Clustering of functional molecules on a single-walled carbon-nanotube surface and its effect on hydrogen storage

• Published in: Physica status solidi. B. Basic research 2009-10, Vol.246 (10), p.2248-2256
• Main Authors: Iyakutti, K., Surya, V. J., Rajarajeswari, M., Venkataramanan, N. S., Kawazoe, Y.
• Format: Article
• Language: English
• Subjects: 61.48.De; 71.15.Nc; 73.22.−f; 84.60.Ve; Alternative fuels. Production and utilization; Applied sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Energy; Exact sciences and technology; Fuels; Hydrogen; Materials science; Nanoscale materials and structures: fabrication and characterization; Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Nanotubes; Physics; Structure of solids and liquids; crystallography
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.200945314

This first‐principles study deals with the effect of clustering of different functional molecules adsorbed on the surface of the single‐walled carbon nanotubes (SWCNTs) (5, 5). Here we report the results of our investigation on the effect of clustering on storage capacity, the nature of H2 bonding and strength of H2 binding. The investigation is carried out for (5, 5) SWCNT functionalized with different types of hydrogen‐rich molecules such as AlH3, NH3, BH3 and NiH2. In the case of AlH3, the clustering turns into dimerization with the adsorption of H2. This is distinctly different from the other three cases. Weak clustering is observed for full coverage of NH3 molecules. The clustering starts with higher coverage of H2 molecules in the case of SWCNT functionalized with BH3 molecules. The clusters of NiH2 molecules, chemisorbed on the surface of carbon nanotube, are observed. Our study indicates that depending upon the materials used for the functionalization, the clustering pattern is different and the effect on the above‐mentioned factors is also different.