Abstract
The electronic structure of purified single-wall carbon nanotubes obtained from HiPco process has been probed by X-ray fluorescent spectroscopy. The CKα spectrum of the HiPco nanotubes revealed a significant enhancement of the high-energy maximum intensity compared with the graphite spectrum. Quantum chemical calculations of carbon nanotube models show the spectral variations could be caused by vacancies in the tube walls developed with the thermal and acid treatment of the sample. © 2003 Elsevier Ltd. All rights reserved.