Hydrogen storage and release by bending carbon nanotubes

Efficient storage of hydrogen at room temperature is a bottleneck problem for hydrogen-based energy applications. A simple way of hydrogen storage and release by bending carbon nanotubes (CNTs) at room temperature is demonstrated using molecular dynamics (MD) simulations. A large number of hydrogen molecules can be put in CNTs at low temperatures, and then the hydrogen molecules can be completely encapsulated in the CNTs by bending the CNTs to a critical angle. The critical angle decreases with increasing CNT length, while it increases with increasing hydrogen number and temperature. However, the CNT chirality has a negligible influence on the critical angle and hydrogen storage process. It is demonstrated that the release of the hydrogen molecules also can be controlled accurately at room temperature by changing bending angle. The van der Waals force plays an important role in the hydrogen storage and release process. Compared with the conventional methods for hydrogen storage, the brand-new one occurs at room temperature and the release of the hydrogen molecules can be controlled accurately by changing bending angle. Besides, the special structure of the bent CNTs will also significantly enhance their applications in atomic storage, various chemical and biological sensors and actuators, catalyst and catalyst supports, nanoelectronic devices as well as high-capacity energy storage in solar cells or fuel cells. (C) 2012 Elsevier B.V. All rights reserved.