TY  - JOUR
AU  - Vojisavljević, Katarina
AU  - Wicker, Susanne
AU  - Can, Inci
AU  - Bencan, Andreja
AU  - Barsan, Nicolae
AU  - Malic, Barbara
PY  - 2017
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1038
AB  - The present study demonstrates the relationship between the combustion reaction mechanism induced by the exothermicity of the cobalt nitrate-glycine solution-combustion reactions and morphological details of the nanocrystalline Co3O4. The thermal decomposition pathway and the amount of the heat liberated in combustion are defined by the exothermic reaction between gaseous NH3 and N2O species. A direct evidence that the exothermicity of the combustion reaction plays an important role in formation of the powders with different morphology was obtained from the scanning and transmission electron microscopies. In contrast to stoichiometric reaction, where the short-string Co3O4 particles form hard agglomerates, the energetically softer 50% fuel lean reaction is responsible for weak bonds between Co3O4 particles and formation of the loose cauliflower-like agglomerates. The latter powder with the specific surface area of 64.4 m(2)/g and the average crystallite size of similar to 11 nm was used for the processing of drop-coated sensors, which showed a superior sensor response toward 20 ppm of acetone in 25% r.h. humidity and at low operating temperature of 150 degrees C.
PB  - Elsevier Science Bv, Amsterdam
T2  - Advanced Powder Technology
T1  - Nanocrystalline cobalt-oxide powders by solution-combustion synthesis and their application in chemical sensors
EP  - 1128
IS  - 4
SP  - 1118
VL  - 28
DO  - 10.1016/j.apt.2016.10.029
ER  - 

@article{
author = "Vojisavljević, Katarina and Wicker, Susanne and Can, Inci and Bencan, Andreja and Barsan, Nicolae and Malic, Barbara",
year = "2017",
abstract = "The present study demonstrates the relationship between the combustion reaction mechanism induced by the exothermicity of the cobalt nitrate-glycine solution-combustion reactions and morphological details of the nanocrystalline Co3O4. The thermal decomposition pathway and the amount of the heat liberated in combustion are defined by the exothermic reaction between gaseous NH3 and N2O species. A direct evidence that the exothermicity of the combustion reaction plays an important role in formation of the powders with different morphology was obtained from the scanning and transmission electron microscopies. In contrast to stoichiometric reaction, where the short-string Co3O4 particles form hard agglomerates, the energetically softer 50% fuel lean reaction is responsible for weak bonds between Co3O4 particles and formation of the loose cauliflower-like agglomerates. The latter powder with the specific surface area of 64.4 m(2)/g and the average crystallite size of similar to 11 nm was used for the processing of drop-coated sensors, which showed a superior sensor response toward 20 ppm of acetone in 25% r.h. humidity and at low operating temperature of 150 degrees C.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Advanced Powder Technology",
title = "Nanocrystalline cobalt-oxide powders by solution-combustion synthesis and their application in chemical sensors",
pages = "1128-1118",
number = "4",
volume = "28",
doi = "10.1016/j.apt.2016.10.029"
}

Vojisavljević, K., Wicker, S., Can, I., Bencan, A., Barsan, N.,& Malic, B.. (2017). Nanocrystalline cobalt-oxide powders by solution-combustion synthesis and their application in chemical sensors. in Advanced Powder Technology
Elsevier Science Bv, Amsterdam., 28(4), 1118-1128.
https://doi.org/10.1016/j.apt.2016.10.029

Vojisavljević K, Wicker S, Can I, Bencan A, Barsan N, Malic B. Nanocrystalline cobalt-oxide powders by solution-combustion synthesis and their application in chemical sensors. in Advanced Powder Technology. 2017;28(4):1118-1128.
doi:10.1016/j.apt.2016.10.029 .

Vojisavljević, Katarina, Wicker, Susanne, Can, Inci, Bencan, Andreja, Barsan, Nicolae, Malic, Barbara, "Nanocrystalline cobalt-oxide powders by solution-combustion synthesis and their application in chemical sensors" in Advanced Powder Technology, 28, no. 4 (2017):1118-1128,
https://doi.org/10.1016/j.apt.2016.10.029 . .

TY  - CONF
AU  - Vojisavljević, Katarina
AU  - Wicker, Susanne
AU  - Barsan, Nicolae
AU  - Kmet, Brigita
AU  - Drnovšek, Silvo
AU  - Malič, Barbara
PY  - 2014
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2914
AB  - Cobalt oxide, Co3O4, which is known as a good CO catalyst, has in the past decade also drawn some research interest as a p-type metal oxide gas sensor. A powerful strategy to improve the sensor performance is the utilization of a nanocrystalline powder with a high surface to volume ratio. Thus, a strong interaction between the surrounding gas and the sensor material is enabled.
The nanocrystalline Co3O4 powder was synthesised by the nitrate-glycine self-sustained combustion route. The glycine/metal ion ratio was adjusted to provide stoichiometric or fuel-lean conditions of the redox reaction. During the rapid heating, the gels auto-ignited at approximately 250 oC (depending on the amount of the fuel) and spontaneously underwent a smouldering combustion with the evolution of large amounts of gases, subsequently forming a voluminous precursor powder. According to the X-ray diffraction analysis the phase-pure Co3O4 was obtained only when the precursor powder was prepared from the fuel-lean redox reaction. The field emission scanning electron micrographs revealed the spongy aspect of the calcined powder, where small primary particles formed the agglomerates. 
For the screen-printing, the Co3O4 powder was milled to break the agglomerates, and then mixed with the organic binder to achieve a viscous paste suitable for printing. The paste was screen printed onto Al2O3 substrates with interdigitated Pt electrodes for read-out of the resistance and a Pt heater for operation at well controlled temperatures, on the front and back-sides respectively. The about 50 µm thick films were fired at 400 oC in air. The phase composition was analysed by X-ray diffraction analysis and Fourier transformed infrared spectroscopy. The catalytic conversion of the Co3O4 powder and the sensor signal of the corresponding sensors were checked under different concentrations of the CO, CH4 and C2H5OH test gases.
PB  - Edition of Electromeramics Conference
C3  - Electroceramics XIV Conference 2014
T1  - Preparation of nanocrystalline Co3O4 powder and processing of thick films for sensor application
EP  - 17
SP  - 17
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2914
ER  - 

@conference{
author = "Vojisavljević, Katarina and Wicker, Susanne and Barsan, Nicolae and Kmet, Brigita and Drnovšek, Silvo and Malič, Barbara",
year = "2014",
abstract = "Cobalt oxide, Co3O4, which is known as a good CO catalyst, has in the past decade also drawn some research interest as a p-type metal oxide gas sensor. A powerful strategy to improve the sensor performance is the utilization of a nanocrystalline powder with a high surface to volume ratio. Thus, a strong interaction between the surrounding gas and the sensor material is enabled.
The nanocrystalline Co3O4 powder was synthesised by the nitrate-glycine self-sustained combustion route. The glycine/metal ion ratio was adjusted to provide stoichiometric or fuel-lean conditions of the redox reaction. During the rapid heating, the gels auto-ignited at approximately 250 oC (depending on the amount of the fuel) and spontaneously underwent a smouldering combustion with the evolution of large amounts of gases, subsequently forming a voluminous precursor powder. According to the X-ray diffraction analysis the phase-pure Co3O4 was obtained only when the precursor powder was prepared from the fuel-lean redox reaction. The field emission scanning electron micrographs revealed the spongy aspect of the calcined powder, where small primary particles formed the agglomerates. 
For the screen-printing, the Co3O4 powder was milled to break the agglomerates, and then mixed with the organic binder to achieve a viscous paste suitable for printing. The paste was screen printed onto Al2O3 substrates with interdigitated Pt electrodes for read-out of the resistance and a Pt heater for operation at well controlled temperatures, on the front and back-sides respectively. The about 50 µm thick films were fired at 400 oC in air. The phase composition was analysed by X-ray diffraction analysis and Fourier transformed infrared spectroscopy. The catalytic conversion of the Co3O4 powder and the sensor signal of the corresponding sensors were checked under different concentrations of the CO, CH4 and C2H5OH test gases.",
publisher = "Edition of Electromeramics Conference",
journal = "Electroceramics XIV Conference 2014",
title = "Preparation of nanocrystalline Co3O4 powder and processing of thick films for sensor application",
pages = "17-17",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2914"
}

Vojisavljević, K., Wicker, S., Barsan, N., Kmet, B., Drnovšek, S.,& Malič, B.. (2014). Preparation of nanocrystalline Co3O4 powder and processing of thick films for sensor application. in Electroceramics XIV Conference 2014
Edition of Electromeramics Conference., 17-17.
https://hdl.handle.net/21.15107/rcub_rimsi_2914

Vojisavljević K, Wicker S, Barsan N, Kmet B, Drnovšek S, Malič B. Preparation of nanocrystalline Co3O4 powder and processing of thick films for sensor application. in Electroceramics XIV Conference 2014. 2014;:17-17.
https://hdl.handle.net/21.15107/rcub_rimsi_2914 .

Vojisavljević, Katarina, Wicker, Susanne, Barsan, Nicolae, Kmet, Brigita, Drnovšek, Silvo, Malič, Barbara, "Preparation of nanocrystalline Co3O4 powder and processing of thick films for sensor application" in Electroceramics XIV Conference 2014 (2014):17-17,
https://hdl.handle.net/21.15107/rcub_rimsi_2914 .

TY  - CONF
AU  - Vojisavljević, Katarina
AU  - Wicker, Susanne
AU  - Barsan, Nicolae
AU  - Kmet, Brigita
AU  - Drnovšek, Silvo
AU  - Malič, Barbara
PY  - 2014
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/2909
AB  - Cobalt oxide, Co3O4, has shown great potentials for various practical applications due to excellent
electronic, magnetic and redox properties. Its high catalytic activity in combustion of CO is well
known for a longer period. However, this material has also drawn some research interest as a p-type
metal oxide gas sensor. A powerful strategy to improve both catalytic and sensor performance is the
utilization of a nanocrystalline powder with a high surface to volume ratio. Thus, a strong interaction
between the surrounding gas and the material is enabled.
The nanocrystalline Co3O4 powder was synthesised by the nitrate-glycine combustion route. The
glycine/metal ion ratio was adjusted to provide stoichiometric or fuel-lean conditions of the redox
reaction. The auto-ignition of gels with the evolution of large amounts of gases was occurred at
approximately 180 °C, and the process was spontaneously underwent to a smouldering combustion
and formation of a voluminous powder. According to the X-ray diffraction analysis the phase-pure
Co3O4 was obtained only when the precursor powder was prepared from the 50% fuel-lean redox
reaction. The field emission scanning electron micrographs revealed the spongy aspect of the calcined
powder, where small primary particles formed the agglomerates.
For the screen-printing, the Co3O4 powder was mixed with the organic binder to achieve a viscous
paste suitable for printing. The paste was screen printed onto Al2O3 substrates with interdigitated Pt
electrodes for read-out of the resistance and a Pt heater for operation at well controlled temperatures,
and fired at 400 °C in air. The catalytic conversion of the Co3O4 powder and the sensor signal of the
corresponding sensors were checked under different concentrations of the reducing test gases. The
excellent catalytic activity of the Co3O4 powder was confirmed. The sensor signal was the best to
ethanol at the operating temperature of 150 °C, which was found to be 100 °C lower than for comercial
SnO2 sensors.
PB  - In{titut za kovinske materiale in tehnologije, Ljubljana, Lepi pot 11, Ljubljana, Slovenija
C3  - 22nd INTERNATIONAL CONFERENCE ON MATERIALS AND TECHNOLOGY
T1  - CATALYTIC AND SENSOR PROPERTIES OF Co3O4 PREPARED BY COMBUSTION SYNTHESIS ROUTE
EP  - 246
SP  - 246
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_2909
ER  - 

@conference{
author = "Vojisavljević, Katarina and Wicker, Susanne and Barsan, Nicolae and Kmet, Brigita and Drnovšek, Silvo and Malič, Barbara",
year = "2014",
abstract = "Cobalt oxide, Co3O4, has shown great potentials for various practical applications due to excellent
electronic, magnetic and redox properties. Its high catalytic activity in combustion of CO is well
known for a longer period. However, this material has also drawn some research interest as a p-type
metal oxide gas sensor. A powerful strategy to improve both catalytic and sensor performance is the
utilization of a nanocrystalline powder with a high surface to volume ratio. Thus, a strong interaction
between the surrounding gas and the material is enabled.
The nanocrystalline Co3O4 powder was synthesised by the nitrate-glycine combustion route. The
glycine/metal ion ratio was adjusted to provide stoichiometric or fuel-lean conditions of the redox
reaction. The auto-ignition of gels with the evolution of large amounts of gases was occurred at
approximately 180 °C, and the process was spontaneously underwent to a smouldering combustion
and formation of a voluminous powder. According to the X-ray diffraction analysis the phase-pure
Co3O4 was obtained only when the precursor powder was prepared from the 50% fuel-lean redox
reaction. The field emission scanning electron micrographs revealed the spongy aspect of the calcined
powder, where small primary particles formed the agglomerates.
For the screen-printing, the Co3O4 powder was mixed with the organic binder to achieve a viscous
paste suitable for printing. The paste was screen printed onto Al2O3 substrates with interdigitated Pt
electrodes for read-out of the resistance and a Pt heater for operation at well controlled temperatures,
and fired at 400 °C in air. The catalytic conversion of the Co3O4 powder and the sensor signal of the
corresponding sensors were checked under different concentrations of the reducing test gases. The
excellent catalytic activity of the Co3O4 powder was confirmed. The sensor signal was the best to
ethanol at the operating temperature of 150 °C, which was found to be 100 °C lower than for comercial
SnO2 sensors.",
publisher = "In{titut za kovinske materiale in tehnologije, Ljubljana, Lepi pot 11, Ljubljana, Slovenija",
journal = "22nd INTERNATIONAL CONFERENCE ON MATERIALS AND TECHNOLOGY",
title = "CATALYTIC AND SENSOR PROPERTIES OF Co3O4 PREPARED BY COMBUSTION SYNTHESIS ROUTE",
pages = "246-246",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2909"
}

Vojisavljević, K., Wicker, S., Barsan, N., Kmet, B., Drnovšek, S.,& Malič, B.. (2014). CATALYTIC AND SENSOR PROPERTIES OF Co3O4 PREPARED BY COMBUSTION SYNTHESIS ROUTE. in 22nd INTERNATIONAL CONFERENCE ON MATERIALS AND TECHNOLOGY
In{titut za kovinske materiale in tehnologije, Ljubljana, Lepi pot 11, Ljubljana, Slovenija., 246-246.
https://hdl.handle.net/21.15107/rcub_rimsi_2909

Vojisavljević K, Wicker S, Barsan N, Kmet B, Drnovšek S, Malič B. CATALYTIC AND SENSOR PROPERTIES OF Co3O4 PREPARED BY COMBUSTION SYNTHESIS ROUTE. in 22nd INTERNATIONAL CONFERENCE ON MATERIALS AND TECHNOLOGY. 2014;:246-246.
https://hdl.handle.net/21.15107/rcub_rimsi_2909 .

Vojisavljević, Katarina, Wicker, Susanne, Barsan, Nicolae, Kmet, Brigita, Drnovšek, Silvo, Malič, Barbara, "CATALYTIC AND SENSOR PROPERTIES OF Co3O4 PREPARED BY COMBUSTION SYNTHESIS ROUTE" in 22nd INTERNATIONAL CONFERENCE ON MATERIALS AND TECHNOLOGY (2014):246-246,
https://hdl.handle.net/21.15107/rcub_rimsi_2909 .