Studies of Multiwall Carbon Nanotubes Using Raman Spectroscopy and Atomic Force Microscopy

Abstract

Preliminary results of Raman scattering measurements of multiwall carbon nanotubes (MWCNT) are presented. The nanotubes have been carefully dissolved, separated and then characterized by AFM. The micro-Raman spectra are taken with 514,5nm wavelength excitations in the range 4K - 400K. Basically the spectra are quite similar to the well known single wall carbon nanotube spectra, but the low frequency band is absent. The major Raman bands, observed in single wall nanotubes are found in the spectra. In particular the disorder effects are visible due to the pronounced D band at ~1350 cm-1. Metallic and semiconducting type of conductivity is distinguished through analysis of the G (LO) mode at ~1600 cm-1. A new feature in these spectra exists at ~843 cm-1. Low energy radial breathing mode absence has been explained.

The influence of ZrO2promoter in Pd/fCNDs-ZrO2catalyst towards alcohol fuel electrooxidation in alkaline media

“…The G(graphite), D(disorder) bands and their second-order harmonic (G' band) clearly appear at 1577 cm −1 , 1350 cm −1 and 2696 cm −1 respectively. The position of our Raman peaks is in good agreement with other studies and theoretical calculations for single walled nanotubes suggesting that the vibration structure of MWCNT is quite similar to that of single walled nanotubes [39,42]. The similarities in the Raman spectra of MWCNT and CNDs indicates that pulverizing does not destroy the graphitic structure of MWCNT.…”

“…The G-band is a characteristic feature of the graphitic layers and corresponds to the tangential vibration of carbon atoms. Another characteristic feature of carbon materials is the presence of the D-band which corresponds to the vibration of defective graphitic structures [36][37][38][39][40][41][42][43][44]. The I G /I D ratio is often used to measure the quality of a sample, however, other researchers have argued that this method cannot be used as a standardized evaluation of sample quality because the intensity of D-band is dependent on the wavelength of the laser source [41].…”

Novel intensified nano-structured zero-valente nickel alloy based catalyst for hydrogen production via methane catalytic decomposition

“…The peaks exhibited in Fig. 11 can also refer to the formation of carbon nano-fiber (CNF) along with the carbon nano-particles [55,56]. This can verify the ability of catalyst A in decomposing CH 4 into carbonceous materials while producing hydrogen.…”

Recycling old screen-printed electrodes with newly designed plastic antibodies on the wall of carbon nanotubes as sensory element for in situ detection of bacterial toxins in water

“…This corroborated well the presence of a polymeric layer on the overall CNTs structures. In addition, a small feature called G2 or D near 1610 cm −1 was observed in the modified CNTs, characteristic of large diameter distribution of the CNTs [51].…”