Graphene workshop 2022

Workshop: Atmospheric Pressure Plasma Synthesis of Graphene and Its Derivates and Their Applications offered several interesting oral lectures for attendees on the topic of graphene research from fundamentals, preparation, characterization to applications. Lectures were prepared by our colleagues in cooperation with researchers from Spain.

• Prof. M. Dolores Calzada Canalejo - Laboratory of innovation in plasmas (University of Córdoba): from plasma basics and fundamentals to its applications - At the laboratory of Innovation in Plasmas (University of Córdoba) two complementary research lines are being followed: (i) pursue leading edge fundamental studies in the field of plasma sources and plasma diagnosis and (ii) capitalize on this plasma expertise to perform extremely original and innovative research on plasma-based applications such as hydrogen generation, synthesis of carbon nanostructured material (nanotubes and graphene), treatment of material surfaces, food preservation, analysis of chemical samples, among others. In this talk, a summary of those research lines is being presented.

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• Assoc. Prof. Rocio Rincón Liévana - Microwave plasmas at atmospheric pressure for hydrogen production and 2D materials assembly - The aim of this talk is to review some selected aspects of low-temperature plasmas for hydrogen production and graphene formation. The reforming technologies based on non-thermal plasma treatment of hydrocarbons and alcohols show promising prospects to produce hydrogen as a future green energy vector. Moreover, plasma technology is suggested as a invaluable tool for the synthesis and engineering of new nanomaterials and, particularly, 2D materials. In this talk, the applicability of plasma technology will be critically assessed and compared with other techniques which might be of help for future research.

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• dr. Ondřej Jašek - Synthesis and functional properties of few-layer graphene prepared by decomposition of organic precursors using dual-channel microwave plasma torch - Microwave plasma decomposition of organic precursors, hydrocarbons and alcohols, forms a high-temperature environment, where the process of catalyst-free dehydrogenation and consequent formation C atoms and C2 molecules leads to the nucleation and growth of high-quality few-layer graphene nanosheets. In this work we show how the spatial and temporal distribution of heat field formed by microwave plasma environment influences the reaction pathway of atomic and molecular species and leads to a high yield synthesis of graphene and enables synthesis of structure with controlled functional properties. Comparison between electrical, thermal, and mechanical properties of gas-phase synthesized graphene and liquid exfoliated graphene will be presented.

• dr. Andrés M. Raya Bejarano - Graphene characterization: analysis techniques and challenges - Plasma technology has proved its efficacy for graphene synthesis. However, the characterization of the material is still challenging. This talk aims to review the most important graphene characterization techniques focusing on the use of electron microscopy for the analysis of graphene powder obtained together with copper nanoparticles

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• prof. Vít Kudrle - Enhanced diagnostics of filamentary microwave plasma - Microwave jets, similarly to other discharges at atmospheric pressure, often exhibit a radially constricted plasma, i.e. filament(s). Certain details, especially the presence of surface wave along the filament, nature of the "shells'' surrounding the filament and mutual influence of multiple filaments, are still not fully understood. Better measurements and better theory are direly needed. Optical plasma diagnostics in both axial and radial direction provided important information about plasma density and temperature. Microwave diagnostics of the plasma torch/jet has some inherent problems, as the classical criteria (planar waves, infinite plasma slab, sub-critical plasma, etc.) are not satisfied. Nevertheless, we used numerical modelling to precompute what should be observed for various combinations of plasma geometry and density profiles and then compared these predicted values (resonance frequency shift or phase shift) with the actual experimental ones. By such "backward'' fitting process we have got the sought parameters - plasma density and its profile.

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• Francisco Javier Morales-Calero - Spatial structure of the atmospheric pressure plasma generated by the TIAGO torch: towards the optimization of graphene synthesis - The synthesis of graphene by means of TIAGO torch microwave plasma needs to be optimized, for that reason, fundamental studies of this kind of plasma are required. In this talk, new insights concerning the characterization of TIAGO torch-based plasma as a surface wave discharge are presented.

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• dr. Richard Krumpolec - Simple and fast atmospheric plasma reduction and exfoliation of graphene oxide - In the talk we will show how atmospheric pressure diffuse & filamentary plasma generated by dielectric barrier discharge can trigger extremely fast reduction and exfoliation of graphene oxide into the reduced graphene oxide (rGO) even in standard technical gases like nitrogen and the air. This novel, simple and scalable reduction-exfoliation method thus enables low-cost industrial-scale production of conductive rGO sheets and rGO-based composites for various modern applications that will be presented.