TY  - JOUR
AU  - Aleksić, Katarina
AU  - Stojković Simatović, Ivana
AU  - Stanković, Ana
AU  - Veselinović, Ljiljana
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Radmilović, Nadežda
AU  - Rajić, Vladimir
AU  - Škapin, Srečo Davor
AU  - Mančić, Lidija
AU  - Marković, Smilja
PY  - 2023
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/6368
AB  - Catalytic materials are the greatest challenge for the commercial application of water electrolysis (WEs) and fuel cells (FCs) as clean energy technologies. There is a need to find an alternative to expensive and unavailable platinum group metal (PGM) catalysts. This study aimed to reduce the cost of PGM materials by replacing Ru with RuO2 and lowering the amount of RuO2 by adding abundant and multifunctional ZnO. A ZnO@RuO2 composite in a 10:1 molar ratio was synthesized by microwave processing of a precipitate as a green, low-cost, and fast method, and then annealed at 300°C and 600°C to improve the catalytic properties. The physicochemical properties of the ZnO@RuO2 composites were investigated by X-ray powder diffraction (XRD), Raman and Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), UV-Vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The electrochemical activity of the samples was investigated by linear sweep voltammetry in acidic and alkaline electrolytes. We observed good bifunctional catalytic activity of the ZnO@RuO2 composites toward HER and OER in both electrolytes. The improved bifunctional catalytic activity of the ZnO@RuO2 composite by annealing was discussed and attributed to the reduced number of bulk oxygen vacancies and the increased number of established heterojunctions. Copyright © 2023 Aleksić, Stojković Simatović, Stanković, Veselinović, Stojadinović, Rac, Radmilović, Rajić, Škapin, Mančić and Marković.
T2  - Frontiers in Chemistry
T2  - Frontiers in Chemistry
T1  - Enhancement of ZnO@RuO2 bifunctional photo-electro catalytic activity toward water splitting
VL  - 11
DO  - 10.3389/fchem.2023.1173910
ER  - 

@article{
author = "Aleksić, Katarina and Stojković Simatović, Ivana and Stanković, Ana and Veselinović, Ljiljana and Stojadinović, Stevan and Rac, Vladislav and Radmilović, Nadežda and Rajić, Vladimir and Škapin, Srečo Davor and Mančić, Lidija and Marković, Smilja",
year = "2023",
abstract = "Catalytic materials are the greatest challenge for the commercial application of water electrolysis (WEs) and fuel cells (FCs) as clean energy technologies. There is a need to find an alternative to expensive and unavailable platinum group metal (PGM) catalysts. This study aimed to reduce the cost of PGM materials by replacing Ru with RuO2 and lowering the amount of RuO2 by adding abundant and multifunctional ZnO. A ZnO@RuO2 composite in a 10:1 molar ratio was synthesized by microwave processing of a precipitate as a green, low-cost, and fast method, and then annealed at 300°C and 600°C to improve the catalytic properties. The physicochemical properties of the ZnO@RuO2 composites were investigated by X-ray powder diffraction (XRD), Raman and Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), UV-Vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The electrochemical activity of the samples was investigated by linear sweep voltammetry in acidic and alkaline electrolytes. We observed good bifunctional catalytic activity of the ZnO@RuO2 composites toward HER and OER in both electrolytes. The improved bifunctional catalytic activity of the ZnO@RuO2 composite by annealing was discussed and attributed to the reduced number of bulk oxygen vacancies and the increased number of established heterojunctions. Copyright © 2023 Aleksić, Stojković Simatović, Stanković, Veselinović, Stojadinović, Rac, Radmilović, Rajić, Škapin, Mančić and Marković.",
journal = "Frontiers in Chemistry, Frontiers in Chemistry",
title = "Enhancement of ZnO@RuO2 bifunctional photo-electro catalytic activity toward water splitting",
volume = "11",
doi = "10.3389/fchem.2023.1173910"
}

Aleksić, K., Stojković Simatović, I., Stanković, A., Veselinović, L., Stojadinović, S., Rac, V., Radmilović, N., Rajić, V., Škapin, S. D., Mančić, L.,& Marković, S.. (2023). Enhancement of ZnO@RuO2 bifunctional photo-electro catalytic activity toward water splitting. in Frontiers in Chemistry, 11.
https://doi.org/10.3389/fchem.2023.1173910

Aleksić K, Stojković Simatović I, Stanković A, Veselinović L, Stojadinović S, Rac V, Radmilović N, Rajić V, Škapin SD, Mančić L, Marković S. Enhancement of ZnO@RuO2 bifunctional photo-electro catalytic activity toward water splitting. in Frontiers in Chemistry. 2023;11.
doi:10.3389/fchem.2023.1173910 .

Aleksić, Katarina, Stojković Simatović, Ivana, Stanković, Ana, Veselinović, Ljiljana, Stojadinović, Stevan, Rac, Vladislav, Radmilović, Nadežda, Rajić, Vladimir, Škapin, Srečo Davor, Mančić, Lidija, Marković, Smilja, "Enhancement of ZnO@RuO2 bifunctional photo-electro catalytic activity toward water splitting" in Frontiers in Chemistry, 11 (2023),
https://doi.org/10.3389/fchem.2023.1173910 . .

TY  - JOUR
AU  - Rajić, Vladimir
AU  - Stojković-Simatović, Ivana
AU  - Veselinović, Ljiljana
AU  - Belosević-Cavor, Jelena
AU  - Novaković, Mirjana
AU  - Popović, Maja
AU  - Skapin, Sreco Davor
AU  - Mojović, Milos
AU  - Stojadinović, Stevan
AU  - Rac, Vladislav
AU  - Janković-Castvan, Ivona
AU  - Marković, Smilja
PY  - 2020
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/5324
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 Zn(2+)partial substitution with Fe(3+)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 Vvs.RHE), current density (0.231 mA cm(-2)at 0.150 Vvs.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 (0001x304;) facets. Quite the contrary, the OER study showed that the introduction of Fe(3+)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 Vvs.RHE, an onset potential of 1.856 Vvs.RHE, and the smallest potential difference between the OER and ORR (Delta E= 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 Soc Chemistry, Cambridge
T2  - Physical Chemistry Chemical Physics
T1  - Bifunctional catalytic activity of Zn1-xFexO toward the OER/ORR: seeking an optimal stoichiometry
EP  - 22095
IS  - 38
SP  - 22078
VL  - 22
DO  - 10.1039/d0cp03377d
ER  - 

@article{
author = "Rajić, Vladimir and Stojković-Simatović, Ivana and Veselinović, Ljiljana and Belosević-Cavor, Jelena and Novaković, Mirjana and Popović, Maja and Skapin, Sreco Davor and Mojović, Milos and Stojadinović, Stevan and Rac, Vladislav and Janković-Castvan, 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 Zn(2+)partial substitution with Fe(3+)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 Vvs.RHE), current density (0.231 mA cm(-2)at 0.150 Vvs.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 (0001x304;) facets. Quite the contrary, the OER study showed that the introduction of Fe(3+)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 Vvs.RHE, an onset potential of 1.856 Vvs.RHE, and the smallest potential difference between the OER and ORR (Delta E= 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 Soc Chemistry, Cambridge",
journal = "Physical Chemistry Chemical Physics",
title = "Bifunctional catalytic activity of Zn1-xFexO toward the OER/ORR: seeking an optimal stoichiometry",
pages = "22095-22078",
number = "38",
volume = "22",
doi = "10.1039/d0cp03377d"
}

Rajić, V., Stojković-Simatović, I., Veselinović, L., Belosević-Cavor, J., Novaković, M., Popović, M., Skapin, S. D., Mojović, M., Stojadinović, S., Rac, V., Janković-Castvan, I.,& Marković, S.. (2020). Bifunctional catalytic activity of Zn1-xFexO toward the OER/ORR: seeking an optimal stoichiometry. in Physical Chemistry Chemical Physics
Royal Soc Chemistry, Cambridge., 22(38), 22078-22095.
https://doi.org/10.1039/d0cp03377d

Rajić V, Stojković-Simatović I, Veselinović L, Belosević-Cavor J, Novaković M, Popović M, Skapin SD, Mojović M, Stojadinović S, Rac V, Janković-Castvan I, Marković S. Bifunctional catalytic activity of Zn1-xFexO toward the OER/ORR: seeking an optimal stoichiometry. in Physical Chemistry Chemical Physics. 2020;22(38):22078-22095.
doi:10.1039/d0cp03377d .

Rajić, Vladimir, Stojković-Simatović, Ivana, Veselinović, Ljiljana, Belosević-Cavor, Jelena, Novaković, Mirjana, Popović, Maja, Skapin, Sreco Davor, Mojović, Milos, Stojadinović, Stevan, Rac, Vladislav, Janković-Castvan, Ivona, Marković, Smilja, "Bifunctional catalytic activity of Zn1-xFexO toward the OER/ORR: seeking an optimal stoichiometry" in Physical Chemistry Chemical Physics, 22, no. 38 (2020):22078-22095,
https://doi.org/10.1039/d0cp03377d . .