 mm) were done in air atmosphere by heating rate of 10 °/min up to 1100 and 1200 °C, and dwell time of 2 h. To study a crystal structure of the sintered samples XRD and Raman spectroscopy were used, for microstructural investigation field emission scanning electron micrographs were recorded while optical properties were determined by UV-Vis diffuse reflectance and photoluminescence spectroscopy. A detailed study shows that point defect strongly influenced densification process as well optical properties. Sintered ZnO ceramic with a high crystal defect concentration and nanosized grains shows band gap energy of about 2 eV while band gap energy increased with a decrease of defect concentration.
PB  - Belgrade : Materials Research Society of Serbia
C3  - Programme and The Book of Abstracts / Seventeenth Annual Conference YUCOMAT 205, Herceg Novi, August 31– September 4, 2015
T1  - Influence of Point Defects Concentration on Densification Process and Optical Properties of Sintered ZnO Ceramics
SP  - 61
EP  - 61
UR  - https://hdl.handle.net/21.15107/rcub_dais_831
ER  - 
@conference{
author = "Marković, Smilja and Stanković, Ana and Veselinović, Ljiljana and Belošević Čavor, Jelena and Škapin, Srečo Davor and Stojadinović, Stevan and Rac, Vladislav and Lević, Steva and Janković Častvan, Ivona and Uskoković, Dragan",
year = "2015",
abstract = "Zinc oxide is one of the most studied materials due to its potential applications in electronics, optoelectronics and spintronics. In the forms of single crystal and thin-film ZnO could be used as UV and blue light emitter, while sintered ZnO-based ceramics are important as varistors, thermistors or wide-band gap semiconductors. Intrinsic defects, such as vacancies, interstitials and antisites, in the crystal structure of a ZnO strongly influenced its electrical and optical properties. Thus, understanding the behavior of intrinsic defects during densification of ZnO ceramics as well as correlation of the defects with band gap energy of final product is important to its application in opto-electronic devices.
In this study, the influence of point defects concentration on the densification process and optical properties of ZnO sintered ceramics was investigated. To obtain ZnO sintered ceramics with variety of point defects concentration we employed two starting powders with a different crystal structure ordering, as well different morphology and specific surface area. Sinterability of the powders was investigated by thermo mechanical analyzer; shrinkage data, collected in axial (h) direction during non-isothermal sintering with heating rates of 5, 10 and 20 °/min, were used to calculate activation energy of sintering process. Sintering of uniaxially pressed (P = 100 MPa) cylindrical compacts (ø 6 mm and h ≈ 3 mm) were done in air atmosphere by heating rate of 10 °/min up to 1100 and 1200 °C, and dwell time of 2 h. To study a crystal structure of the sintered samples XRD and Raman spectroscopy were used, for microstructural investigation field emission scanning electron micrographs were recorded while optical properties were determined by UV-Vis diffuse reflectance and photoluminescence spectroscopy. A detailed study shows that point defect strongly influenced densification process as well optical properties. Sintered ZnO ceramic with a high crystal defect concentration and nanosized grains shows band gap energy of about 2 eV while band gap energy increased with a decrease of defect concentration.",
publisher = "Belgrade : Materials Research Society of Serbia",
journal = "Programme and The Book of Abstracts / Seventeenth Annual Conference YUCOMAT 205, Herceg Novi, August 31– September 4, 2015",
title = "Influence of Point Defects Concentration on Densification Process and Optical Properties of Sintered ZnO Ceramics",
pages = "61-61",
url = "https://hdl.handle.net/21.15107/rcub_dais_831"
}
Marković, S., Stanković, A., Veselinović, L., Belošević Čavor, J., Škapin, S. D., Stojadinović, S., Rac, V., Lević, S., Janković Častvan, I.,& Uskoković, D. (2015). Influence of Point Defects Concentration on Densification Process and Optical Properties of Sintered ZnO Ceramics.
Programme and The Book of Abstracts / Seventeenth Annual Conference YUCOMAT 205, Herceg Novi, August 31– September 4, 2015
Belgrade : Materials Research Society of Serbia., 61-61.
Marković S, Stanković A, Veselinović L, Belošević Čavor J, Škapin SD, Stojadinović S, Rac V, Lević S, Janković Častvan I, Uskoković D. Influence of Point Defects Concentration on Densification Process and Optical Properties of Sintered ZnO Ceramics. Programme and The Book of Abstracts / Seventeenth Annual Conference YUCOMAT 205, Herceg Novi, August 31– September 4, 2015. 2015;:61-61.
Marković Smilja, Stanković Ana, Veselinović Ljiljana, Belošević Čavor Jelena, Škapin Srečo Davor, Stojadinović Stevan, Rac Vladislav, Lević Steva, Janković Častvan Ivona, Uskoković Dragan, "Influence of Point Defects Concentration on Densification Process and Optical Properties of Sintered ZnO Ceramics" Programme and The Book of Abstracts / Seventeenth Annual Conference YUCOMAT 205, Herceg Novi, August 31– September 4, 2015 (2015):61-61