Characterization of single-walled carbon nanotubes containing defects from their local vibrational densities of states

Surface-enhanced Raman scattering from small numbers of purified and oxidised single-walled carbon nanotubes

“…SERRS spectra with randomly fluctuating peak intensities and positions in the 1000 to 1200 cm -1 frequency range have been observed. A series of peaks in this window coincides with peak positions that have been assigned to arise from defects on the nanotubes surface [16,18]. We find that these peaks also occur for chemically treated SWCNTS.…”

“…1.5 and 1.3 nm. Theoretical calculations by Vandescuren et al predicted Raman peaks for STW defects for (10, m) (where m is an integer between 0 and 10) nanotubes and for heptagonal-pentagonal defects for (9,0) and (12,0) nanotubes [18]. The SERRS study here potentially probes both (10, m) and (12,0) nanotube type as evidenced by the RBM spectra (see above).…”

“…Studies of defects in nanotubes such as STW have been performed by Fujimori et al and Vandescuren et al [16,18]. Fujimori et al reported temporally fluctuating SERRS spectra from SWCNTs with peaks in the D and G band regions and also peaks outside this region at 1139 and 1184 cm -1 which were assigned to dynamic reconstruction of defective structures of SWCNTs arising from STW defects in the vicinity of SERRS-active sites under irradiation of the laser light [16].…”

“…These kinds of defects refer to the presence of ring sizes other than hexagons, e.g. pentagons, hexagons, or octagons [16][17][18]. One such topological defect is adjacent pentagon/heptagon pairs, called Stone-Thrower-Wales (STW) and heptagonalpentagonal intramolecular junction defects [16,18].…”

“…pentagons, hexagons, or octagons [16][17][18]. One such topological defect is adjacent pentagon/heptagon pairs, called Stone-Thrower-Wales (STW) and heptagonalpentagonal intramolecular junction defects [16,18]. As outlined by Miyamoto et al a STW defect consists of a localised /2 rotation of a C-C bond, such that two pentagons and heptagons are created [19].…”