Hydrogen Storage in Single-Walled Carbon Nanotubes at Room Temperature
C. Liu,
1
Y. Y. Fan,
1
M. Liu,
1
H. T. Cong,
2
H. M. Cheng,
1*
M. S. Dresselhaus
3*
Masses of single-walled carbon nanotubes (SWNTs) with a
large mean diameter of about 1.85 nanometers, synthesized by a
semicontinuous hydrogen arc discharge method, were employed for
hydrogen adsorption experiments in their as-prepared and pretreated
states. A hydrogen storage capacity of 4.2 weight percent, or a
hydrogen to carbon atom ratio of 0.52, was achieved reproducibly at
room temperature under a modestly high pressure (about 10 megapascal)
for a SWNT sample of about 500 milligram weight that was soaked in
hydrochloric acid and then heat-treated in vacuum. Moreover, 78.3 percent of the adsorbed hydrogen (3.3 weight percent) could be released
under ambient pressure at room temperature, while the release of the residual stored hydrogen (0.9 weight percent) required some heating of
the sample. Because the SWNTs can be easily produced and show reproducible and modestly high hydrogen uptake at room temperature, they show promise as an effective hydrogen storage material.
1 Institute of Metal Research, Chinese Academy
of Sciences, 72 Wenhua Road, Shenyang 110015, China.
2 State Key Lab for Rapidly Solidified
Non-equilibrium Alloys, Institute of Metal Research, Chinese Academy of
Sciences, 72 Wenhua Road, Shenyang 110015, China.
3 Department of Physics and Department of Electrical
Engineering and Computer Science, Massachusetts Institute of
Technology, Cambridge, MA 02139, USA.
*
To whom correspondence should be addressed. E-mail:
cheng{at}imr.ac.cn (H.M.C.) and millie{at}mgm.mit.edu
(M.S.D.)
