title: Release of N(2) from the carbon nanotubes via high-temperature annealing.
abstract: Nitrogen (N)-doped carbon nanotubes (CNTs) were heated to 1000 degrees C under an ultrahigh vacuum. X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge structure (XANES) reveal three different N structures; graphitelike, pyridine-like, and molecular N(2). The vibrationally resolved XANES peaks of N(2) were first observed, suggesting the existence of molecular N(2) as intercalated and trapped forms. The annealing process can decrease the average N content from 6.3 at. % to 3.3 at. %, mainly by releasing molecular N(2). Electron energy-loss spectroscopy (EELS) confirms that the annealing releases molecular N(2) from the CNTs.
authors.affiliation: Department of Chemistry, Korea University, Jochiwon 339-700, South Korea.
authors.forename: Hyun Chul
authors.initials: HC
authors.lastname: Choi
authors.forename: Seung Yong
authors.initials: SY
authors.lastname: Bae
authors.forename: Woo-Sung
authors.initials: WS
authors.lastname: Jang
authors.forename: Jeunghee
authors.initials: J
authors.lastname: Park
authors.forename: Ha Jin
authors.initials: HJ
authors.lastname: Song
authors.forename: Hyun-Joon
authors.initials: HJ
authors.lastname: Shin
authors.forename: Hyunsung
authors.initials: H
authors.lastname: Jung
authors.forename: Jae-Pyoung
authors.initials: JP
authors.lastname: Ahn