Solid-state 13C NMR assignment of carbon resonances on metallic and semiconducting single-walled carbon nanotubes.
Solid-state (13)C NMR spectroscopy was used to investigate the chemical shift of nanotube carbons on m- and s-SWNTs (metallic and semiconducting single-walled nanotubes) for samples with widely varying s-SWNT content, including samples highly enriched with nearly 100% m- and s-SWNTs. High-resolution (13)C NMR was found to be a sensitive probe for m- and s-SWNTs in mixed SWNT samples with diameters of approximately 1.3 nm. The two highly enriched m- and s-SWNT samples clearly exhibited features for m- and s-SNWT (13)C nuclei (approximately 123 and 122 ppm, respectively) and were successfully fit with a single Gaussian, while five mixed samples required two Gaussians for a satisfactory fit.
Engtrakul
Chaiwat
C
National Renewable Energy Laboratory, Golden, Colorado 80401, USA. Chaiwat.Engtrakul@nrel.gov
Davis
Mark F
MF
Mistry
Kevin
K
Larsen
Brian A
BA
Dillon
Anne C
AC
Heben
Michael J
MJ
Blackburn
Jeffrey L
JL