Chirality-Dependent Combustion of Single-Walled Carbon Nanotubes

Abstract

The chirality-dependent combustion of single-walled carbon nanotubes (SWCNTs) during oxidation in both\nair and hydrogen peroxide was investigated using photoluminescence and Raman spectroscopy. Under air\noxidation conditions, SWCNTs with a higher chiral angle and smaller diameter were observed to decompose\nmore rapidly. The decomposition rate of each chiral index was determined from the reaction rate analysis,\nand it was found that the reaction is governed by a “local curvature radius” along the C−C bond. The reaction\nbarriers for breaking the C−C bonds after cycloaddition with oxygen molecules were obtained for 10 types\nof SWCNTs using first-principles calculations. The barrier heights were found to depend on the local curvature\nradius, which showed good agreement with the experimental results. On the other hand, for the oxidation\nreaction in hydrogen peroxide, oxygen radicals decomposed the smaller-radius SWCNTs more rapidly without\nany chirality selection. As a result, two different chirality distributions for SWCNTs with similar diameters\nwere obtained by these oxidation processes.