Surface Oxidation of Single-Walled Carbon Nanotubes with Oxygen Atoms

摘要

Single-walled carbon nanotube (SWNT) powder was surface oxidized with gaseous oxygen atoms produced by low-pressure: (1) vacuum UV (VUV) (λ = 104.8 and 106.7 nm) photo-oxidation and (2) microwave (MW) plasma discharge of an Ar-O_2 mixture. X-ray photoelectron spectroscopy (XPS) was used to detect the carbon- and oxygen-containing functional groups in the top 2-5 nm of the sample's surface. VUV photo-oxidation showed more of the C-O-C and O-C=O functional groups compared to the carbonyl, C=O, moiety. The results of this study are compared to previous investigations where ozone produced from high-pressure, UV photo-oxidation (λ = 184.9 and 253.7 nm) was mainly reacted with SWNT powder and paper. The presence of UV or VUV radiation shows higher levels of oxidation than the MW results which were conducted in the absence of radiation from the plasma.