Potential High-Capacity Hydrogen Storage Medium: Hydrogenated Silicon Fullerenes

Abstract

Searching for hydrogen storage materials suitable for applications has been the focus of extensive research in industry and academia. With the great success in obtaining stable hollow silicon-based nanostructures, one is naturally led to wonder whether silicon-based nanostructures are possible for chemical hydrogen storage. Here a hydrogenated silicon fullerene (HSF), Si60H60, is considered as a prototype of stable silicon-based nanostructures for hydrogen storage. By performing density functional theory calculations we show that the HSF is stable over hydrogen molecule attack and thus qualified for acting as a potential hydrogen storage medium. The interaction between the HSF with hydrogen molecules is found to be essentially via van der Waals force, making the HSF prefer storing hydrogen in molecular form. It is demonstrated that up to 58 hydrogen molecules can be stored into its interior cavity, and together with 60 hydrogen atoms in the exterior surface, total gravimetric density of hydrogen of 58H2@S...