title: Opening mechanism of internal nanoporosity of single-wall carbon nanohorn.
abstract: Single-wall carbon nanohorn (SWNH), which is a tubular particle with a cone cap, was oxidized in an oxygen flow at various temperatures. N(2) adsorption at 77 K, thermogravimetry (TG), differential thermal analysis (DTA), transmission electron microscopy, and Raman spectroscopy measurements were carried out on the oxidized SWNHs. The specific surface area of the oxidized SWNHs can be controlled by oxidation temperature, giving the maximum value of 1420 m(2)/g. The pore size distribution by the BJH method and the comparison plot of the N(2) adsorption isotherms of SWNH oxidized at different temperatures against that of as-grown SWNH revealed the minimum oxidation temperature for opening internal nanopores. TG-DTA analyses determined the components of as-grown SWNH: amorphous carbon 2.5 wt %, defective carbon at the cone part 15 wt %, tubular carbon 70 wt %, and graphitic carbon 12 wt %. These systematic analyses provided the exact internal nanopore volume of 0.49 mL/g for pure SWNH particles.
authors.affiliation: Center for Frontier Electronics and Photonics, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan.
authors.forename: Shigenori
authors.initials: S
authors.lastname: Utsumi
authors.forename: Jin
authors.initials: J
authors.lastname: Miyawaki
authors.forename: Hideki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hattori
authors.forename: Takaomi
authors.initials: T
authors.lastname: Itoi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ichikuni
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Kanoh
authors.forename: Masako
authors.initials: M
authors.lastname: Yudasaka
authors.forename: Sumio
authors.initials: S
authors.lastname: Iijima
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kaneko