Hydrogen storage: a comparison of hydrogen uptake values in carbon nanotubes and modified charcoals

¹ Department of Electrical Engineering, Tung-Hai University, No. 181, Taichung Harbor Road, Section 3, Taichung, 40704, Taiwan, R.O.C.
² Institute of Mechanical Engineering, National Kaohsiung University of Application Science, No. 415, Jiangong Road, Sanmin District, Kaohsiung City, 80778, Taiwan, R.O.C.
³ Institute of Electronics Engineering, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan, R.O.C.
⁴ Department of Physics, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan, R.O.C.
⁵ Institute of Nuclear Energy Research, No. 1000, Wenhua Road, Jiaan Village, Longtan, Taoyan, 32546, Taiwan, R.O.C.

Corresponding author: kenymiao@thu.edu.tw

Received: 29 October 2009
Revised: 17 April 2010
Accepted: 4 August 2010
Published online: 29 September 2010

Abstract

We compared the hydrogen uptake weight percentages (wt.%) of different carbonized materials, before and after modification, for their application in hydrogen storage at room temperature. The Sievert's method [T.P. Blach, E. Mac, A. Gray, J. Alloys Compd. 446-447, 692 (2007)] was used to measure hydrogen uptake values on: (1) Taiwan bamboo charcoal (TBC), (2) white charcoal (WC), (3) single-walled carbon nanotubes (SWCNTs) bought from CBT Inc. and (4) homemade multi-walled carbon nanotubes (MWCNTs) grown on TBC. Modified samples were coated with a metal catalyst by dipping in KOH solutions of different concentrations and then activated in a high temperature oven (800 °C) under the atmospheric pressure of inert gas. The results showed that unmodified SWCNTs had superior uptake but that Taiwan bamboo charcoal, after modification, showed enhanced uptake comparable to the SWCNTs. Due to TBC's low cost and high mass production rate, they will be the key candidate for future hydrogen storage applications.