Neutron spectroscopy study of single-walled carbon nanotubes hydrogenated under high pressure

Kolesnikov, A. I.; Bashkin, I. O.; Antonov, V.E.; Colognesi, D.; Mayers, J.; Moravsky, A. P.

doi:10.1016/j.jallcom.2006.11.207

Cited by 6 publications

(6 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The occurrence of the two well-separated stages in the thermodesorption curves suggests that the quenched hydrocarbons contain hydrogen in two different forms. In the case of the quenched SWNT-H sample with x ≈ 0.61 synthesized at 3 GPa and 350°C, these two forms of the absorbed hydrogen have been identified by inelastic neutron scattering [26]. The weakly bonded hydrogen (x ≈ 0.05) leaving the sample upon heating to room temperature was shown to be the physisorbed H 2 molecules exhibiting nearly free rotational behaviour, while most H atoms (x = 0.56) were covalently bound to the carbon atoms and could only be removed by heating to T > 500°C.…”

Section: °Cmentioning

confidence: 99%

Multilayer graphane synthesized under high hydrogen pressure

Antonov

Bashkin

Bazhenov

et al. 2016

Carbon

Self Cite

View full text Add to dashboard Cite

A new hydrocarbonhydrographitewith the composition close to CH is shown to form from graphite and gaseous hydrogen at pressures above 2 GPa and temperatures from 450 to 700°C. Hydrographite is a black solid thermally stable under ambient conditions. If heated in vacuum, it decomposes into graphite and molecular hydrogen at temperatures from 500 to 650°C. Powder X-ray diffraction characterizes hydrographite as a multilayer "graphane II" phase predicted by ab initio calculations [Wen X-D et al. PNAS 2011;108:6833] and consisting of graphane sheets in the chair conformation stacked along the hexagonal c axis in the −ABAB− sequence. The crystal structure of the synthesized phase belongs to the P6 3 mc space group. The unit cell parameters are a = 2.53(1) Å and c = 9.54(1) Å and therefore exceed the corresponding parameters of graphite by 2.4(2)% and 42.0(3)%. Stretching vibrations of C-H groups on the surface of the hydrographite particles are examined by infrared spectroscopy.

show abstract

Section: °Cmentioning

confidence: 99%

Multilayer graphane synthesized under high hydrogen pressure

Antonov

Bashkin

Bazhenov

et al. 2016

Carbon

Self Cite

View full text Add to dashboard Cite

show abstract

“…24 Some hydrogenation experiments have also been performed at extremely high pressures in the GPa range. 26,27 As a result of hydrogenation, dramatic changes of the physical properties of SNWTs have been observed, for example, changes in the conductivity of metallic nanotubes. 28À30 The band gap of nanotubes with a given diameter can be tuned by varying the degree of hydrogenation and metallic tubes converted into semiconducting.…”

mentioning

confidence: 99%

“…Strong hydrogen plasma etching has been found to produce pore-like defects in carbon nanotubes and complete collapse at very high hydrogenation temperatures (above 1000 K) . Some hydrogenation experiments have also been performed at extremely high pressures in the GPa range. , …”

mentioning

confidence: 99%

Hydrogenation, Purification, and Unzipping of Carbon Nanotubes by Reaction with Molecular Hydrogen: Road to Graphane Nanoribbons

et al. 2011

View full text Add to dashboard Cite

Reaction of single-walled carbon nanotubes (SWNTs) with hydrogen gas was studied in a temperature interval of 400-550 °C and at hydrogen pressure of 50 bar. Hydrogenation of nanotubes was observed for samples treated at 400-450 °C with about 1/3 of carbon atoms forming covalent C-H bonds, whereas hydrogen treatment at higher temperatures (550 °C) occurs as an etching. Unzipping of some SWNTs into graphene nanoribbons is observed as a result of hydrogenation at 400-550 °C. Annealing in hydrogen gas at elevated conditions for prolonged periods of time (72 h) is demonstrated to result also in nanotube opening, purification of nanotubes from amorphous carbon, and removal of carbon coatings from Fe catalyst particles, which allows their complete elimination by acid treatment.

show abstract

“…The type and relative amount of these species influence the surface properties of all the carbon-based materials, are responsible for the catalytic activity of metal-free carbons as well as for the adsorption of organic reactants during the catalysis, and influence also the deposition of metal nanoparticles during the preparation of carbon-supported catalysts. [115][116][117] Albeit not diffuse as IR and Raman spectroscopies, INS has been widely applied to the investigation of carbon-based materials [118][119][120][121][122][123][124][125][126][127] and carbon-supported catalysts, [128][129][130][131][132][133][134][135] offering unprecedented details on the surface properties at the atomic level. Most of the works are related to activated carbons or coal, [118][119][120][121][122][135][136][137] while there are very few reports on INS applied to other carbonaceous materials such as graphite, graphene and carbon nanotubes, the latter motivated mainly by their potential in H 2 absorption.…”

Section: Inelastic Neutron Scattering (Ins) Technique Probes the Motimentioning

confidence: 99%

“…Most of the works are related to activated carbons or coal, [118][119][120][121][122][135][136][137] while there are very few reports on INS applied to other carbonaceous materials such as graphite, graphene and carbon nanotubes, the latter motivated mainly by their potential in H 2 absorption. [123][124][125]127 The most prolific research groups in this field are those of Albers and Parker, 111,113,118,122,[129][130][131]133,136 who published the first INS spectra of activated carbons in the late 1990s.…”

Section: Inelastic Neutron Scattering (Ins) Technique Probes the Motimentioning

confidence: 99%

CHAPTER 4. Raman, IR and INS Characterization of Functionalized Carbon Materials

Groppo¹,

Bonino²,

Cesano³

et al. 2018

Catalysis Series

View full text Add to dashboard Cite

Vibrational spectroscopies represent a powerful tool to investigate the structural properties at an atomic level. In particular, the analysis of the spectra allows to have detailed information on both structure and chemical environment of different sites. Therefore, the spectroscopic characterization can usefully assist in the comprehension of the parameters ruling the unique catalytic properties of metal-free carbon materials, as well as to implement the knowledge in the design of new C-containing systems. Keeping in mind these purposes, the present Chapter tries to provide some insights on the information obtained by using vibrational spectroscopies to characterize carbonaceous materials. Intriguing and quite recently investigated systems will be illustrated as "case histories" to show what can be learned from the analysis of the spectra collected in different experimental conditions.The results concerning activated carbons, carbon nanotubes, graphene oxide as well as carbon nitrides or fullerenes will be discussed in order to investigate the effect of the pretreatment and of the functionalization/doping on the catalytic activity in different applications. Raman spectroscopy applied to carbonsRaman spectroscopy is based on the inelastic light scattering of a laser source in the near IR -UV range.Backscattered photons come out with a lower (ν 0 −ν vibr ) or higher (ν 0 +νvibr) energy with respect to the incoming laser photons (ν 0 ). The energy difference (ν vibr ) corresponds to the vibrational mode. A Raman active vibrational mode should involve a change in the electric polarizability. This powerful technique is widely adopted in the characterization of carbon derived materials, both crystalline [e.g. HOPG (highly oriented pyrolytic graphite), nano-graphite] or amorphous (e.g. turbostratic carbon, carbon fibers etc.). Raman spectroscopy of perfect and defective graphiteThe Raman spectrum of perfect graphite (e.g. HOPG) with large crystalline domains is dominated by a sharp peak centred at 1580 cm -1 (historically indicated as G peak, first order, see Figure 1a, top), which is attributed to a E 2g mode (Figure 1c, part A). In addition, a complex envelope of bands appears in the 2800-2600 cm -1 region (second order), mostly due to combination modes. In particular, two main peaks are observed in the spectrum of perfect graphite, originally indicated as G´2 (high frequency side, sharp) and G´1

show abstract

Neutron spectroscopy study of single-walled carbon nanotubes hydrogenated under high pressure

Cited by 6 publications

References 20 publications

Multilayer graphane synthesized under high hydrogen pressure

Multilayer graphane synthesized under high hydrogen pressure

Hydrogenation, Purification, and Unzipping of Carbon Nanotubes by Reaction with Molecular Hydrogen: Road to Graphane Nanoribbons

CHAPTER 4. Raman, IR and INS Characterization of Functionalized Carbon Materials

Contact Info

Product

Resources

About