Multiwalled carbon nanotubes produced by direct current arc discharge in hydrogen gas

Abstract

Multiwalled carbon nanotubes were produced by direct current (DC) arc discharge in the mixture gas of H 2–N 2. Raman scattering spectroscopy was used to characterize the MWNTs. Radial breathing mode vibration signals were observed at 272 and 388 cm −1. Tangential mode vibration signal was observed at ≈1582 cm −1, and other intense signals were also observed at ≈1860 cm −1for the MWNTs produced in the gas with the H 2 contents exceeding 90%. DC arc discharge in pure D 2 was also carried out, by which it was confirmed that the peak position and intensity of the Raman signal at ≈1860 cm −1 were independent of whether the gas was H 2 or D 2. This suggests that the ≈1860 cm −1 band is not associated with hydrogen-based vibrations.