Novel Method of Evaluating the Purity of Multiwall Carbon Nanotubes Using Raman Spectroscopy

Abstract

We propose the quantitativemethod of evaluating the purity ofmultiwall carbon nanotubes(MWCNTs) using Raman spectroscopy. High purityMWCNTswere prepared by chemical vapor deposition (CVD) to be used as a reference material with 100% purity. Since the intensity and wavenumber of D-band located at around 1500 cm−1 were found to be independent of the excitation wavelength of a laser, the purity of MWCNTs was measured by comparing the intensity ratio of D-band to G-band (

/ ) of the sample with that of a reference material. The established method was verified by testing the mixture of amorphous carbon particles and reference MWCNTs.