Noncovalent interaction of single-walled carbon nanotubes with graphene/graphene oxide: Spectroscopy and theoretical characterizations

Abstract

Abstract We present a study of noncovalent coupling of single-walled carbon nanotubes (SWNTs) with graphene/graphene oxide (GO) employing optical spectroscopy (UV–visible optical absorption, Raman spectroscopy), scanning microscopy, and theoretical calculations (molecular dynamics simulations, DFT calculations). The optical absorption of SWNT-GO aqueous solution reveals a transformation of bands corresponding to both SWNTs and GO that can be explained by the formation of nanohybrids of two systems. The spectra showed suppression of the intensities of the bands related to the electronic transitions between the first pair of Van Hove singularities in the electronic density of states of semiconducting SWNTs that was explained by the charge transfer from SWNTs to GO. The nanohybrids are not destroyed after deposition of SWNT-GO aqueous solution on a film. The analysis of Raman spectra of the SWNT-GO film reveals the charge transfer between the components. The strong coupling induces stress and causes structural deformations in the carbon nanostructures. The appearance of this effect is in good agreement with the performed calculations. This work provides new experimental and theoretical results on the energetics and structural characteristics of SWNT-GO nanohybrids which may be scientifically and practically significant as they can be used to elaborate solar cells, batteries, sensors, etc.