Kratovac, Marija

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  • Kratovac, Marija (2)
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Author's Bibliography

Investigation of hydrogen evolution reaction on ZnO/rGO

Kratovac, Marija; Aleksić, Katarina; Marković, Smilja; Stojković Simatović, Ivana

(Belgrade : Serbian Chemical Society, 2023)

TY  - CONF
AU  - Kratovac, Marija
AU  - Aleksić, Katarina
AU  - Marković, Smilja
AU  - Stojković Simatović, Ivana
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16166
UR  - https://www.shd.org.rs/wp-content/uploads/2023/11/9CYCS_Book-of-Abstracts.pdf
AB  - The hydrogen evolution reaction (HER) is one of the indispensable parts of the water splitting process and is increasingly being researched [1]. The main goal of this study was to enhance the electrochemical properties of nanostructured zinc oxide (ZnO) particles toward HER. In order to enhance their electrochemical properties, ZnO nanoparticles were precipitated onto graphene oxide (GO) to form a ZnO/GO composite which was in situ reduced before electrochemical measurements toward HER.
A composite of ZnO/GO (0.1 and 0.5 wt.%) was synthesized using a microwave processing of a precipitate. X-ray diffraction analysis (XRD), Raman spectroscopy, and field emission scanning electron microscopy (FESEM) were used to investigate the structural and morphological characteristics of composite materials. The diffractograms showed narrow reflections with relatively high intensities, which implies high crystallinity of composite materials. Raman spectra of ZnO/GO_0.5 shows a higher intensity D- and G-bands, attributed to GO, than ZnO/GO_0.1 confirming a larger amount of graphene oxide. FESEM images of composite samples show nanostructured particles. Before HER measurements, the electrode prepared by a mixture of ZnO/GO composite, nafion and ethanol/water solvent, was in situ reduced at potential -1.4 V in 0.1 M KCl to get ZnO/rGO. HER activity was investigated in NaOH by linear voltammetry. ZnO/rGO_0.5 showed increased electrochemical activity as a result of the evolution of hydrogen starting earlier and the higher current density.
PB  - Belgrade : Serbian Chemical Society
PB  - Belgrade : Serbian Young Chemists Club
C3  - Book of abstracts / 9th Conference of the Young Chemists of Serbia, 4th November 2023, Novi Sad
T1  - Investigation of hydrogen evolution reaction on ZnO/rGO
SP  - 114
EP  - 114
UR  - https://hdl.handle.net/21.15107/rcub_dais_16166
ER  - 
@conference{
author = "Kratovac, Marija and Aleksić, Katarina and Marković, Smilja and Stojković Simatović, Ivana",
year = "2023",
abstract = "The hydrogen evolution reaction (HER) is one of the indispensable parts of the water splitting process and is increasingly being researched [1]. The main goal of this study was to enhance the electrochemical properties of nanostructured zinc oxide (ZnO) particles toward HER. In order to enhance their electrochemical properties, ZnO nanoparticles were precipitated onto graphene oxide (GO) to form a ZnO/GO composite which was in situ reduced before electrochemical measurements toward HER.
A composite of ZnO/GO (0.1 and 0.5 wt.%) was synthesized using a microwave processing of a precipitate. X-ray diffraction analysis (XRD), Raman spectroscopy, and field emission scanning electron microscopy (FESEM) were used to investigate the structural and morphological characteristics of composite materials. The diffractograms showed narrow reflections with relatively high intensities, which implies high crystallinity of composite materials. Raman spectra of ZnO/GO_0.5 shows a higher intensity D- and G-bands, attributed to GO, than ZnO/GO_0.1 confirming a larger amount of graphene oxide. FESEM images of composite samples show nanostructured particles. Before HER measurements, the electrode prepared by a mixture of ZnO/GO composite, nafion and ethanol/water solvent, was in situ reduced at potential -1.4 V in 0.1 M KCl to get ZnO/rGO. HER activity was investigated in NaOH by linear voltammetry. ZnO/rGO_0.5 showed increased electrochemical activity as a result of the evolution of hydrogen starting earlier and the higher current density.",
publisher = "Belgrade : Serbian Chemical Society, Belgrade : Serbian Young Chemists Club",
journal = "Book of abstracts / 9th Conference of the Young Chemists of Serbia, 4th November 2023, Novi Sad",
title = "Investigation of hydrogen evolution reaction on ZnO/rGO",
pages = "114-114",
url = "https://hdl.handle.net/21.15107/rcub_dais_16166"
}
Kratovac, M., Aleksić, K., Marković, S.,& Stojković Simatović, I.. (2023). Investigation of hydrogen evolution reaction on ZnO/rGO. in Book of abstracts / 9th Conference of the Young Chemists of Serbia, 4th November 2023, Novi Sad
Belgrade : Serbian Chemical Society., 114-114.
https://hdl.handle.net/21.15107/rcub_dais_16166
Kratovac M, Aleksić K, Marković S, Stojković Simatović I. Investigation of hydrogen evolution reaction on ZnO/rGO. in Book of abstracts / 9th Conference of the Young Chemists of Serbia, 4th November 2023, Novi Sad. 2023;:114-114.
https://hdl.handle.net/21.15107/rcub_dais_16166 .
Kratovac, Marija, Aleksić, Katarina, Marković, Smilja, Stojković Simatović, Ivana, "Investigation of hydrogen evolution reaction on ZnO/rGO" in Book of abstracts / 9th Conference of the Young Chemists of Serbia, 4th November 2023, Novi Sad (2023):114-114,
https://hdl.handle.net/21.15107/rcub_dais_16166 .

Electrochemical detection of chloramphenicol drug based on ZnO and ZnO/graphene oxide composite nanoparticles

Stanković, Ana; Aleksić, Katarina; Kratovac, Marija; Stojković Simatović, Ivana; Kraljić Rokvić, Marijana; Marković, Smilja

(Belgrade : Materials Research Society of Serbia, 2023)

TY  - CONF
AU  - Stanković, Ana
AU  - Aleksić, Katarina
AU  - Kratovac, Marija
AU  - Stojković Simatović, Ivana
AU  - Kraljić Rokvić, Marijana
AU  - Marković, Smilja
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14870
AB  - The release of pharmaceuticals in the environment represents a significant ecological problem due to their complex structure making them challenge to be decomposed and removed by standard waste-water treatment processes. Zinc oxide (ZnO) represents a semiconductor compound with exceptional optical and electrochemical properties, chemical and photochemical stability, nontoxicity, biocompatibility, etc. Due to their adjustable multifunctional properties, ZnO based materials have concerned general scientific and technological attention. Nowadays these materials are used for a range of applications in electronics, opto-electronics, biosensing, bioimaging, drug delivery, antimicrobial and anticancer agents, implants as well as sensing in environmental applications. The main object of this study was to improve efficiency of ZnO particles toward electrochemical sensing of water pollutants and electrocatalysis. In order to modify electrochemical properties, zinc oxide/graphene oxide (ZnO/GO) composites with different ZnO:GO weights ratio were prepared using a microwave (MW) assisted synthesis of precipitate. Two different amounts of GO (0.1 and 0.5 wt.%) were dispersed in 100 mL of distilled water. After stirring for 5 min an appropriate amount of ZnCl2 was added to the GO water dispersion. Subsequently, 20 mL of 1.75 M NaOH was added dropwise to the mixture with constant stirring. After being stirred at 50 C for 90 min in total, the as-prepared precipitate was microwave processed in a MW oven (2.45 GHz, 130 W) for 5 min. After cooling to room temperature, the precipitate was centrifuged and rinsed to remove the surface residues of the starting chemical solutions. The synthesized powder was dried in an oven at 80 C for 24 h. The particles crystal structure and phase composition were investigated by X-ray diffraction and Raman spectroscopy. The particles morphology was determined with FE–SEM. The optical properties were studied using UV–Vis DRS and PL spectroscopy. The electrochemical sensing activity of ZnO and ZnO/GO electrodes was tested for detection of chloramphenicol water solution whereas electrocatalytic activity was tested for water splitting when samples were used as anode materials and evaluated by linear sweep voltammetry in 0.1M NaOH and 0.1 M H2SO4 electrolytes. ZnO/GO electrodes were tested as-prepared and after in situ reduction of GO at -1.4 V vs. SCE in 0.1 M KCl. Electrochemical activity of prepared composites was correlated with the presence of GO and reduced GO particles.
PB  - Belgrade : Materials Research Society of Serbia
C3  - Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023
T1  - Electrochemical detection of chloramphenicol drug based on ZnO and ZnO/graphene oxide composite nanoparticles
SP  - 155
EP  - 155
UR  - https://hdl.handle.net/21.15107/rcub_dais_14870
ER  - 
@conference{
author = "Stanković, Ana and Aleksić, Katarina and Kratovac, Marija and Stojković Simatović, Ivana and Kraljić Rokvić, Marijana and Marković, Smilja",
year = "2023",
abstract = "The release of pharmaceuticals in the environment represents a significant ecological problem due to their complex structure making them challenge to be decomposed and removed by standard waste-water treatment processes. Zinc oxide (ZnO) represents a semiconductor compound with exceptional optical and electrochemical properties, chemical and photochemical stability, nontoxicity, biocompatibility, etc. Due to their adjustable multifunctional properties, ZnO based materials have concerned general scientific and technological attention. Nowadays these materials are used for a range of applications in electronics, opto-electronics, biosensing, bioimaging, drug delivery, antimicrobial and anticancer agents, implants as well as sensing in environmental applications. The main object of this study was to improve efficiency of ZnO particles toward electrochemical sensing of water pollutants and electrocatalysis. In order to modify electrochemical properties, zinc oxide/graphene oxide (ZnO/GO) composites with different ZnO:GO weights ratio were prepared using a microwave (MW) assisted synthesis of precipitate. Two different amounts of GO (0.1 and 0.5 wt.%) were dispersed in 100 mL of distilled water. After stirring for 5 min an appropriate amount of ZnCl2 was added to the GO water dispersion. Subsequently, 20 mL of 1.75 M NaOH was added dropwise to the mixture with constant stirring. After being stirred at 50 C for 90 min in total, the as-prepared precipitate was microwave processed in a MW oven (2.45 GHz, 130 W) for 5 min. After cooling to room temperature, the precipitate was centrifuged and rinsed to remove the surface residues of the starting chemical solutions. The synthesized powder was dried in an oven at 80 C for 24 h. The particles crystal structure and phase composition were investigated by X-ray diffraction and Raman spectroscopy. The particles morphology was determined with FE–SEM. The optical properties were studied using UV–Vis DRS and PL spectroscopy. The electrochemical sensing activity of ZnO and ZnO/GO electrodes was tested for detection of chloramphenicol water solution whereas electrocatalytic activity was tested for water splitting when samples were used as anode materials and evaluated by linear sweep voltammetry in 0.1M NaOH and 0.1 M H2SO4 electrolytes. ZnO/GO electrodes were tested as-prepared and after in situ reduction of GO at -1.4 V vs. SCE in 0.1 M KCl. Electrochemical activity of prepared composites was correlated with the presence of GO and reduced GO particles.",
publisher = "Belgrade : Materials Research Society of Serbia",
journal = "Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023",
title = "Electrochemical detection of chloramphenicol drug based on ZnO and ZnO/graphene oxide composite nanoparticles",
pages = "155-155",
url = "https://hdl.handle.net/21.15107/rcub_dais_14870"
}
Stanković, A., Aleksić, K., Kratovac, M., Stojković Simatović, I., Kraljić Rokvić, M.,& Marković, S.. (2023). Electrochemical detection of chloramphenicol drug based on ZnO and ZnO/graphene oxide composite nanoparticles. in Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023
Belgrade : Materials Research Society of Serbia., 155-155.
https://hdl.handle.net/21.15107/rcub_dais_14870
Stanković A, Aleksić K, Kratovac M, Stojković Simatović I, Kraljić Rokvić M, Marković S. Electrochemical detection of chloramphenicol drug based on ZnO and ZnO/graphene oxide composite nanoparticles. in Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023. 2023;:155-155.
https://hdl.handle.net/21.15107/rcub_dais_14870 .
Stanković, Ana, Aleksić, Katarina, Kratovac, Marija, Stojković Simatović, Ivana, Kraljić Rokvić, Marijana, Marković, Smilja, "Electrochemical detection of chloramphenicol drug based on ZnO and ZnO/graphene oxide composite nanoparticles" in Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023 (2023):155-155,
https://hdl.handle.net/21.15107/rcub_dais_14870 .