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Synthesis of metallic alloy particles on flat graphitic interfaces in arc discharge

Breus A., Abashin S., Serdiuk O., Sysoiev Iu.

Archives of Materials Science and Engineering

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2023

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Vol. 121, nr 2

49--59

EN

Purpose: The application of arc discharge to synthesising encapsulated (Fe-Cu-Al)@C structures is studied. The cost-effectiveness of the proposed technique may be beneficial for developing a new method for large-scale production of metal micro- and nanoparticles protected from oxidation by a carbon shell. Design/methodology/approach: A copper sample was immersed into a mixture of graphite, iron, and aluminium powder and placed into a negatively powered crucible of a setup designed to ignite arc discharge at atmospheric conditions. The proposed approach prevents the oxidation of droplets of Fe-Cu-Al alloy by covering them with a thin layer of carbon, which is also engaged as a collector of the metal particles. Findings: The application of arc discharge resulted in the generation of metal particles and various carbon nanostructures, which were confirmed by SEM images. The nanostructures were grouped into more complex flower-, ball-, tree-, and octopus-shaped structures with a large yield of metallic alloy particles ranging from a few μm (micrometers) to nanometre sizes. These findings suggest the catalytic application of the structures after the grown particles are cleared from the carbon shell to be implemented as active chemical agents. Research limitations/implications: The main limitation is the uncontrolled heat transfer from the discharge volume. Therefore, an additional screen should be installed around the volume in order to improve control over synthesis in future studies. Practical implications: This research confirms a flexible and simple method of synthesising metallic alloy particles that may be applied for catalytic applications. Originality/value: The synthesis is conducted using a well-known arc discharge technique to expand the production yield and diversity of chemically-active metal particles protected from oxidation by a shell before the intended application.

2

Anodic growth of copper oxide nanostructures in glow discharge

Breus A., Abashin S., Lukashov I., Serdiuk I.

Archives of Materials Science and Engineering

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2022

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Vol. 114, nr 1

24--33

EN

Purpose: Application of plasma glow discharge to copper oxide nanostructure growth is studied. The simplicity of the proposed technique may be beneficial for the development of new plasma reactors for large-scale production of diverse metal oxide nanostructures. Design/methodology/approach: Copper sample was placed on anode of a setup designed to ignite plasma glow discharge. The proposed approach allows eliminating the negative effects of ion bombardment, like sputtering and generation of defects on a surface of the growing nanostructures, but preserves the advantages of thermal growth. The growth process was explained in terms of thermal processes interaction occurring on a surface of the anode with the glow discharge plasma. Findings: Plasma treatment resulted in generation of reach and diverse nanostructures that was confirmed by SEM images. Nanowire-like, flower-like, anemone-like nanostructures and nanodisks composed into the nanoassemblies are observed; the nanostructures are associated with microbabbles on CuO layer. These findings allow concluding about the possible implementation of the proposed method in industry. Research limitations/implications: The main limitation is conditioned by the lack of heat supplied to the anode, and absence of independent control of the heat and ion fluxes; thus, the additional heater should be installed under the anode in order to expand the nomenclature of the nanospecies in the future studies. Practical implications: High-productivity plasma process in copper oxide nanostructures synthesis was confirmed in this research. It may be applied for field emitter and supercapacitor manufacturing. Originality/value: Oxide nanostructure synthesis is conducted by use of a simple and well-known glow discharge technique in order to expand the production yield and diversity of nanostructure obtained in the processes of thermal growth.

3

Carbon nanostructure growth: new application of magnetron discharge

Breus A., Abashin S., Serdiuk O.

Journal of Achievements in Materials and Manufacturing Engineering

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2021

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Vol. 109, nr 1

17--25

EN

Purpose: The application of a common magnetron discharge to the growth of carbon nanostructures is studied. The simplicity of the proposed technique can be beneficial for the development of new plasma reactors for large-scale production of carbon nanostructures. Design/methodology/approach: Graphite cathode was treated by carbon-containing powder accelerated by use of nozzle, and then aged in hydrogen. Superposition of glow and arc discharges was obtained, when putting the cathode under the negative biasing with respect to the walls of a vacuum chamber. The pulsed discharge was preserved through the whole time of treatment. This process was explained in terms of interaction of glow discharge plasma with a surface of the cathode made of non-melting material. Findings: The plasma treatment resulted in generation of the diverse nanostructures confirmed by SEM and TEM images. Spruce-like nanostructures and nanofibers are observed near the cathode edge where the plasma was less dense; a grass-like structure was grown in the area of “race-track”; net-like nanostructures are found among the nanofibers. These findings allow concluding about the possible implementation of the proposed method in industry. Research limitations/implications: The main limitation is conditioned by an explosive nature of nanostructure generation in arcs; thus, more elaborate design of the setup should be developed in order to collect the nanospecies in the following study. Practical implications: High-productivity plasma process of nanosynthesis was confirmed in this research. It can be used for possible manufacturing of field emitters, gas sensors, and supercapacitors. Originality/value: Synthesis of carbon nanostructures is conducted by use of a simple and well-known technique of magnetron sputtering deposition where a preliminary surface treatment is added to expand the production yield and diversity of the obtained nanostructures.