Regresar

Raman and XPS analyses of pristine and annealed N-doped double-walled carbon nanotubes

Abstract:

Nitrogen-doped single/multi-walled carbon nanotubes (CNTs) have been studied for a long time from synthesis to properties. However, the stability of N in the CNT lattice still needs further development. In this work, N-doped double-walled (DW) CNTs were synthesized using benzylamine as C and N sources. In order to test the stability of N-doped DWCNTs, high-temperature annealing in vacuum was performed. By XPS and Raman spectroscopic measurements, we found that the N-doped DWCNTs are still stable under 1500{ring operator}C. The amounts of pyrrolic and molecular N decrease after the annealing due to the release effect. However, the amounts of pyridinic and graphitic N greatly increase. Also, the N ratio of the outer tubes increases much more than that of the inner tubes, suggesting that N atoms from the surrounding N-containing materials combine into the CNT structure during the annealing. © 2015 WILEY-VCH Verlag GmbH