Near-edge absorption fine structure and UV photoemission spectroscopy studies of aligned single-walled carbon nanotubes on Si(100) substrates

Fleming, L.; Ulrich, Marc; Efimenko, Kirill; Genzer, Jan; Chan, Anthony; Madey, Theodore E.; Oh, Soo‐Jin; Zhou, Otto; Rowe, J. E.

doi:10.1116/1.1775190

Cited by 21 publications

(20 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the plot (a) two prominent spectral features are seen at 285.5 and ~293 eV, correspond-ing to the π* and σ* resonances, respectively [13,14]. This is in agreement with the general electronic structure in π-conjugated carbon materials as probed by XAS spectra of SWCN [28][29][30] and graphite [31]. The similarity between XAS spectra for graphite and SWCN shows clear evidence of the π-conjugated system in SWCN.…”

Section: Hydrogenation Of Single-walled Carbon Nanotubessupporting

confidence: 73%

Hydrogenation of Single-Walled Carbon Nanotubes

et al. 2005

View full text Add to dashboard Cite

Towards the development of a useful mechanism for hydrogen storage, we have studied the hydrogenation of single-walled carbon nanotubes with atomic hydrogen using core-level photoelectron spectroscopy and x-ray absorption spectroscopy. We find that atomic hydrogen creates C-H bonds with the carbon atoms in the nanotube walls and such C-H bonds can be completely broken by heating to 600o C. We demonstrate approximately 65 ± 15 at % hydrogenation of carbon atoms in the single-walled carbon nanotubes which is equivalent to 5.1 ± 1.2 weight % hydrogen capacity. We also show that the hydrogenation is a reversible process.

show abstract

Section: Hydrogenation Of Single-walled Carbon Nanotubessupporting

confidence: 73%

Hydrogenation of Single-Walled Carbon Nanotubes

et al. 2005

View full text Add to dashboard Cite

show abstract

“…NEXAFS spectra from Matrix in parallel and perpendicular (bottom a and b, respectively) orientations. Ranges of emissions have been adapted from Flemming 27 and Hemraj-Benny 14 for CNTs and from Dhez, 26 and Efimenko 25 for polymer emissions.…”

Section: Figurementioning

confidence: 99%

Near-Edge X-ray Absorption Fine Structure Studies of Electrospun Poly(dimethylsiloxane)/Poly(methyl methacrylate)/Multiwall Carbon Nanotube Composites

Larios

Alamgir

et al. 2013

Langmuir

View full text Add to dashboard Cite

This work describes the near conduction band edge structure of electrospun mats of MWCNT-PDMS-PMMA by near edge X-Ray absorption fine structure (NEXAFS) spectroscopy. Effects of adding nanofillers of different sizes were addressed. Despite observed morphological variations and inhomogeneous carbon nanotube distribution, spun mats appeared homogeneous under NEXAFS analysis. Spectra revealed differences in emissions from glancing and normal spectra; which may evidence phase separation within the bulk of the micron-size fibers. Further, dichroic ratios show polymer chains did not align, even in the presence of nanofillers. Addition of nanofillers affected emissions in the C-H, C=O and C-C regimes, suggesting their involvement in interfacial matrix-carbon nanotube bonding. Spectral differences at glancing angles between pristine and composite mats suggest that geometric conformational configurations are taking place between polymeric chains and carbon nanotubes. These differences appear to be carbon nanotube-dimension dependent, and are promoted upon room temperature mixing and shear flow during electrospinning. CH-π bonding between polymer chains and graphitic walls, as well as H-bonds between impurities in the as-grown CNTs and polymer pendant groups are proposed bonding mechanisms promoting matrix conformation.

show abstract

“…The CNT UPS spectrum can be understood as angle integrated spectra of graphene. Since the nanotube is a rolled graphene sheet, photoelectrons ejected from both normal and tangential directions of the nanotube/graphene surface are simultaneously detected [12]. The work function was determined by the intersection of the high binding energy cut-off of the accelerated electrons with the base line of the spectrum (as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Composition, Electronic and Magnetic Investigation of the Encapsulated ZnFe2O4 Nanoparticles in Multiwall Carbon Nanotubes Containing Ni Residuals

et al. 2015

View full text Add to dashboard Cite

We report investigation on properties of multiwall carbon nanotubes (mCNTs) containing Ni residuals before and after encapsulation of zinc ferrite nanoparticles. The pristine tubes exhibit metallic character with a 0.3 eV reduction in the work function along with ferromagnetic behavior which is attributed to the Ni residuals incorporated during the preparation of tubes. Upon encapsulation of zinc ferrite nanoparticles, 0.5 eV shift in Fermi level position and a reduction in both the π band density of state along with a change in the hybridized sp2/sp3 ratio of the tubes from 2.04 to 1.39 are observed. As a result of the encapsulation, enhancement in the σ bands density of state and coating of the zinc ferrite nanoparticles by the internal layers of the CNTs in the direction along the tube axis is observed. Furthermore, Ni impurities inside the tubes are attracted to the encapsulated zinc ferrite nanoparticles, suggesting the possibility of using these particles as purifying agents for CNTs upon being synthesized using magnetic catalyst particles. Charge transfer from Ni/mCNTs to the ZnFe2O4 nanoparticles is evident via reduction of the density of states near the Fermi level and a 0.3 eV shift in the binding energy of C 1 s core level ionization. Furthermore, it is demonstrated that encapsulated zinc ferrite nanoparticles in mCNTs resulted in two interacting sub-systems featured by distinct blocking temperatures and enhanced magnetic properties; i.e., large coercivity of 501 Oe and saturation magnetization of 2.5 emu/g at 4 K.

show abstract

Near-edge absorption fine structure and UV photoemission spectroscopy studies of aligned single-walled carbon nanotubes on Si(100) substrates

Cited by 21 publications

References 14 publications

Hydrogenation of Single-Walled Carbon Nanotubes

Hydrogenation of Single-Walled Carbon Nanotubes

Near-Edge X-ray Absorption Fine Structure Studies of Electrospun Poly(dimethylsiloxane)/Poly(methyl methacrylate)/Multiwall Carbon Nanotube Composites

Composition, Electronic and Magnetic Investigation of the Encapsulated ZnFe2O4 Nanoparticles in Multiwall Carbon Nanotubes Containing Ni Residuals

Contact Info

Product

Resources

About