Temperature dependent evolution of the local electronic structure of atmospheric plasma treated carbon nanotubes: Near edge x-ray absorption fine structure study

Journal Article · Fri Sep 01 00:00:00 EDT 2006 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2260821· OSTI ID:20884696

Roy, S S; Papakonstantinou, P; Okpalugo, T I. T.; Murphy, H ^[1]

---

1. School of Electrical and Mechanical Engineering, University of Ulster at Jordanstown, Newtownabbey, County Antrim BT37 OQB, Northern Ireland (United Kingdom)

Near edge x-ray absorption fine structure (NEXAFS) spectroscopy has been employed to obtain the temperature dependent evolution of the electronic structure of acid treated carbon nanotubes, which were further modified by dielectric barrier discharge plasma processing in an ammonia atmosphere. The NEXAFS studies were performed from room temperature up to 900 deg. C. The presence of oxygen and nitrogen containing functional groups was observed in C K edge, N K edge, and O K edge NEXAFS spectra of the multiwalled carbon nanotubes. The N K edge spectra revealed three types of {pi}* features, the source of which was decisively identified by their temperature dependent evolution. It was established that these features are attributed to pyridinelike, NO, and graphitelike structures, respectively. The O K edge indicated that both carbonyl (C=O), {pi}*(CO), and ether C-O-C, {sigma}*(CO), functionalities were present. Upon heating in a vacuum to 900 deg. C the {pi}*(CO) resonances disappeared while the {sigma}*(CO) resonances were still present confirming their higher thermal stability. Heating did not produce a significant change in the {pi}* feature of the C K edge spectrum indicating that the tabular structure of the nanotubes is essentially preserved following the thermal decomposition of the functional groups on the nanotube surface.

• OSTI ID: 20884696
• Journal Information: Journal of Applied Physics, Vol. 100, Issue 5; Other Information: DOI: 10.1063/1.2260821; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
AMMONIA
CARBON
CARBONYLS
DIELECTRIC MATERIALS
ELECTRIC DISCHARGES
ELECTRONIC STRUCTURE
ETHERS
FINE STRUCTURE
NANOTUBES
NITROGEN
OXYGEN
PLASMA
PYROLYSIS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
X-RAY SPECTROSCOPY