title: Type- and species-selective air etching of single-walled carbon nanotubes tracked with in situ Raman spectroscopy.
abstract: The thermal oxidation of carbon nanotubes in air is investigated by in situ Raman spectroscopy. Etching rates are directly seen to be diameter, chirality, and type dependent. We directly track the evolution of bundled nanotube networks that undergo air etching from 300 to 600 °C. Some species are more robust than others. Changes to radial breathing mode (RBM) and G- peak structures suggest that metallic species etch away more rapidly, with smaller diameter semiconducting species etching more slowly and large diameter nanotubes, including semiconductors, etching last. The decay in integrated G and D band intensities is tracked and fit reasonably well with biexponential decay. The RBM evolution is better represented by a single exponential. All bands are fit to activation plots with RBMs showing significantly different rates.
authors.affiliation: National Research Council Canada, Building M-50, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Li-Pook-Than
authors.forename: Jacques
authors.initials: J
authors.lastname: Lefebvre
authors.forename: Paul
authors.initials: P
authors.lastname: Finnie