Two-Dimensional Geometry Control of Graphene Nanoflakes Produced by Thermal Plasma for Catalyst Applications

Meunier, Jean‐Luc; Mendoza-Gonzalez, Norma Y.; Pristavita, Ramona; Binny, Dustin; Berk, Dimitrios

doi:10.1007/s11090-014-9524-6

Cited by 53 publications

(30 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It can be assumed that hydrogen from C3H remains in the C-C structure and influences the shape of In Figures 19 and 20, evolution of the molar composition of the argon plasma is presented in detail, in two ranges of concentration. Results of calculations are in agreement with the references [40][41][42]. Evidently the critical temperature of the beginning of condensation in this case is 3300 K. The formation of condensed carbon goes on at the expense of C, C 2 , C 3 , C 5 , C 2 H, C 2 H 2 , C 4 H 2 , and C 3 H. It can be assumed that hydrogen from C 3 H remains in the C-C structure and influences the shape of the future graphene structure.…”

Section: Resultssupporting

confidence: 88%

Distinctive Features of Graphene Synthesized in a Plasma Jet Created by a DC Plasma Torch

Shavelkina¹,

Иванов²,

Bocharov³

et al. 2020

Materials

View full text Add to dashboard Cite

Synthesis of graphene materials in a plasma stream from an up to 40 kW direct current (DC) plasma torch is investigated. These materials are created by means of the conversion of hydrocarbons under the pressure 350–710 Torr without using catalysts, without additional processes of inter-substrate transfer and the elimination of impurities. Helium and argon are used as plasma-forming gas, propane, butane, methane, and acetylene are used as carbon precursors. Electron microscopy and Raman imaging show that synthesis products represent an assembly of flakes varying in the thickness and the level of deformity. An occurrence of hydrogen in the graphene flakes is discovered by X-ray photoelectron spectroscopy, thermal analysis, and express-gravimetry. Its quantity depends on the type of carrier gas. Quasi-one-dimensional approach under the local thermodynamic equilibrium was used to investigate the evolution of the composition of helium and argon plasma jets with hydrocarbon addition. Hydrogen atoms appear in the hydrogen-rich argon jet under higher temperature. This shows that solid particles live longer in the hydrogen-rich environment compared with the helium case providing some enlargement of graphene with less hydrogen in its structure. In conclusion, graphene in flakes appears because of the volumetric synthesis in the hydrogen environment. The most promising directions of the practical use of graphеne flakes are apparently related to structural ceramics.

show abstract

Section: Resultssupporting

confidence: 88%

Distinctive Features of Graphene Synthesized in a Plasma Jet Created by a DC Plasma Torch

Shavelkina¹,

Иванов²,

Bocharov³

et al. 2020

Materials

View full text Add to dashboard Cite

show abstract

“…The thermal efficiency of the plasma generator ranges from 40%-60%). As suggested by Pristavita et al [23,27] and Wang et al [31], the essential gas temperature for graphene flakes synthesis is more than 3000 K. Therefore, the average gas temperature in this experiment is controlled to be 3500 K, and the temperature error is roughly ± 300 K. The input power is controlled by changing the arc current. During the course of the experiment, the argon is first injected into the plasma generator, and the arc is ignited under a pure Ar atmosphere.…”

Section: Experimental Parametersmentioning

confidence: 85%

“…In a recent study, Whitesides et al [77] investigated the growth of graphene-edges using kinetic Monte Carlo simulations and indicated that a high-energy environment can suppress the formation of a five-member-ring, which corresponds to the curved or closed structures, and, consequently, lead to the formation of planar graphene flakes. Recent experimental studies also confirm that a high-energy environment can facilitate the formation of planar graphene flakes rather than spherical particles [11,23,27,31]. Thus, variations in gas enthalpy may represent an important factor behind changes in product morphology.…”

Section: Discussionmentioning

confidence: 95%

“…Their research revealed that factors influencing graphene flakes synthesis include the precursor type, reactor design, flow rate of buffer gas, etc. Pristavita et al [23][24][25][26][27][28] and Cheng et al [29] developed a radio-frequency plasma system for graphene flakes synthesis via methane decomposition. Their study indicated that a high reaction temperature and addition of H 2 may promote the transformation of products from spherical particles to graphene flakes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Buffer Gases on Graphene Flakes Synthesis in Thermal Plasma Process at Atmospheric Pressure

et al. 2020

View full text Add to dashboard Cite

A thermal plasma process at atmospheric pressure is an attractive method for continuous synthesis of graphene flakes. In this paper, a magnetically rotating arc plasma system is employed to investigate the effects of buffer gases on graphene flakes synthesis in a thermal plasma process. Carbon nanomaterials are prepared in Ar, He, Ar-H2, and Ar-N2 via propane decomposition, and the product characterization is performed by transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and the Brunauer–Emmett–Teller (BET) method. Results show that spherical particles, semi-graphitic particles, and graphene flakes coexist in products under an Ar atmosphere. Under an He atmosphere, all products are graphene flakes. Graphene flakes with fewer layers, higher crystallinity, and a larger BET surface area are prepared in Ar-H2 and Ar-N2. Preliminary analysis reveals that a high-energy environment and abundant H atoms can suppress the formation of curved or closed structures, which leads to the production of graphene flakes with high crystallinity. Furthermore, nitrogen-doped graphene flakes with 1–4 layers are successfully synthesized with the addition of N2, which indicates the thermal plasma process also has great potential for the synthesis of nitrogen-doped graphene flakes due to its continuous manner, cheap raw materials, and adjustable nitrogen-doped content.

show abstract

“…However, it can also be utilized for the synthesis of ultrafine catalysts whose particle diameters are in the range from a few to a few tens of nanometers and specific area is highly developed [2,8]. Lately, graphene nanoflakes for catalytic applications have been produced by thermal plasma [9,10]. Also, this plasma technique is used to recover and regenerate the spent conventional catalysts [11,12].…”

Section: Introductionmentioning

confidence: 99%

Cold Plasma Produced Catalytic Materials

Tyczkowski¹

2016

Plasma Science and Technology - Progress in Physical States and Chemical Reactions

View full text Add to dashboard Cite

The cold plasma techniques are widely applied to create new materials possessing unique properties, which cannot be prepared by any other methods. "mong the many interesting substances produced with the participation of cold plasma, a special place is occupied by materials with catalytic properties. The chapter gives a brief review of various cold plasma methods used for the preparation of catalytic materials from the plasma modification of conventional catalysts via plasma-enhanced classical synthesis of catalysts to the advanced thin catalytic films fabricated by plasma sputtering processes but primarily by plasma deposition from metalorganic precursors PECVD . Recently, the catalytic films have attracted considerable attention due to the possibility of depositing them as very thin coatings on virtually all supports without any change in their geometry. Such coatings open the way for new reactor designs, so-called structured reactors, designated for various chemical processes. They can also be used as catalytic deposit on the surface of electrodes for fuel cells and photoelectrodes for water splitting processes. Recent developments in this field and further prospects for thin catalytic films are discussed, all the more so because it is one of the main areas of research in our department.Keywords: Catalysts, plasma treatment, PECVD, structured reactors, fuel cells, water splitting . IntroductionFor a long time, plasma techniques have been used in the creation of new materials possessing unique properties, which cannot be fabricated by other methods. " particularly important technique, giving plenty of possibilities, is the plasma deposition of entirely new, advanced materials in the form of solid coatings having unusual molecular structure and sophisticated nanomorphology. The plasma processes can also be used to modify conventional materials through treating them during or after "classical" synthesis, which generally leads to new © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.substances with disparate properties, often more suitable than those of the unmodified materials."mong the many interesting products fabricated by plasma techniques, materials with catalytic properties occupy a special place. There exist a lot of catalytic reactions, for example, combustion of organic volatile compounds, CO methanation, Fischer Tropsch synthesis, water photo-splitting, fuel cell electrode processes, and many others, which challenge chemists all over the world to seek better catalysts or more effective catalyst preparation methods. It seems that the plasma techniques pave the way for novel solutions in this field.In general, plasma techniques used in the preparation of catalysts can be categorized into one of two groups depending on the plasma type thermal equilibrium pl...

show abstract

Two-Dimensional Geometry Control of Graphene Nanoflakes Produced by Thermal Plasma for Catalyst Applications

Cited by 53 publications

References 17 publications

Distinctive Features of Graphene Synthesized in a Plasma Jet Created by a DC Plasma Torch

Distinctive Features of Graphene Synthesized in a Plasma Jet Created by a DC Plasma Torch

Effects of Buffer Gases on Graphene Flakes Synthesis in Thermal Plasma Process at Atmospheric Pressure

Cold Plasma Produced Catalytic Materials

Contact Info

Product

Resources

About