CSIRO PUBLISHING - Australian Journal of Chemistry

Effects of Nitric Acid and Heat Treatment on Hydrogen Adsorption of Single-Walled Carbon Nanotubes

H. Takagi ^A ^C, Y. Soneda ^A, H. Hatori ^A, Z. H. Zhu ^B and G. Q. Lu ^B

^A National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8569, Japan.
^B ARC Centre for Functional Nanomaterials, School of Engineering, The University of Queensland, Brisbane, QLD 4072, Australia.
^C Corresponding author. Email: hide-takagi@aist.go.jp

Abstract

The effects of nitric acid treatment and subsequent heat treatment on the hydrogen adsorption properties of single-walled carbon nanotube (SWCNT) samples were investigated. The hydrogen adsorption and desorption isotherms of SWCNTs treated with nitric acid alone and SWCNTs treated with nitric acid and then heated were measured at 77 and 303 K over the hydrogen pressure range 0–3.5 MPa. Nitric acid treatment increased hydrogen adsorption by opening the nanotubes and changing the bundle structure. Subsequent heat treatment of the acid-treated SWCNT sample further increased hydrogen adsorption by removing functional groups introduced by the acid treatment.

Australian Journal of Chemistry 60(7) 519–523 doi:10.1071/CH06409
Submitted: 1 November 2006 Accepted: 23 March 2007 Published: 9 July 2007