The Raman and absorption spectra of carbon nanotubes confined inside zeolite

Single wall carbon nanotubes (SWCNs) of mono size and unique chirality are fabricated by pyrolysis of tripropylamine (TPA) molecules. These SWCNs are confined inside the 1 nm-sized channels of zeolite AFI crystal. Micro-Raman scattering of these SWCNs is done and the specific radial-breathing mode which is unique for carbon nanotubes are observed. Also, Alg, Elg, and E2g, vibration modes are identified. Furthermore, the UV-visible absorption spectrum of these nanotubes is also measured. A broad absorption band with a center energy at 3.7 eV is being observed, which is attributed to the inter-band transition of the one-dimensional nanotube. This result agrees well with the band structures calculated using the tight binding model