Maksym Zahornyi | Frantsevich Institute for Problems of Materials Science, NAS of Ukraine (original) (raw)

Papers by Maksym Zahornyi

Journal of chemistry and technologies, Oct 11, 2019

The influence of BaTiO3 nanopowder dispersion in a mixture of acetylacetone-ethanol on the physic... more The influence of BaTiO3 nanopowder dispersion in a mixture of acetylacetone-ethanol on the physicochemical and surface properties of electrophoretic coatings have been investigated. From the above data it can be seen that increasing the content of acetylacetone in a suspension increases the intensity of electrophoretic deposition of ferroelectrics. In addition, this effect is manifested of mixture ethanol-acetylacetone (1:1). With a higher content of acetylacetone, the weight of coatings is slightly reduced. Moreover, the investigation of the surface structure BaTiO3 electrophoretic coatings showed that the profiles of their surfaces Ra and Rz increased with electric field to 100 V/cm. An increase in the duration of dispersion of a powder in a mixture of acetylacetone-ethanol is accompanied by a decrease in the roughness of the coating surface, especially at low values of the tension of electric field. Thus, homogeneous electrophoretic coatings can be formed by deliberately changing the conditions of formation and deposition of suspensions BaTiO3 nanopowders. It is first stated the sedimentation for 2 % suspensions of BaTiO3 nanodispersed powder, depending on the time of milling dispersion. Together with the laser granulometry it was stated that exactly 48 hours of dispersion produce homogeneous and stable suspensions. The precipitation of a suspension in the region of 10-20 V/cm, BaTiO3 coatings can be formed by roughness of Ra 90-150 nm and Rq 100-150 nm, respectively. The results of the research will be used in the development of technology for the formation of multilayer capacitors.

Process of photoelectrocatalytic aminoazodye methyl orange (MO) degradation was studied in a neut... more Process of photoelectrocatalytic aminoazodye methyl orange (MO) degradation was studied in a neutral salt electrolyte under UV irradiation with the titanium dioxide photoelectrocatalyst of nanodispersed morphology and anatase structure synthesized by developed by authors technology from metatitanic acid TiO(OH)2 suspension. The activity was also compared with standard samples (P25 with anatase / rutile phase ratio of 80 : 20, pure rutile). The phase composition, unit cell parameters, and dispersion of the samples were determined. The results of thermogravimetric measurements, characteristics of porosity were also analyzed. The presence of Ti3+ defects for the synthesized sample could be the reason of band gap decrease in this semiconductor to 2.75 eV and growth of MOs anode oxidation currents under UV irradiation at high scan rates (above 50 mV / s) and potentials below 500 mV (CSE) comparing with standard samples. The photoelectrocatalytic activity of samples is defined by nanodisp...

Condensed Matter

Nanosized composites CeO2–Ag, La2O3–Ag, and TiO2–Ag are a class of nanomaterials suitable for pho... more Nanosized composites CeO2–Ag, La2O3–Ag, and TiO2–Ag are a class of nanomaterials suitable for photocatalysis, optical devices, and photoelectrochemical elements. Further, nanocomposites with several wt.% of silver can be used as creating materials for pathogenic virus inactivation with pandemic-neutralizing potential. Thus, CeO2–Ag, La2O3–Ag, and TiO2–Ag nanocomposites are prospective materials due to their optical and biological activity. In the present work, CeO2–Ag, La2O3–Ag, and TiO2–Ag nanocomposites were synthesized by the co-precipitation method. The morphological and optical properties and the structure of the prepared nanocomposites were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) with EDX, and nitrogen adsorption-desorption based on BET, Raman spectroscopy, and photoluminescence (PL). Both oxide matrixes corresponded to the cubic crystal lattice with the inclusion of argentum into the crystal lattice of oxides at relative low c(Ag) and reduct...

Journal of Nano- and Electronic Physics, 2021

Journal of Chemistry and Technologies, 2019

The influence of BaTiO3 nanopowder dispersion in a mixture of acetylacetone-ethanol on the physic... more The influence of BaTiO3 nanopowder dispersion in a mixture of acetylacetone-ethanol on the physicochemical and surface properties of electrophoretic coatings have been investigated. From the above data it can be seen that increasing the content of acetylacetone in a suspension increases the intensity of electrophoretic deposition of ferroelectrics. In addition, this effect is manifested of mixture ethanol-acetylacetone (1:1). With a higher content of acetylacetone, the weight of coatings is slightly reduced. Moreover, the investigation of the surface structure BaTiO3 electrophoretic coatings showed that the profiles of their surfaces Ra and Rz increased with electric field to 100 V/cm. An increase in the duration of dispersion of a powder in a mixture of acetylacetone-ethanol is accompanied by a decrease in the roughness of the coating surface, especially at low values of the tension of electric field. Thus, homogeneous electrophoretic coatings can be formed by deliberately changing the conditions of formation and deposition of suspensions BaTiO3 nanopowders. It is first stated the sedimentation for 2 % suspensions of BaTiO3 nanodispersed powder, depending on the time of milling dispersion. Together with the laser granulometry it was stated that exactly 48 hours of dispersion produce homogeneous and stable suspensions. The precipitation of a suspension in the region of 10-20 V/cm, BaTiO3 coatings can be formed by roughness of Ra 90-150 nm and Rq 100-150 nm, respectively. The results of the research will be used in the development of technology for the formation of multilayer capacitors.

2021 IEEE 11th International Conference Nanomaterials: Applications & Properties (NAP), 2021

CeO2 & Ag0 and TiO2 & Ag0 nanocomposite particles formed as a result of co-precipitation ... more CeO2 & Ag0 and TiO2 & Ag0 nanocomposite particles formed as a result of co-precipitation were analyzed using XRD, CEM, and EDS methods. Heating the precursor in the temperature range from 400 to 600°C allows to obtain on their surface a homogeneous phase of cerium and titanium dioxide (anatase) modified with silver clusters. Heat treatment causes particle size reduction. The general mechanism of the phase formation process is closely related to the direct red-ox reaction between trivalent cerium or titanium and silver cations without reducing agents adding.

Journal of Nano- and Electronic Physics, 2021

Ag/TiO2 nanoparticles (NPs) were prepared by a simple chemical deposition method using silver nit... more Ag/TiO2 nanoparticles (NPs) were prepared by a simple chemical deposition method using silver nitrate and suspension of TiO(OH)2. Silver NPs were deposited on the surface and inside of TiO2 NPs depended on the Ag concentration. The Ag/TiO2 composites were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy. The cell viability was assessed using an MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay after NPs exposure, since only viable cells have functional mitochondrial dehydrogenase enzymes that can reduce MTT to formazan. The shift of the Eg mode from 143 to 150 cm-1 and FWHM from 12 to 19 cm-1 was stated due to a decrease in TiO2 crystallites. Optical activity increased after loading with Ag because metal particles offered electron traps to reduce recombination of holes and electrons, especially Ag loading of 8 wt. %. A Schottky barrier is formed in the Ag-TiO2 contact region, which improves charge separation and thus slows down the recombination of photogenerated electrons and photogenerated holes. The obtained results indicate a lower toxicity of NPs in a glycerin + water suspension, regardless of the introduction of silver molecules in an amount of 4 or 8 wt. %, their CC50 values were 50 and 3.9-58.5 g/ml for MDBK and MDCK cells, respectively. The obtained Ag/TiO2 NPs due to their optical activity will be examined as an antifungal material for the inhibition of bacteria and viruses in water.

2021 IEEE 11th International Conference “Nanomaterials: Applications & Properties” (NAP-2021) Odesa, Ukraine, Sept. 5-11, 2021 , 2021

CeO2 & Ag 0 and TiO2 & Ag 0 nanocomposite particles formed as a result of co-precipitation were a... more CeO2 & Ag 0 and TiO2 & Ag 0 nanocomposite particles formed as a result of co-precipitation were analyzed using XRD, CEM, and EDS methods. Heating the precursor in the temperature range from 400 to 600 °C allows to obtain on their surface a homogeneous phase of cerium and titanium dioxide (anatase) modified with silver clusters. Heat treatment causes particle size reduction. The general mechanism of the phase formation process is closely related to the direct red-ox reaction between trivalent cerium or titanium and silver cations without reducing agents adding.

Process of photoelectrocatalytic aminoazodye methyl orange (MO) degradation was studied in a neut... more Process of photoelectrocatalytic aminoazodye methyl orange (MO) degradation was studied in a neutral salt electrolyte under UV irradiation with the titanium dioxide photoelectrocatalyst of nanodispersed morphology and anatase structure synthesized by developed by authors technology from metatitanic acid TiO(OH)2 suspension. The activity was also compared with standard samples (P25 with anatase / rutile phase ratio of 80 : 20, pure rutile). The phase composition, unit cell parameters, and dispersion of the samples were determined. The results of thermogravimetric measurements, characteristics of porosity were also analyzed. The presence of Ti 3+ defects for the synthesized sample could be the reason of band gap decrease in this semiconductor to 2.75 eV and growth of MOs anode oxidation currents under UV irradiation at high scan rates (above 50 mV / s) and potentials below 500 mV (CSE) comparing with standard samples. The photoelectrocatalytic activity of samples is defined by nanodispersity, crystallite morphology, pore size distribution, varies symbatically with the concentration of Ti 3+ , surface hydroxide groups.

Composite TiO 2-based photocatalysts are studied. They increase the efficiency of water and air p... more Composite TiO 2-based photocatalysts are studied. They increase the efficiency of water and air purification from toxic organic impurities and allow the synthesis of hydrogen by water photolysis and CO 2 reduction to methane and its homologues. These processes are of huge scientific and practical interest because they are aimed at solving global energy conservation problems. The latest achievements in the production of composites with various polymer matrices and nanosized oxide particles are demonstrated. The properties of these materials and their potential applications are described. An alternative option is considered, such as modification of nanosized particles by substances of different natures, to improve the photocatalytic properties of TiO 2 and shift the absorption spectrum into the visible light region. The positive and negative effects of impurities introduced into the TiO 2 structure on the photocatalytic activity are addressed. The study of various additives influencing the optical and photocatalytic properties of TiO 2 is among the priority areas in modern photochemistry.

Books by Maksym Zahornyi

Today, innovative technologies using organic-inorganic composite materials are driving rapid prog... more Today, innovative technologies using organic-inorganic composite
materials are driving rapid progress in the development of novel water
purification technologies. The unique surface, optical, and catalytic properties of nanomaterials based on oxide nanoparticles with varied natures has found widespread application in wastewater treatment.
Nanosized titanium dioxide and its composites are the most
promising photocatalytically active materials and this book gives an
overview of their application in photocatalysis and photoelectrocatalysis. In light of the continuing COVID-19 global emergency, this monograph also
discusses the antimicrobial and antiviral activity of TiO2 nanoparticles. A
number of semiconducting and bioactive catalysts based on conjugated
polymers and TiO2-MnO2, which have a redox function in water
purification, are introduced.
The aim of this monograph is to analyse the state-of-the-art in this
rapidly developing research area. As such, the authors’ original research
data are presented and composites based on polyaniline, polypyrrole, and
nanosized TiO2 nanoparticles are investigated.
Keywords: nanomaterials, TiO2, photocatalyst, photoelectrocatalysis,
conducting polymer, PANI, PPy.

Journal of chemistry and technologies, Oct 11, 2019

The influence of BaTiO3 nanopowder dispersion in a mixture of acetylacetone-ethanol on the physic... more The influence of BaTiO3 nanopowder dispersion in a mixture of acetylacetone-ethanol on the physicochemical and surface properties of electrophoretic coatings have been investigated. From the above data it can be seen that increasing the content of acetylacetone in a suspension increases the intensity of electrophoretic deposition of ferroelectrics. In addition, this effect is manifested of mixture ethanol-acetylacetone (1:1). With a higher content of acetylacetone, the weight of coatings is slightly reduced. Moreover, the investigation of the surface structure BaTiO3 electrophoretic coatings showed that the profiles of their surfaces Ra and Rz increased with electric field to 100 V/cm. An increase in the duration of dispersion of a powder in a mixture of acetylacetone-ethanol is accompanied by a decrease in the roughness of the coating surface, especially at low values of the tension of electric field. Thus, homogeneous electrophoretic coatings can be formed by deliberately changing the conditions of formation and deposition of suspensions BaTiO3 nanopowders. It is first stated the sedimentation for 2 % suspensions of BaTiO3 nanodispersed powder, depending on the time of milling dispersion. Together with the laser granulometry it was stated that exactly 48 hours of dispersion produce homogeneous and stable suspensions. The precipitation of a suspension in the region of 10-20 V/cm, BaTiO3 coatings can be formed by roughness of Ra 90-150 nm and Rq 100-150 nm, respectively. The results of the research will be used in the development of technology for the formation of multilayer capacitors.

Process of photoelectrocatalytic aminoazodye methyl orange (MO) degradation was studied in a neut... more Process of photoelectrocatalytic aminoazodye methyl orange (MO) degradation was studied in a neutral salt electrolyte under UV irradiation with the titanium dioxide photoelectrocatalyst of nanodispersed morphology and anatase structure synthesized by developed by authors technology from metatitanic acid TiO(OH)2 suspension. The activity was also compared with standard samples (P25 with anatase / rutile phase ratio of 80 : 20, pure rutile). The phase composition, unit cell parameters, and dispersion of the samples were determined. The results of thermogravimetric measurements, characteristics of porosity were also analyzed. The presence of Ti3+ defects for the synthesized sample could be the reason of band gap decrease in this semiconductor to 2.75 eV and growth of MOs anode oxidation currents under UV irradiation at high scan rates (above 50 mV / s) and potentials below 500 mV (CSE) comparing with standard samples. The photoelectrocatalytic activity of samples is defined by nanodisp...

Condensed Matter

Nanosized composites CeO2–Ag, La2O3–Ag, and TiO2–Ag are a class of nanomaterials suitable for pho... more Nanosized composites CeO2–Ag, La2O3–Ag, and TiO2–Ag are a class of nanomaterials suitable for photocatalysis, optical devices, and photoelectrochemical elements. Further, nanocomposites with several wt.% of silver can be used as creating materials for pathogenic virus inactivation with pandemic-neutralizing potential. Thus, CeO2–Ag, La2O3–Ag, and TiO2–Ag nanocomposites are prospective materials due to their optical and biological activity. In the present work, CeO2–Ag, La2O3–Ag, and TiO2–Ag nanocomposites were synthesized by the co-precipitation method. The morphological and optical properties and the structure of the prepared nanocomposites were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) with EDX, and nitrogen adsorption-desorption based on BET, Raman spectroscopy, and photoluminescence (PL). Both oxide matrixes corresponded to the cubic crystal lattice with the inclusion of argentum into the crystal lattice of oxides at relative low c(Ag) and reduct...

Journal of Nano- and Electronic Physics, 2021

Journal of Chemistry and Technologies, 2019

The influence of BaTiO3 nanopowder dispersion in a mixture of acetylacetone-ethanol on the physic... more The influence of BaTiO3 nanopowder dispersion in a mixture of acetylacetone-ethanol on the physicochemical and surface properties of electrophoretic coatings have been investigated. From the above data it can be seen that increasing the content of acetylacetone in a suspension increases the intensity of electrophoretic deposition of ferroelectrics. In addition, this effect is manifested of mixture ethanol-acetylacetone (1:1). With a higher content of acetylacetone, the weight of coatings is slightly reduced. Moreover, the investigation of the surface structure BaTiO3 electrophoretic coatings showed that the profiles of their surfaces Ra and Rz increased with electric field to 100 V/cm. An increase in the duration of dispersion of a powder in a mixture of acetylacetone-ethanol is accompanied by a decrease in the roughness of the coating surface, especially at low values of the tension of electric field. Thus, homogeneous electrophoretic coatings can be formed by deliberately changing the conditions of formation and deposition of suspensions BaTiO3 nanopowders. It is first stated the sedimentation for 2 % suspensions of BaTiO3 nanodispersed powder, depending on the time of milling dispersion. Together with the laser granulometry it was stated that exactly 48 hours of dispersion produce homogeneous and stable suspensions. The precipitation of a suspension in the region of 10-20 V/cm, BaTiO3 coatings can be formed by roughness of Ra 90-150 nm and Rq 100-150 nm, respectively. The results of the research will be used in the development of technology for the formation of multilayer capacitors.

2021 IEEE 11th International Conference Nanomaterials: Applications & Properties (NAP), 2021

CeO2 & Ag0 and TiO2 & Ag0 nanocomposite particles formed as a result of co-precipitation ... more CeO2 & Ag0 and TiO2 & Ag0 nanocomposite particles formed as a result of co-precipitation were analyzed using XRD, CEM, and EDS methods. Heating the precursor in the temperature range from 400 to 600°C allows to obtain on their surface a homogeneous phase of cerium and titanium dioxide (anatase) modified with silver clusters. Heat treatment causes particle size reduction. The general mechanism of the phase formation process is closely related to the direct red-ox reaction between trivalent cerium or titanium and silver cations without reducing agents adding.

Journal of Nano- and Electronic Physics, 2021

Ag/TiO2 nanoparticles (NPs) were prepared by a simple chemical deposition method using silver nit... more Ag/TiO2 nanoparticles (NPs) were prepared by a simple chemical deposition method using silver nitrate and suspension of TiO(OH)2. Silver NPs were deposited on the surface and inside of TiO2 NPs depended on the Ag concentration. The Ag/TiO2 composites were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy. The cell viability was assessed using an MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay after NPs exposure, since only viable cells have functional mitochondrial dehydrogenase enzymes that can reduce MTT to formazan. The shift of the Eg mode from 143 to 150 cm-1 and FWHM from 12 to 19 cm-1 was stated due to a decrease in TiO2 crystallites. Optical activity increased after loading with Ag because metal particles offered electron traps to reduce recombination of holes and electrons, especially Ag loading of 8 wt. %. A Schottky barrier is formed in the Ag-TiO2 contact region, which improves charge separation and thus slows down the recombination of photogenerated electrons and photogenerated holes. The obtained results indicate a lower toxicity of NPs in a glycerin + water suspension, regardless of the introduction of silver molecules in an amount of 4 or 8 wt. %, their CC50 values were 50 and 3.9-58.5 g/ml for MDBK and MDCK cells, respectively. The obtained Ag/TiO2 NPs due to their optical activity will be examined as an antifungal material for the inhibition of bacteria and viruses in water.

2021 IEEE 11th International Conference “Nanomaterials: Applications & Properties” (NAP-2021) Odesa, Ukraine, Sept. 5-11, 2021 , 2021

CeO2 & Ag 0 and TiO2 & Ag 0 nanocomposite particles formed as a result of co-precipitation were a... more CeO2 & Ag 0 and TiO2 & Ag 0 nanocomposite particles formed as a result of co-precipitation were analyzed using XRD, CEM, and EDS methods. Heating the precursor in the temperature range from 400 to 600 °C allows to obtain on their surface a homogeneous phase of cerium and titanium dioxide (anatase) modified with silver clusters. Heat treatment causes particle size reduction. The general mechanism of the phase formation process is closely related to the direct red-ox reaction between trivalent cerium or titanium and silver cations without reducing agents adding.

Process of photoelectrocatalytic aminoazodye methyl orange (MO) degradation was studied in a neut... more Process of photoelectrocatalytic aminoazodye methyl orange (MO) degradation was studied in a neutral salt electrolyte under UV irradiation with the titanium dioxide photoelectrocatalyst of nanodispersed morphology and anatase structure synthesized by developed by authors technology from metatitanic acid TiO(OH)2 suspension. The activity was also compared with standard samples (P25 with anatase / rutile phase ratio of 80 : 20, pure rutile). The phase composition, unit cell parameters, and dispersion of the samples were determined. The results of thermogravimetric measurements, characteristics of porosity were also analyzed. The presence of Ti 3+ defects for the synthesized sample could be the reason of band gap decrease in this semiconductor to 2.75 eV and growth of MOs anode oxidation currents under UV irradiation at high scan rates (above 50 mV / s) and potentials below 500 mV (CSE) comparing with standard samples. The photoelectrocatalytic activity of samples is defined by nanodispersity, crystallite morphology, pore size distribution, varies symbatically with the concentration of Ti 3+ , surface hydroxide groups.

Composite TiO 2-based photocatalysts are studied. They increase the efficiency of water and air p... more Composite TiO 2-based photocatalysts are studied. They increase the efficiency of water and air purification from toxic organic impurities and allow the synthesis of hydrogen by water photolysis and CO 2 reduction to methane and its homologues. These processes are of huge scientific and practical interest because they are aimed at solving global energy conservation problems. The latest achievements in the production of composites with various polymer matrices and nanosized oxide particles are demonstrated. The properties of these materials and their potential applications are described. An alternative option is considered, such as modification of nanosized particles by substances of different natures, to improve the photocatalytic properties of TiO 2 and shift the absorption spectrum into the visible light region. The positive and negative effects of impurities introduced into the TiO 2 structure on the photocatalytic activity are addressed. The study of various additives influencing the optical and photocatalytic properties of TiO 2 is among the priority areas in modern photochemistry.

Today, innovative technologies using organic-inorganic composite materials are driving rapid prog... more Today, innovative technologies using organic-inorganic composite
materials are driving rapid progress in the development of novel water
purification technologies. The unique surface, optical, and catalytic properties of nanomaterials based on oxide nanoparticles with varied natures has found widespread application in wastewater treatment.
Nanosized titanium dioxide and its composites are the most
promising photocatalytically active materials and this book gives an
overview of their application in photocatalysis and photoelectrocatalysis. In light of the continuing COVID-19 global emergency, this monograph also
discusses the antimicrobial and antiviral activity of TiO2 nanoparticles. A
number of semiconducting and bioactive catalysts based on conjugated
polymers and TiO2-MnO2, which have a redox function in water
purification, are introduced.
The aim of this monograph is to analyse the state-of-the-art in this
rapidly developing research area. As such, the authors’ original research
data are presented and composites based on polyaniline, polypyrrole, and
nanosized TiO2 nanoparticles are investigated.
Keywords: nanomaterials, TiO2, photocatalyst, photoelectrocatalysis,
conducting polymer, PANI, PPy.