Highly symmetrical B12@Mg20C12 with icosahedral B12 motif: A potential hydrogen storage medium

Abstract

A highly symmetrical core–shell Ih B12@Mg20C12 structure containing icosahedral B12 motif has been proposed in the framework of density functional theory. The core–shell B12@Mg20C12 structure has good kinetic and thermodynamic stability, which is verified by vibrational frequency analysis and molecular dynamics simulations, respectively. The analysis of the electronic structure shows that multiple atoms are connected into a whole by multi-center two-electron σ bonds, which is also the fundamental reason for the structure stability. Raman and photoelectron spectroscopy are simulated theoretically to provide characterizations for future experiments. The core–shell B12@Mg20C12 structure is a potential hydrogen storage material, which can absorb about 72 H2 molecules with a hydrogen capacity as high as 16.0 wt%.

Keywords

• Hydrogen storage
• Core-shell structure
• Density functional theory calculation