Technical graphene (reduced graphene oxide) and its natural analog (shungite)

Sheka, E. F.; Голубев, Е. А.

doi:10.1134/s1063784216070239

Cited by 26 publications

(32 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The list of synthetic ACs continues to expand since more and more techniques appear to produce this highly requested material. Evidently, it should be complemented with 'technical graphenes' that cover a large class of high-tech new materials produced in the course of reduction of graphene oxide [3]. The list of natural ACs has been unchanged for a long time until scrupulous studies of graphene-like shungite carbon [4][5][6] and anthraxolite [7] have provided a new pulse which convincingly pointed that these two mineral products should be included as well.…”

Section: Introductionmentioning

confidence: 99%

sp amorphous carbons in view of multianalytical consideration: Normal, expeсted and new

Golubev

Rozhkova

Кабачков

et al. 2019

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

The suggested approach "Selected set of samples + selected set of analytical tools" occurred quite efficient when applying to sp 2 amorphous carbons, thus providing a transformation of 'amorphous' representation of the issue, based on particulars, into a 'crystalline' one based on a limited set of fixed commonalities. The slogan first part implies a set of different-origin solid samples. The second part concerns analytical tools, the most suitable to achieve the goal. The parts combining means the application of each tool to the whole set of samples. In the current study, two natural sp 2 amorphous carbons, namely, shungite carbon and antraxolite, as well as two engineered products -carbon blacks CB632 and CB624, all of the four bodies belonging to the elitist highest-carbon-content sp 2 species, were subjected to analytical study by using modern structural and compositional analytical techniques. The approach has allowed disclosing the following steady points that are common to the whole class of this carbon allotrope and that may lay the foundation of consolidate, more 'crystalline' representation of what are sp 2 amorphous carbons:1. sp 2 Amorphous carbons are products of particular chemical reactions related to their basic structural units. Further macroscopic agglomeration of the latter plays a subsidiary role. 2. The units represent framed graphene molecules of 1-2 nm and 1-x*10 (x=1-3) nm in size in the case of natural and engineered products, respectively.3. Framing of graphene molecules, predominantly incomplete with respect to the number of vacant places, concerns only edge atoms and is implemented by the related chemical additives, such as hydrogen, oxygen, nitrogen, sulfur and halogens which are attached to the carbon core via chemical bonding. 4. The molecules small size provides a countable number of newly formed chemical bonds.INS and XPS allow attributing the bonds to chemical compositions restricted by number while QCh ensures reliable support. 5. Temperature and pressure as well as physical state and chemical content of surrounding media are the main factors governing geochemistry and technical chemistry of carbon products. 6. Graphene molecules, laying the foundation of sp 2 amorphous carbons, are strongly radicalized due to which the latter acquire a new facet in the space of their properties, being the largest repository of stable radicals.

show abstract

Section: Introductionmentioning

confidence: 99%

sp amorphous carbons in view of multianalytical consideration: Normal, expeсted and new

Golubev

Rozhkova

Кабачков

et al. 2019

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

show abstract

“…Evidently, the effect depends on the chemical composition of the GO basal planes, the number of GO layers in stacks, the shape of the relevant GO sheets, the lateral size of the sheets, and other factors. Due to high variability of GO materials with regards to these parameters [7,[26][27][28][29][30], one should expect widely variable INS spectra for samples, which was observed in the two studied cases.…”

Section: Retained Water Spectramentioning

confidence: 99%

“…The fixation of the interlayer distance in the rGO stacks in all the studied cases from 3.4 -3.6Å proves that the relevant hydrogen atoms occupy the circumference (ccf ) area of the rGO sheets, and as a result, the latter should be attributed to framed ccf oxyhydrides of graphene (FOHG). Similar to GOs, FOHGs are highly variable by chemical composition, size, and shape [2,7,[26][27][28][29][30] and unsurprisingly, their properties also widely change. The latter should be naturally attributed to the IINS spectra as well.…”

Section: Rgo Spectramentioning

confidence: 99%

See 1 more Smart Citation

Parent and reduced graphene oxide of different origin in light of neutron scattering

Sheka¹,

Natkaniec²,

Rozhkova³

et al. 2016

Nanosystems: Phys. Chem. Math.

View full text Add to dashboard Cite

The current paper presents results from an extended neutron scattering study of a three-part set of parent and reduced graphene oxides (GO and rGO, respectively) of different origins. The first part concerns the rGO of natural origin represented by shungite carbon, the second and third parts are related to synthetic GO/rGO pairs with the latter produced during either chemical treatment or via thermal exfoliation of the parent GO, respectively. The study involved both the neutron diffraction and inelastic neutron scattering. The one-phonon amplitude-weighted density of vibrational states G(ω) represents the inelastic incoherent neutron scattering spectra of the products. Common characteristics and individual distinctions of the studied species are discussed.

show abstract

“…Confined names AC-Ccats, CNT-Ccats, GO-Ccats, and Gr-Ccats will be used bellow to facilitate the description of AC-, CNT-, GO-, and Gr-based carbocatalists, respectively. In the latter case, the term combines mainly rGO, better known as "technical graphene" [22] as well as other graphene fragments.…”

Section: Introduction: Modern Carbocatalysis and Its Problemsmentioning

confidence: 99%

Graphene Oxyhydride Catalysts in View of Spin Radical Chemistry

Sheka

2020

Materials

View full text Add to dashboard Cite

The article discusses carbocatalysis provided with amorphous carbons. The discussion is conducted from the standpoint of the spin chemistry of graphene molecules, in the framework of which the amorphous carbocatalysts are a conglomerate of graphene-oxynitrothiohydride stable radicals presenting the basic structural units (BSUs) of the species. The chemical activity of the BSUs atoms is reliably determined computationally, which allows mapping the distribution of active sites in these molecular catalysts. The presented maps reliably evidence the BSUs radicalization provided with carbon atoms only, the non-terminated edge part of which presents a set of active cites. Spin mapping of carbocatalysts active cites is suggested as the first step towards the spin carbocatalysis of the species.

show abstract

Technical graphene (reduced graphene oxide) and its natural analog (shungite)

Cited by 26 publications

References 12 publications

sp amorphous carbons in view of multianalytical consideration: Normal, expeсted and new

sp amorphous carbons in view of multianalytical consideration: Normal, expeсted and new

Parent and reduced graphene oxide of different origin in light of neutron scattering

Graphene Oxyhydride Catalysts in View of Spin Radical Chemistry

Contact Info

Product

Resources

About