Kovač, Janez

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orcid::0000-0002-4324-246X
  • Kovač, Janez (10)
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Author's Bibliography

Palladium-copper bimetallic surfaces as electrocatalysts for the ethanol oxidation in an alkaline medium

Obradović, Maja; Lačnjevac, Uroš; Radmilovic, Vuk; Gavrilović-Wohlmuther, Aleksandra; Kovač, Janez; Rogan, Jelena R.; Radmilović, Velimir R.; Gojković, Snežana Lj.

(Elsevier B.V., 2023)

TY  - JOUR
AU  - Obradović, Maja
AU  - Lačnjevac, Uroš
AU  - Radmilovic, Vuk
AU  - Gavrilović-Wohlmuther, Aleksandra
AU  - Kovač, Janez
AU  - Rogan, Jelena R.
AU  - Radmilović, Velimir R.
AU  - Gojković, Snežana Lj.
PY  - 2023
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2782
AB  - Two types of Cu-modified Pd catalysts supported on high area carbon were prepared: Pd nanoparticles modified
with a sub-monolayer of underpotentially deposited Cu (Cu@Pd/C) and Pd-Cu alloy nanoparticles (Pd-Cu/C),
and examined for the ethanol oxidation reaction (EOR) in alkaline solution. The catalysts were characterized by
energy-dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy and X-ray photoelectron
spectroscopy, as well as cyclic voltammetry. As reference catalysts, Pd/C and Pt/C were used. The electrochemically
active surface area of all samples was determined from COads and Cuupd desorption and Pd oxide
reduction, and used to assess their intrinsic activity for EOR. Intimate contact of Pd with Cu atoms enhanced its
activity, regardless of the type of bimetal catalyst. The atomic Pd:Cu ratio between 2:1 and 4:1 appears to be
optimal for high activity. The most active catalyst under the potentiodynamic conditions was Cu@Pd/C with
θ(Cu) = 0.21,although Pd-Cu/C was superior during the potentiostatic test. All bimetallic catalysts surpassed
Pd/C in mass activity. The EOR activity of Pt/C was higher compared to Pd-based catalysts at low potentials,
both in terms of specific and mass activity, but with a significant decline over a 30-min potentiostatic stability
test.
PB  - Elsevier B.V.
T2  - Journal of Electroanalytical Chemistry
T1  - Palladium-copper bimetallic surfaces as electrocatalysts for the ethanol oxidation in an alkaline medium
SP  - 117673
VL  - 944
DO  - 10.1016/j.jelechem.2023.117673
ER  - 
@article{
author = "Obradović, Maja and Lačnjevac, Uroš and Radmilovic, Vuk and Gavrilović-Wohlmuther, Aleksandra and Kovač, Janez and Rogan, Jelena R. and Radmilović, Velimir R. and Gojković, Snežana Lj.",
year = "2023",
abstract = "Two types of Cu-modified Pd catalysts supported on high area carbon were prepared: Pd nanoparticles modified
with a sub-monolayer of underpotentially deposited Cu (Cu@Pd/C) and Pd-Cu alloy nanoparticles (Pd-Cu/C),
and examined for the ethanol oxidation reaction (EOR) in alkaline solution. The catalysts were characterized by
energy-dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy and X-ray photoelectron
spectroscopy, as well as cyclic voltammetry. As reference catalysts, Pd/C and Pt/C were used. The electrochemically
active surface area of all samples was determined from COads and Cuupd desorption and Pd oxide
reduction, and used to assess their intrinsic activity for EOR. Intimate contact of Pd with Cu atoms enhanced its
activity, regardless of the type of bimetal catalyst. The atomic Pd:Cu ratio between 2:1 and 4:1 appears to be
optimal for high activity. The most active catalyst under the potentiodynamic conditions was Cu@Pd/C with
θ(Cu) = 0.21,although Pd-Cu/C was superior during the potentiostatic test. All bimetallic catalysts surpassed
Pd/C in mass activity. The EOR activity of Pt/C was higher compared to Pd-based catalysts at low potentials,
both in terms of specific and mass activity, but with a significant decline over a 30-min potentiostatic stability
test.",
publisher = "Elsevier B.V.",
journal = "Journal of Electroanalytical Chemistry",
title = "Palladium-copper bimetallic surfaces as electrocatalysts for the ethanol oxidation in an alkaline medium",
pages = "117673",
volume = "944",
doi = "10.1016/j.jelechem.2023.117673"
}
Obradović, M., Lačnjevac, U., Radmilovic, V., Gavrilović-Wohlmuther, A., Kovač, J., Rogan, J. R., Radmilović, V. R.,& Gojković, S. Lj.. (2023). Palladium-copper bimetallic surfaces as electrocatalysts for the ethanol oxidation in an alkaline medium. in Journal of Electroanalytical Chemistry
Elsevier B.V.., 944, 117673.
https://doi.org/10.1016/j.jelechem.2023.117673
Obradović M, Lačnjevac U, Radmilovic V, Gavrilović-Wohlmuther A, Kovač J, Rogan JR, Radmilović VR, Gojković SL. Palladium-copper bimetallic surfaces as electrocatalysts for the ethanol oxidation in an alkaline medium. in Journal of Electroanalytical Chemistry. 2023;944:117673.
doi:10.1016/j.jelechem.2023.117673 .
Obradović, Maja, Lačnjevac, Uroš, Radmilovic, Vuk, Gavrilović-Wohlmuther, Aleksandra, Kovač, Janez, Rogan, Jelena R., Radmilović, Velimir R., Gojković, Snežana Lj., "Palladium-copper bimetallic surfaces as electrocatalysts for the ethanol oxidation in an alkaline medium" in Journal of Electroanalytical Chemistry, 944 (2023):117673,
https://doi.org/10.1016/j.jelechem.2023.117673 . .
2

Synthesis, structure and electrochemical performance of NiMn2O4

Dojčinović, Milena; Vasiljević, Zorka Z; Tadić, Nenad B.; Krstić, Jugoslav B.; Marković, Smilja; Spreitzer, Matjaž; Kovač, Janez; Nikolić, Maria Vesna

(Novi Sad : Faculty of Technology, 2021)

TY  - CONF
AU  - Dojčinović, Milena
AU  - Vasiljević, Zorka Z
AU  - Tadić, Nenad B.
AU  - Krstić, Jugoslav B.
AU  - Marković, Smilja
AU  - Spreitzer, Matjaž
AU  - Kovač, Janez
AU  - Nikolić, Maria Vesna
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/12397
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1630
AB  - NiMn2O4, with a cubic spinel structure and numerous and various applications in modern technology, were synthesized with two synthetic routes: sol-gel combustion method with glycine as fuel and electrospinning method with polyvinylpyrrolidone (PVP). Both amorphous powders from sol-gel synthesis and as-spun fibers from electrospinning synthesis were calcined, electrospun fibers at 400 °C and the sol-gel synthesized powders at 800 °C. Electrospun fibers were previously characterized with DTA-TGA to investigate the influence of thermal process on a polymer fiber.The obtained powders were characterized accordingly. Structural analysis was done via X-ray diffraction (XRD) and results show spinel structure with no impurity. The texture and morphology was investigated via N2 physisorption and transmission electron microscopy (TEM), respectively. Chemical states of elements were investigated by X-ray photoelectron spectroscopy (XPS). The electrochemical performance of the synthesized materials as supercapacitors was tested via cyclic voltammetry (CV), electric impedance spectroscopy (EIS), and chronopotentiometry (CP) to aquire galvanostatic charge-discharge (GCD) curves. Experiments were done in 6 M KOH solution with nickel foam as a working electrode. The results show good electrochemical capacity circa 200 F/g, with the potential for further structural improvement of the materials.
PB  - Novi Sad : Faculty of Technology
C3  - Programme and book of abstracts / 14th ECerS Conference for Young Scientists in Ceramics (CYSC-2021), October 20-23, 2021, Novi Sad
T1  - Synthesis, structure and electrochemical performance of NiMn2O4
EP  - 81
SP  - 81
UR  - https://hdl.handle.net/21.15107/rcub_dais_12397
ER  - 
@conference{
author = "Dojčinović, Milena and Vasiljević, Zorka Z and Tadić, Nenad B. and Krstić, Jugoslav B. and Marković, Smilja and Spreitzer, Matjaž and Kovač, Janez and Nikolić, Maria Vesna",
year = "2021",
abstract = "NiMn2O4, with a cubic spinel structure and numerous and various applications in modern technology, were synthesized with two synthetic routes: sol-gel combustion method with glycine as fuel and electrospinning method with polyvinylpyrrolidone (PVP). Both amorphous powders from sol-gel synthesis and as-spun fibers from electrospinning synthesis were calcined, electrospun fibers at 400 °C and the sol-gel synthesized powders at 800 °C. Electrospun fibers were previously characterized with DTA-TGA to investigate the influence of thermal process on a polymer fiber.The obtained powders were characterized accordingly. Structural analysis was done via X-ray diffraction (XRD) and results show spinel structure with no impurity. The texture and morphology was investigated via N2 physisorption and transmission electron microscopy (TEM), respectively. Chemical states of elements were investigated by X-ray photoelectron spectroscopy (XPS). The electrochemical performance of the synthesized materials as supercapacitors was tested via cyclic voltammetry (CV), electric impedance spectroscopy (EIS), and chronopotentiometry (CP) to aquire galvanostatic charge-discharge (GCD) curves. Experiments were done in 6 M KOH solution with nickel foam as a working electrode. The results show good electrochemical capacity circa 200 F/g, with the potential for further structural improvement of the materials.",
publisher = "Novi Sad : Faculty of Technology",
journal = "Programme and book of abstracts / 14th ECerS Conference for Young Scientists in Ceramics (CYSC-2021), October 20-23, 2021, Novi Sad",
title = "Synthesis, structure and electrochemical performance of NiMn2O4",
pages = "81-81",
url = "https://hdl.handle.net/21.15107/rcub_dais_12397"
}
Dojčinović, M., Vasiljević, Z. Z., Tadić, N. B., Krstić, J. B., Marković, S., Spreitzer, M., Kovač, J.,& Nikolić, M. V.. (2021). Synthesis, structure and electrochemical performance of NiMn2O4. in Programme and book of abstracts / 14th ECerS Conference for Young Scientists in Ceramics (CYSC-2021), October 20-23, 2021, Novi Sad
Novi Sad : Faculty of Technology., 81-81.
https://hdl.handle.net/21.15107/rcub_dais_12397
Dojčinović M, Vasiljević ZZ, Tadić NB, Krstić JB, Marković S, Spreitzer M, Kovač J, Nikolić MV. Synthesis, structure and electrochemical performance of NiMn2O4. in Programme and book of abstracts / 14th ECerS Conference for Young Scientists in Ceramics (CYSC-2021), October 20-23, 2021, Novi Sad. 2021;:81-81.
https://hdl.handle.net/21.15107/rcub_dais_12397 .
Dojčinović, Milena, Vasiljević, Zorka Z, Tadić, Nenad B., Krstić, Jugoslav B., Marković, Smilja, Spreitzer, Matjaž, Kovač, Janez, Nikolić, Maria Vesna, "Synthesis, structure and electrochemical performance of NiMn2O4" in Programme and book of abstracts / 14th ECerS Conference for Young Scientists in Ceramics (CYSC-2021), October 20-23, 2021, Novi Sad (2021):81-81,
https://hdl.handle.net/21.15107/rcub_dais_12397 .

Exploring the impact of calcination parameters on the crystal structure, morphology, and optical properties of electrospun Fe2TiO5 nanofibers

Vasiljević, Zorka Z; Dojčinović, Milena; Vujančević, Jelena; Spreitzer, Matjaz; Kovač, Janez; Bartolić, Dragana; Marković, Smilja; Jankovic-Castvan, Ivona; Tadić, Nenad B.; Nikolić, Maria Vesna

(Royal Soc Chemistry, Cambridge, 2021)

TY  - JOUR
AU  - Vasiljević, Zorka Z
AU  - Dojčinović, Milena
AU  - Vujančević, Jelena
AU  - Spreitzer, Matjaz
AU  - Kovač, Janez
AU  - Bartolić, Dragana
AU  - Marković, Smilja
AU  - Jankovic-Castvan, Ivona
AU  - Tadić, Nenad B.
AU  - Nikolić, Maria Vesna
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1403
AB  - Nanostructured Fe2TiO5 (pseudobrookite), a mixed metal oxide material holds significant promise for utilization in energy and environmental applications. However, its full application is still hindered due to the difficulty to synthesize monophasic Fe2TiO5 with high crystallinity and a large specific surface area. Herein, Fe2TiO5 nanofibers were synthesized via a versatile and low-cost electrospinning method, followed by a calcination process at different temperatures. We found a significant effect of the calcination process and its duration on the crystalline phase in the form of either pseudobrookite or pseudobrookite-hematite-rutile and the morphology of calcined nanofibers. The crystallite size increased whereas the specific surface area decreased with an increase in calcination temperature. At higher temperatures, the growth of Fe2TiO5 nanoparticles and simultaneous coalescence of small particles was noted. The highest specific surface area was obtained for the sample calcined at 500 degrees C for 6 h (S-BET = 64.4 m(2) g(-1)). This work opens new opportunities in the synthesis of Fe2TiO5 nanostructures using the electrospinning method and a subsequent optimized calcination process for energy-related applications.
PB  - Royal Soc Chemistry, Cambridge
T2  - RSC Advances
T1  - Exploring the impact of calcination parameters on the crystal structure, morphology, and optical properties of electrospun Fe2TiO5 nanofibers
EP  - 32368
IS  - 51
SP  - 32358
VL  - 11
DO  - 10.1039/d1ra05748k
ER  - 
@article{
author = "Vasiljević, Zorka Z and Dojčinović, Milena and Vujančević, Jelena and Spreitzer, Matjaz and Kovač, Janez and Bartolić, Dragana and Marković, Smilja and Jankovic-Castvan, Ivona and Tadić, Nenad B. and Nikolić, Maria Vesna",
year = "2021",
abstract = "Nanostructured Fe2TiO5 (pseudobrookite), a mixed metal oxide material holds significant promise for utilization in energy and environmental applications. However, its full application is still hindered due to the difficulty to synthesize monophasic Fe2TiO5 with high crystallinity and a large specific surface area. Herein, Fe2TiO5 nanofibers were synthesized via a versatile and low-cost electrospinning method, followed by a calcination process at different temperatures. We found a significant effect of the calcination process and its duration on the crystalline phase in the form of either pseudobrookite or pseudobrookite-hematite-rutile and the morphology of calcined nanofibers. The crystallite size increased whereas the specific surface area decreased with an increase in calcination temperature. At higher temperatures, the growth of Fe2TiO5 nanoparticles and simultaneous coalescence of small particles was noted. The highest specific surface area was obtained for the sample calcined at 500 degrees C for 6 h (S-BET = 64.4 m(2) g(-1)). This work opens new opportunities in the synthesis of Fe2TiO5 nanostructures using the electrospinning method and a subsequent optimized calcination process for energy-related applications.",
publisher = "Royal Soc Chemistry, Cambridge",
journal = "RSC Advances",
title = "Exploring the impact of calcination parameters on the crystal structure, morphology, and optical properties of electrospun Fe2TiO5 nanofibers",
pages = "32368-32358",
number = "51",
volume = "11",
doi = "10.1039/d1ra05748k"
}
Vasiljević, Z. Z., Dojčinović, M., Vujančević, J., Spreitzer, M., Kovač, J., Bartolić, D., Marković, S., Jankovic-Castvan, I., Tadić, N. B.,& Nikolić, M. V.. (2021). Exploring the impact of calcination parameters on the crystal structure, morphology, and optical properties of electrospun Fe2TiO5 nanofibers. in RSC Advances
Royal Soc Chemistry, Cambridge., 11(51), 32358-32368.
https://doi.org/10.1039/d1ra05748k
Vasiljević ZZ, Dojčinović M, Vujančević J, Spreitzer M, Kovač J, Bartolić D, Marković S, Jankovic-Castvan I, Tadić NB, Nikolić MV. Exploring the impact of calcination parameters on the crystal structure, morphology, and optical properties of electrospun Fe2TiO5 nanofibers. in RSC Advances. 2021;11(51):32358-32368.
doi:10.1039/d1ra05748k .
Vasiljević, Zorka Z, Dojčinović, Milena, Vujančević, Jelena, Spreitzer, Matjaz, Kovač, Janez, Bartolić, Dragana, Marković, Smilja, Jankovic-Castvan, Ivona, Tadić, Nenad B., Nikolić, Maria Vesna, "Exploring the impact of calcination parameters on the crystal structure, morphology, and optical properties of electrospun Fe2TiO5 nanofibers" in RSC Advances, 11, no. 51 (2021):32358-32368,
https://doi.org/10.1039/d1ra05748k . .
12
12

Nickel Manganite-Sodium Alginate Nano-Biocomposite for Temperature Sensing

Dojčinović, Milena; Vasiljević, Zorka Z; Kovač, Janez; Tadić, Nenad B.; Nikolić, Maria Vesna

(MDPI, Basel, 2021)

TY  - JOUR
AU  - Dojčinović, Milena
AU  - Vasiljević, Zorka Z
AU  - Kovač, Janez
AU  - Tadić, Nenad B.
AU  - Nikolić, Maria Vesna
PY  - 2021
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1400
AB  - Nanocrystalline nickel manganite (NiMn2O4) powder with a pure cubic spinel phase structure was synthesized via sol-gel combustion and characterized with XRD, FT-IR, XPS and SEM. The powder was mixed with sodium alginate gel to form a nano-biocomposite gel, dried at room temperature to form a thick film and characterized with FT-IR and SEM. DC resistance and AC impedance of sensor test structures obtained by drop casting the nano-biocomposite gel onto test interdigitated PdAg electrodes on an alumina substrate were measured in the temperature range of 20-50 degrees C at a constant relative humidity (RH) of 50% and at room temperature (25 degrees C) in the RH range of 40-90%. The material constant obtained from the measured decrease in resistance with temperature was determined to be 4523 K, while the temperature sensitivity at room temperature (25 degrees C) was -5.09%/K. Analysis of the complex impedance plots showed a dominant influence of grains. The decrease in complex impedance with increase in temperature confirmed the negative temperature coefficient effect. The grain resistance and grain relaxation frequency were determined using an equivalent circuit. The activation energy for conduction was determined as 0.45 eV from the temperature dependence of the grain resistance according to the small polaron hopping model, while the activation energy for relaxation was 0.43 eV determined from the Arrhenius dependence of the grain relaxation frequency on temperature.
PB  - MDPI, Basel
T2  - Chemosensors
T1  - Nickel Manganite-Sodium Alginate Nano-Biocomposite for Temperature Sensing
IS  - 9
VL  - 9
DO  - 10.3390/chemosensors9090241
ER  - 
@article{
author = "Dojčinović, Milena and Vasiljević, Zorka Z and Kovač, Janez and Tadić, Nenad B. and Nikolić, Maria Vesna",
year = "2021",
abstract = "Nanocrystalline nickel manganite (NiMn2O4) powder with a pure cubic spinel phase structure was synthesized via sol-gel combustion and characterized with XRD, FT-IR, XPS and SEM. The powder was mixed with sodium alginate gel to form a nano-biocomposite gel, dried at room temperature to form a thick film and characterized with FT-IR and SEM. DC resistance and AC impedance of sensor test structures obtained by drop casting the nano-biocomposite gel onto test interdigitated PdAg electrodes on an alumina substrate were measured in the temperature range of 20-50 degrees C at a constant relative humidity (RH) of 50% and at room temperature (25 degrees C) in the RH range of 40-90%. The material constant obtained from the measured decrease in resistance with temperature was determined to be 4523 K, while the temperature sensitivity at room temperature (25 degrees C) was -5.09%/K. Analysis of the complex impedance plots showed a dominant influence of grains. The decrease in complex impedance with increase in temperature confirmed the negative temperature coefficient effect. The grain resistance and grain relaxation frequency were determined using an equivalent circuit. The activation energy for conduction was determined as 0.45 eV from the temperature dependence of the grain resistance according to the small polaron hopping model, while the activation energy for relaxation was 0.43 eV determined from the Arrhenius dependence of the grain relaxation frequency on temperature.",
publisher = "MDPI, Basel",
journal = "Chemosensors",
title = "Nickel Manganite-Sodium Alginate Nano-Biocomposite for Temperature Sensing",
number = "9",
volume = "9",
doi = "10.3390/chemosensors9090241"
}
Dojčinović, M., Vasiljević, Z. Z., Kovač, J., Tadić, N. B.,& Nikolić, M. V.. (2021). Nickel Manganite-Sodium Alginate Nano-Biocomposite for Temperature Sensing. in Chemosensors
MDPI, Basel., 9(9).
https://doi.org/10.3390/chemosensors9090241
Dojčinović M, Vasiljević ZZ, Kovač J, Tadić NB, Nikolić MV. Nickel Manganite-Sodium Alginate Nano-Biocomposite for Temperature Sensing. in Chemosensors. 2021;9(9).
doi:10.3390/chemosensors9090241 .
Dojčinović, Milena, Vasiljević, Zorka Z, Kovač, Janez, Tadić, Nenad B., Nikolić, Maria Vesna, "Nickel Manganite-Sodium Alginate Nano-Biocomposite for Temperature Sensing" in Chemosensors, 9, no. 9 (2021),
https://doi.org/10.3390/chemosensors9090241 . .
7
7

Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route

Albrbar, Asma Juma; Djokic, Veljko; Bjelajac, Anđelika; Kovač, Janez; Ćirković, Jovana; Mitrić, Miodrag; Janacković, Đorđe; Petrović, Rada

(Elsevier Sci Ltd, Oxford, 2016)

TY  - JOUR
AU  - Albrbar, Asma Juma
AU  - Djokic, Veljko
AU  - Bjelajac, Anđelika
AU  - Kovač, Janez
AU  - Ćirković, Jovana
AU  - Mitrić, Miodrag
AU  - Janacković, Đorđe
AU  - Petrović, Rada
PY  - 2016
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/984
AB  - Visible-light active mesoporous N,S-doped and co-doped anatase TiO2 powders were synthesized by non-hydrolytic sol-gel route, starting from TiCl4 and Ti((OPr)-Pr-i)(4) dissolved in cyclohexane or dimethyl sulfoxide, later used as a S-doping agent. After drying in an inert atmosphere, the gels were annealed at 500 degrees C for 3 h, in air or ammonia flow, later used for N-doping. The undoped titania powder, obtained by annealing in air of the cyclohexane-based gel, was also annealed in ammonia to deduce which method is more efficient for N-doping: gel or powder annealing. The post-annealing in air after annealing in ammonia was optimized to attain the best photocatalytic activity for dye degradation under simulated visible light. The size of anatase nanocrystals decreased by doping and the specific surface area of the powders increased. The XPS analysis confirmed a successful substitution of Ti4+ by S(4+) and/or S(6+), which caused a very small band-gap narrowing. The gel annealing in ammonia was much more efficient for interstitial nitrogen incorporation in TiO2 lattice than the powder annealing. The annealing in ammonia of the gel synthesized with dimethyl sulfoxide provided the highest visible-light activity owing to high specific surface area, appropriate mesoporosity and high photoabsorption due to efficient N,S co-doping.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route
EP  - 16728
IS  - 15
SP  - 16718
VL  - 42
DO  - 10.1016/j.ceramint.2016.07.144
ER  - 
@article{
author = "Albrbar, Asma Juma and Djokic, Veljko and Bjelajac, Anđelika and Kovač, Janez and Ćirković, Jovana and Mitrić, Miodrag and Janacković, Đorđe and Petrović, Rada",
year = "2016",
abstract = "Visible-light active mesoporous N,S-doped and co-doped anatase TiO2 powders were synthesized by non-hydrolytic sol-gel route, starting from TiCl4 and Ti((OPr)-Pr-i)(4) dissolved in cyclohexane or dimethyl sulfoxide, later used as a S-doping agent. After drying in an inert atmosphere, the gels were annealed at 500 degrees C for 3 h, in air or ammonia flow, later used for N-doping. The undoped titania powder, obtained by annealing in air of the cyclohexane-based gel, was also annealed in ammonia to deduce which method is more efficient for N-doping: gel or powder annealing. The post-annealing in air after annealing in ammonia was optimized to attain the best photocatalytic activity for dye degradation under simulated visible light. The size of anatase nanocrystals decreased by doping and the specific surface area of the powders increased. The XPS analysis confirmed a successful substitution of Ti4+ by S(4+) and/or S(6+), which caused a very small band-gap narrowing. The gel annealing in ammonia was much more efficient for interstitial nitrogen incorporation in TiO2 lattice than the powder annealing. The annealing in ammonia of the gel synthesized with dimethyl sulfoxide provided the highest visible-light activity owing to high specific surface area, appropriate mesoporosity and high photoabsorption due to efficient N,S co-doping.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route",
pages = "16728-16718",
number = "15",
volume = "42",
doi = "10.1016/j.ceramint.2016.07.144"
}
Albrbar, A. J., Djokic, V., Bjelajac, A., Kovač, J., Ćirković, J., Mitrić, M., Janacković, Đ.,& Petrović, R.. (2016). Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route. in Ceramics International
Elsevier Sci Ltd, Oxford., 42(15), 16718-16728.
https://doi.org/10.1016/j.ceramint.2016.07.144
Albrbar AJ, Djokic V, Bjelajac A, Kovač J, Ćirković J, Mitrić M, Janacković Đ, Petrović R. Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route. in Ceramics International. 2016;42(15):16718-16728.
doi:10.1016/j.ceramint.2016.07.144 .
Albrbar, Asma Juma, Djokic, Veljko, Bjelajac, Anđelika, Kovač, Janez, Ćirković, Jovana, Mitrić, Miodrag, Janacković, Đorđe, Petrović, Rada, "Visible-light active mesoporous, nanocrystalline N,S-doped and co-doped titania photocatalysts synthesized by non-hydrolytic sol-gel route" in Ceramics International, 42, no. 15 (2016):16718-16728,
https://doi.org/10.1016/j.ceramint.2016.07.144 . .
35
21
36

Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution

Jović, Borka M; Lačnjevac, Uroš; Jović, Vladimir D; Gajić-Krstajić, Ljiljana M; Kovač, Janez; Poleti, Dejan; Krstajić, Nedeljko V

(Pergamon-Elsevier Science Ltd, Oxford, 2016)

TY  - JOUR
AU  - Jović, Borka M
AU  - Lačnjevac, Uroš
AU  - Jović, Vladimir D
AU  - Gajić-Krstajić, Ljiljana M
AU  - Kovač, Janez
AU  - Poleti, Dejan
AU  - Krstajić, Nedeljko V
PY  - 2016
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/975
AB  - The oxygen evolution reaction (OER) was studied at pure Ni and Ni-(Ebonex/Ir) composite coatings in 1 M NaOH solution at 25 degrees C. Ni-(Ebonex-supported Ir) coatings were electro-deposited from a nickel Watts bath containing different concentrations of suspended Ebonex/Ir particles (0-2 g dm(-3)) onto a Ni 40 mesh substrate. The surface morphology of the coatings was examined by scanning electron microscopy (SEM), the surface composition by energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRPD) and Xray photoelectron spectroscopy (XPS), whereas the electrochemical properties were studied by electrochemical impedance spectroscopy (EIS), polarization measurements and cyclic voltammetry (CV). It was shown that the roughness factor of Ni-(Ebonex/Ir) composite coatings calculated relative to the surface area of the pure Ni sample increased with the increasing content of Ebonex/Ir particles in the bath to a maximum value of 40.6. All samples displayed a Tafel slope of about 60 mV dec(-1) in the potential range corresponding to lower current densities for the OER. The increase of the apparent activity for the OER at Ni-(Ebonex/Ir) coatings compared with the pure Ni coating was attributed only to the increase of the electrochemically active surface area. Although the pure Ni coating initially exhibited higher intrinsic catalytic activity for the OER than the composite coatings, it also showed a drastic loss of activity after subjecting to continuous oxygen evolution at j = 50 mA cm(-2) for 24 h (Delta E = 395 mV). At the same time, the OER overpotential at Ni-(Ebonex/Ir) coatings only negligibly increased after the stability test (Delta E = 22 mV). The improved retention of catalytic activity observed with Ni-(Ebonex/Ir) coatings was ascribed to the presence of IrO2 which inhibited the formation of the inactive gamma-NiOOH phase.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - International Journal of Hydrogen Energy
T1  - Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution
EP  - 20514
IS  - 45
SP  - 20502
VL  - 41
DO  - 10.1016/j.ijhydene.2016.08.226
ER  - 
@article{
author = "Jović, Borka M and Lačnjevac, Uroš and Jović, Vladimir D and Gajić-Krstajić, Ljiljana M and Kovač, Janez and Poleti, Dejan and Krstajić, Nedeljko V",
year = "2016",
abstract = "The oxygen evolution reaction (OER) was studied at pure Ni and Ni-(Ebonex/Ir) composite coatings in 1 M NaOH solution at 25 degrees C. Ni-(Ebonex-supported Ir) coatings were electro-deposited from a nickel Watts bath containing different concentrations of suspended Ebonex/Ir particles (0-2 g dm(-3)) onto a Ni 40 mesh substrate. The surface morphology of the coatings was examined by scanning electron microscopy (SEM), the surface composition by energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRPD) and Xray photoelectron spectroscopy (XPS), whereas the electrochemical properties were studied by electrochemical impedance spectroscopy (EIS), polarization measurements and cyclic voltammetry (CV). It was shown that the roughness factor of Ni-(Ebonex/Ir) composite coatings calculated relative to the surface area of the pure Ni sample increased with the increasing content of Ebonex/Ir particles in the bath to a maximum value of 40.6. All samples displayed a Tafel slope of about 60 mV dec(-1) in the potential range corresponding to lower current densities for the OER. The increase of the apparent activity for the OER at Ni-(Ebonex/Ir) coatings compared with the pure Ni coating was attributed only to the increase of the electrochemically active surface area. Although the pure Ni coating initially exhibited higher intrinsic catalytic activity for the OER than the composite coatings, it also showed a drastic loss of activity after subjecting to continuous oxygen evolution at j = 50 mA cm(-2) for 24 h (Delta E = 395 mV). At the same time, the OER overpotential at Ni-(Ebonex/Ir) coatings only negligibly increased after the stability test (Delta E = 22 mV). The improved retention of catalytic activity observed with Ni-(Ebonex/Ir) coatings was ascribed to the presence of IrO2 which inhibited the formation of the inactive gamma-NiOOH phase.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "International Journal of Hydrogen Energy",
title = "Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution",
pages = "20514-20502",
number = "45",
volume = "41",
doi = "10.1016/j.ijhydene.2016.08.226"
}
Jović, B. M., Lačnjevac, U., Jović, V. D., Gajić-Krstajić, L. M., Kovač, J., Poleti, D.,& Krstajić, N. V.. (2016). Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution. in International Journal of Hydrogen Energy
Pergamon-Elsevier Science Ltd, Oxford., 41(45), 20502-20514.
https://doi.org/10.1016/j.ijhydene.2016.08.226
Jović BM, Lačnjevac U, Jović VD, Gajić-Krstajić LM, Kovač J, Poleti D, Krstajić NV. Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution. in International Journal of Hydrogen Energy. 2016;41(45):20502-20514.
doi:10.1016/j.ijhydene.2016.08.226 .
Jović, Borka M, Lačnjevac, Uroš, Jović, Vladimir D, Gajić-Krstajić, Ljiljana M, Kovač, Janez, Poleti, Dejan, Krstajić, Nedeljko V, "Ni-(Ebonex-supported Ir) composite coatings as electrocatalysts for alkaline water electrolysis. Part II: Oxygen evolution" in International Journal of Hydrogen Energy, 41, no. 45 (2016):20502-20514,
https://doi.org/10.1016/j.ijhydene.2016.08.226 . .
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36

Ru layers electrodeposited onto highly stable Ti2AlC substrates as cathodes for hydrogen evolution in sulfuric acid solutions

Jović, Borka M; Jović, Vladimir D; Lačnjevac, Uroš; Stevanović, Sanja I.; Kovač, Janez; Radović, M.; Krstajić, Nedeljko V

(Elsevier Science Sa, Lausanne, 2016)

TY  - JOUR
AU  - Jović, Borka M
AU  - Jović, Vladimir D
AU  - Lačnjevac, Uroš
AU  - Stevanović, Sanja I.
AU  - Kovač, Janez
AU  - Radović, M.
AU  - Krstajić, Nedeljko V
PY  - 2016
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/943
AB  - In this work, the hydrogen evolution reaction (HER) was studied on Ru coated Ti2AlC electrodes in 1.0 mol dm(-3) H2SO4 at 25 degrees C. Ti2AlC was found to be a highly stable substrate in sulfuric acid solutions due to the formation of a passivating oxide layer on the surface, which was confirmed by the X-ray photoelectron spectroscopy (XPS) analysis of as-prepared and anodically treated Ti2AlC samples. Ru films were electrodeposited onto Ti2AlC substrates by cycling the potential of Ti2AlC in the solution containing 0.01 mol dm(-3) RuCl3 + 0.1 mol dm(-3) H2SO4 between -0.5 V and 0.4 V vs. a saturated calomel electrode (SCE) at the sweep rate of 20 mV s(-1). Four Ru/Ti2AlC samples were prepared, obtained at 5, 10, 15 and 20 cycles of Ru electrodeposition. Characterization of samples was performed by scanning electron microscopy (SEM) and cyclic voltammetry (CV), while the thickness of the electrodeposited Ru layers was determined by atomic force microscopy (AFM). It was found that the most compact sample with the thickness of about 0.42 mu m was obtained after 5 cycles. Electrochemical impedance spectroscopy (EIS) and steady-state polarization measurements showed that all Ru/Ti2AlC electrodes were exceptionally active for the HER. A Tafel slope of about -60 mV dec(-1) was observed on all polarization curves in the range of high cathodic current densities. Based on formal kinetics analysis, an appropriate mechanism for the HER on Ru/Ti2AlC was suggested.
PB  - Elsevier Science Sa, Lausanne
T2  - Journal of Electroanalytical Chemistry
T1  - Ru layers electrodeposited onto highly stable Ti2AlC substrates as cathodes for hydrogen evolution in sulfuric acid solutions
EP  - 86
SP  - 78
VL  - 766
DO  - 10.1016/j.jelechem.2016.01.038
ER  - 
@article{
author = "Jović, Borka M and Jović, Vladimir D and Lačnjevac, Uroš and Stevanović, Sanja I. and Kovač, Janez and Radović, M. and Krstajić, Nedeljko V",
year = "2016",
abstract = "In this work, the hydrogen evolution reaction (HER) was studied on Ru coated Ti2AlC electrodes in 1.0 mol dm(-3) H2SO4 at 25 degrees C. Ti2AlC was found to be a highly stable substrate in sulfuric acid solutions due to the formation of a passivating oxide layer on the surface, which was confirmed by the X-ray photoelectron spectroscopy (XPS) analysis of as-prepared and anodically treated Ti2AlC samples. Ru films were electrodeposited onto Ti2AlC substrates by cycling the potential of Ti2AlC in the solution containing 0.01 mol dm(-3) RuCl3 + 0.1 mol dm(-3) H2SO4 between -0.5 V and 0.4 V vs. a saturated calomel electrode (SCE) at the sweep rate of 20 mV s(-1). Four Ru/Ti2AlC samples were prepared, obtained at 5, 10, 15 and 20 cycles of Ru electrodeposition. Characterization of samples was performed by scanning electron microscopy (SEM) and cyclic voltammetry (CV), while the thickness of the electrodeposited Ru layers was determined by atomic force microscopy (AFM). It was found that the most compact sample with the thickness of about 0.42 mu m was obtained after 5 cycles. Electrochemical impedance spectroscopy (EIS) and steady-state polarization measurements showed that all Ru/Ti2AlC electrodes were exceptionally active for the HER. A Tafel slope of about -60 mV dec(-1) was observed on all polarization curves in the range of high cathodic current densities. Based on formal kinetics analysis, an appropriate mechanism for the HER on Ru/Ti2AlC was suggested.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Journal of Electroanalytical Chemistry",
title = "Ru layers electrodeposited onto highly stable Ti2AlC substrates as cathodes for hydrogen evolution in sulfuric acid solutions",
pages = "86-78",
volume = "766",
doi = "10.1016/j.jelechem.2016.01.038"
}
Jović, B. M., Jović, V. D., Lačnjevac, U., Stevanović, S. I., Kovač, J., Radović, M.,& Krstajić, N. V.. (2016). Ru layers electrodeposited onto highly stable Ti2AlC substrates as cathodes for hydrogen evolution in sulfuric acid solutions. in Journal of Electroanalytical Chemistry
Elsevier Science Sa, Lausanne., 766, 78-86.
https://doi.org/10.1016/j.jelechem.2016.01.038
Jović BM, Jović VD, Lačnjevac U, Stevanović SI, Kovač J, Radović M, Krstajić NV. Ru layers electrodeposited onto highly stable Ti2AlC substrates as cathodes for hydrogen evolution in sulfuric acid solutions. in Journal of Electroanalytical Chemistry. 2016;766:78-86.
doi:10.1016/j.jelechem.2016.01.038 .
Jović, Borka M, Jović, Vladimir D, Lačnjevac, Uroš, Stevanović, Sanja I., Kovač, Janez, Radović, M., Krstajić, Nedeljko V, "Ru layers electrodeposited onto highly stable Ti2AlC substrates as cathodes for hydrogen evolution in sulfuric acid solutions" in Journal of Electroanalytical Chemistry, 766 (2016):78-86,
https://doi.org/10.1016/j.jelechem.2016.01.038 . .
18
14
19

Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions

Elezović, Nevenka R.; Radmilović, Velimir R; Kovač, Janez; Babić, Biljana M.; Gajić-Krstajić, Ljiljana M; Krstajić, Nedeljko V

(Royal Soc Chemistry, Cambridge, 2015)

TY  - JOUR
AU  - Elezović, Nevenka R.
AU  - Radmilović, Velimir R
AU  - Kovač, Janez
AU  - Babić, Biljana M.
AU  - Gajić-Krstajić, Ljiljana M
AU  - Krstajić, Nedeljko V
PY  - 2015
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/918
AB  - A platinum nanocatalyst on Sb doped tin oxide support (Sb-SnO2) was synthesized and characterized as a catalyst for oxygen reduction reaction in 0.1 mol dm(-3) NaOH solution at 25 degrees C. Sb (5%) doped tin oxide support was synthesized by a modified hydrazine reduction procedure. The platinum nanocatalyst (20% Pt) on Sb-SnO2 support was synthesized by a borohydride reduction method. The synthesized support and catalyst were characterized by high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS) and X-ray diffraction technique (XRD). X-ray photoelectron spectroscopy was applied to characterize the chemical status of elements before and after Pt-treatment. XPS spectra of Sn 3d, Pt 4f, Sb 3d and O 1s revealed that the Pt-deposition on Sb-SnO2 support induced the reduction of the Sn(4+) oxidation state to Sn(2+) and Sn(0) states, while Pt remained in the metallic state and Sb was in the (3+) oxidation state. Homogenous Pt nanoparticle distribution over the support, without pronounced particle agglomeration, was confirmed by HRTEM technique. The average Pt particle size was 2.9 nm. The electrochemically active Pt surface area of the catalyst was determined by the integration of the cyclic voltammetry curve in the potential region of underpotential deposition of hydrogen, after double layer charge correction, taking into account the reference value of 210 mu C cm(-2) for full monolayer coverage. This calculation gave the value of 51 m(2) g(-1). The kinetics of the oxygen reduction reaction with Pt/[Sb-SnO2 catalyst was studied by cyclic voltammetry and linear sweep voltammetry using a rotating gold disc electrode. Two different Tafel slopes were observed: one close to 60 mV dec(-1) in the low current density region, and another at similar to 120 mV dec(-1) in the higher current densities region, as was already referred in previous reports for the oxygen reduction reaction with polycrystalline Pt, as well as with different Pt based nanocatalysts. The specific activities for oxygen reduction, expressed in terms of kinetic current densities per electrochemically Pt active surface area, as well as per mass of Pt loaded, at the constant potential of practical interest (0.85 V and 0.90 V vs. RHE), were compared to a carbon supported (Vulcan XC-72) catalyst. The Pt/[Sb-SnO2 catalyst exhibited similar catalytic activity for oxygen reduction reaction like carbon supported one. The advantages of the carbon free support application in terms of the durability and stability of the catalysts were proved by accelerated stability tests.
PB  - Royal Soc Chemistry, Cambridge
T2  - RSC Advances
T1  - Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions
EP  - 15929
IS  - 21
SP  - 15923
VL  - 5
DO  - 10.1039/c4ra13391a
ER  - 
@article{
author = "Elezović, Nevenka R. and Radmilović, Velimir R and Kovač, Janez and Babić, Biljana M. and Gajić-Krstajić, Ljiljana M and Krstajić, Nedeljko 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.",
publisher = "Royal Soc Chemistry, Cambridge",
journal = "RSC Advances",
title = "Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions",
pages = "15929-15923",
number = "21",
volume = "5",
doi = "10.1039/c4ra13391a"
}
Elezović, N. R., Radmilović, V. R., Kovač, J., Babić, B. M., Gajić-Krstajić, L. M.,& Krstajić, N. V.. (2015). Pt nanoparticles on tin oxide based support as a beneficial catalyst for oxygen reduction in alkaline solutions. in RSC Advances
Royal Soc Chemistry, Cambridge., 5(21), 15923-15929.
https://doi.org/10.1039/c4ra13391a
Elezović NR, Radmilović VR, Kovač J, Babić BM, Gajić-Krstajić LM, Krstajić 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 .
Elezović, Nevenka R., Radmilović, Velimir R, Kovač, Janez, Babić, Biljana M., Gajić-Krstajić, Ljiljana M, Krstajić, Nedeljko 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 . .
1
23
21
23

Synthesis and characterization of Pt nanocatalyst on Ru0.7Ti0.3O2 support as a cathode for fuel cells application

Elezović, Nevenka R.; Ercius, P.; Kovač, Janez; Radmilović, Velimir R; Babić, Biljana M.; Krstajić, Nedeljko V

(Elsevier Science Sa, Lausanne, 2015)

TY  - JOUR
AU  - Elezović, Nevenka R.
AU  - Ercius, P.
AU  - Kovač, Janez
AU  - Radmilović, Velimir R
AU  - Babić, Biljana M.
AU  - Krstajić, Nedeljko V
PY  - 2015
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/895
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.
PB  - Elsevier Science Sa, Lausanne
T2  - Journal of Electroanalytical Chemistry
T1  - Synthesis and characterization of Pt nanocatalyst on Ru0.7Ti0.3O2 support as a cathode for fuel cells application
EP  - 171
SP  - 164
VL  - 739
DO  - 10.1016/j.jelechem.2014.12.033
ER  - 
@article{
author = "Elezović, Nevenka R. and Ercius, P. and Kovač, Janez and Radmilović, Velimir R and Babić, Biljana M. and Krstajić, Nedeljko 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.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Journal of Electroanalytical Chemistry",
title = "Synthesis and characterization of Pt nanocatalyst on Ru0.7Ti0.3O2 support as a cathode for fuel cells application",
pages = "171-164",
volume = "739",
doi = "10.1016/j.jelechem.2014.12.033"
}
Elezović, N. R., Ercius, P., Kovač, J., Radmilović, V. R., Babić, B. M.,& Krstajić, 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
Elsevier Science Sa, Lausanne., 739, 164-171.
https://doi.org/10.1016/j.jelechem.2014.12.033
Elezović NR, Ercius P, Kovač J, Radmilović VR, Babić BM, Krstajić 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 .
Elezović, Nevenka R., Ercius, P., Kovač, Janez, Radmilović, Velimir R, Babić, Biljana M., Krstajić, Nedeljko 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 . .
5
4
5

Ti substrate coated with composite Cr-MoO2 coatings as highly selective cathode materials in hypochlorite production

Lačnjevac, Uroš; Jović, Borka M; Gajić-Krstajić, Ljiljana M; Kovač, Janez; Jović, Vladimir D; Krstajić, Nedeljko V

(Pergamon-Elsevier Science Ltd, Oxford, 2013)

TY  - JOUR
AU  - Lačnjevac, Uroš
AU  - Jović, Borka M
AU  - Gajić-Krstajić, Ljiljana M
AU  - Kovač, Janez
AU  - Jović, Vladimir D
AU  - Krstajić, Nedeljko V
PY  - 2013
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/669
AB  - The aim of this work was to investigate the possibility of preparation of the composite Cr-MoO2 coatings onto steel and titanium substrates as cathode materials with high selective properties which imply the suppression of hypochlorite reduction as a side reaction during hypochlorite commercial production. The electrodes were prepared by simultaneous deposition of chromium and suspended MoO2 particles on titanium substrate from acid chromium (VI) bath. The current efficiency for electrodeposition of the composite coatings did not vary significantly with the concentration of suspended MoO2 particles. The content of molybdenum in the deposits was relatively low (0.2-1.5 at.%) and increased with increasing the concentration of suspended MoO2 particles in the bath, in the range from 0 to 10 g dm(-3). With further increase in the concentration of MoO2, the content of molybdenum in the coating varied insignificantly. X-ray photoelectron spectroscopy-XPS and EDS analysis were applied to analyze elemental composition and chemical bonding of elements on the surface and in the sub-surface region of obtained coatings. When the concentration of MoO2 particles in the bath was raised above 5 g dm(-3), the appearance of the coating changed from the typical pure chromium deposit to needle-like deposit with the appearance of black inclusions on the surface. XPS analysis and corresponding Cr 2p spectra showed the presence of chromium oxide, probably Cr2O3 with Cr(3+) valence state on the surface and in the sub-surface region of Cr-MoO2 coatings. Investigation of the current efficiency for the hydrogen evolution reaction (HER) on Cr-MoO2 cathodes showed that it increased with the increase of the content of MoO2 particles in the coating, exceeding the value of 97% in the solution with the hypochlorite concentration of 0.21 mol dm(-3). Under the same conditions, the current efficiency for the HER on Ti and Ti/Cr cathodes is very low (approximate to 20%), and corresponding polarization curves confirmed the fact that the side reaction of hypochlorite reduction takes place in the diffusion-controlled regime on these electrodes. The high selectivity of Cr-MoO2 coating is probably caused by the presence of chromium oxide (hydroxide) formed at the surface of the coating during co-deposition of Cr and MoO2 particles, which prevents hypochlorite reduction on the cathode during the HER.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Electrochimica Acta
T1  - Ti substrate coated with composite Cr-MoO2 coatings as highly selective cathode materials in hypochlorite production
EP  - 42
SP  - 34
VL  - 96
DO  - 10.1016/j.electacta.2013.02.086
ER  - 
@article{
author = "Lačnjevac, Uroš and Jović, Borka M and Gajić-Krstajić, Ljiljana M and Kovač, Janez and Jović, Vladimir D and Krstajić, Nedeljko V",
year = "2013",
abstract = "The aim of this work was to investigate the possibility of preparation of the composite Cr-MoO2 coatings onto steel and titanium substrates as cathode materials with high selective properties which imply the suppression of hypochlorite reduction as a side reaction during hypochlorite commercial production. The electrodes were prepared by simultaneous deposition of chromium and suspended MoO2 particles on titanium substrate from acid chromium (VI) bath. The current efficiency for electrodeposition of the composite coatings did not vary significantly with the concentration of suspended MoO2 particles. The content of molybdenum in the deposits was relatively low (0.2-1.5 at.%) and increased with increasing the concentration of suspended MoO2 particles in the bath, in the range from 0 to 10 g dm(-3). With further increase in the concentration of MoO2, the content of molybdenum in the coating varied insignificantly. X-ray photoelectron spectroscopy-XPS and EDS analysis were applied to analyze elemental composition and chemical bonding of elements on the surface and in the sub-surface region of obtained coatings. When the concentration of MoO2 particles in the bath was raised above 5 g dm(-3), the appearance of the coating changed from the typical pure chromium deposit to needle-like deposit with the appearance of black inclusions on the surface. XPS analysis and corresponding Cr 2p spectra showed the presence of chromium oxide, probably Cr2O3 with Cr(3+) valence state on the surface and in the sub-surface region of Cr-MoO2 coatings. Investigation of the current efficiency for the hydrogen evolution reaction (HER) on Cr-MoO2 cathodes showed that it increased with the increase of the content of MoO2 particles in the coating, exceeding the value of 97% in the solution with the hypochlorite concentration of 0.21 mol dm(-3). Under the same conditions, the current efficiency for the HER on Ti and Ti/Cr cathodes is very low (approximate to 20%), and corresponding polarization curves confirmed the fact that the side reaction of hypochlorite reduction takes place in the diffusion-controlled regime on these electrodes. The high selectivity of Cr-MoO2 coating is probably caused by the presence of chromium oxide (hydroxide) formed at the surface of the coating during co-deposition of Cr and MoO2 particles, which prevents hypochlorite reduction on the cathode during the HER.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Electrochimica Acta",
title = "Ti substrate coated with composite Cr-MoO2 coatings as highly selective cathode materials in hypochlorite production",
pages = "42-34",
volume = "96",
doi = "10.1016/j.electacta.2013.02.086"
}
Lačnjevac, U., Jović, B. M., Gajić-Krstajić, L. M., Kovač, J., Jović, V. D.,& Krstajić, N. V.. (2013). Ti substrate coated with composite Cr-MoO2 coatings as highly selective cathode materials in hypochlorite production. in Electrochimica Acta
Pergamon-Elsevier Science Ltd, Oxford., 96, 34-42.
https://doi.org/10.1016/j.electacta.2013.02.086
Lačnjevac U, Jović BM, Gajić-Krstajić LM, Kovač J, Jović VD, Krstajić NV. Ti substrate coated with composite Cr-MoO2 coatings as highly selective cathode materials in hypochlorite production. in Electrochimica Acta. 2013;96:34-42.
doi:10.1016/j.electacta.2013.02.086 .
Lačnjevac, Uroš, Jović, Borka M, Gajić-Krstajić, Ljiljana M, Kovač, Janez, Jović, Vladimir D, Krstajić, Nedeljko V, "Ti substrate coated with composite Cr-MoO2 coatings as highly selective cathode materials in hypochlorite production" in Electrochimica Acta, 96 (2013):34-42,
https://doi.org/10.1016/j.electacta.2013.02.086 . .
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