A green and economical vapor-assisted ozone treatment process for surface functionalization of carbon nanotubes. Issue 4 (6th January 2017)

• Record Type: Journal Article
• Authors: Luo, Jingjie; Liu, Yuefeng; Wei, Hua; Wang, Bolun; Wu, Kuang-Hsu; Zhang, Bingsen; Su, Dang Sheng
• Is Part Of: Green chemistry. Volume 19:Issue 4(2017)
• Page Start: 1052
• Page End: 1062
• Publication Date: 2017-01-06
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/c6gc02806c
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : We report herein a green and economical strategy for oxidative modification of carbon nanotubes (CNT) by a facile ozone treatment in the presence of solvent vapor (H2 O, 30% H2 O2 solution and ethanol). Abstract : We report herein a green and economical strategy for oxidative modification of carbon nanotubes (CNT) by a facile ozone treatment in the presence of solvent vapor (H2 O, 30% H2 O2 solution and ethanol). This procedure is able to introduce a considerable level of oxygen groups with a dominant population of carboxyl groups at near ambient temperature. The optimization study of the process provides the reaction temperature and time, as well as the source and partial pressure of the vapor, key parameters determining the oxidation efficiency. The process efficiency and sustainability are assessed to compare with conventional oxidative treatment ( e.g., nitric acid oxidation). Ozone treatment assisted by water or H2 O2 /H2 O vapor can introduce abundant oxygenated groups on the sidewalls of CNT, and the process with H2 O2 /H2 O vapor can deliver a much higher selectivity towards carboxyl species on the sidewalls of CNT. With the appropriate functionalization temperature (40 °C) and incremental partial pressure of vapor, the surface defect and oxygen content on the CNT could be dramatically increased. The ozone treated CNT can be used for diverse applications such as metal-free catalyst and support; the modified CNT display higher activity for the ring-opening reaction of styrene oxide than HNO3 treated CNT and develop strong interaction for anchoring iron oxide nanoparticles even up to 350 °C. This ozone treatment in the presence of vapor could also be accomplished by using compressed air as the carrier gas, which can be considered an efficient and eco-friendly functionalization process.