Synthesis and Raman spectroscopic characterisation of carbon nanoscrolls

Abstract

Raman characteristics of nanoscrolls including the G-peak, the D-peak and new bands in the low-wavenumber region are discussed. Distinct peaks at ∼450 cm −1, ∼600 cm −1, ∼690 cm −1 and ∼870 cm −1 are identified to originate from transverse optic and transverse acoustic phonon branches at the K-point, the M-point and the Γ-point. The Raman spectrum of nanoscrolls is compared with that of highly oriented pyrolytic graphite (HOPG) and the elastic strain in the scrolls due to curvature is estimated analytically to account for the broadening of the G-peak. Synthesis of carbon nanoscrolls by splitting and rupturing graphene planes is also described in detail. The structure and composition of graphene were verified using X-ray diffraction and X-ray photoelectron spectroscopy. The structure of the nanoscrolls was confirmed by electron microscopy.