First-principles study of hydrogen storage on Li-decorated silicene

Abstract

Motivated by experimental developments on silicene, we perform first-principles density functional study on the possibility of hydrogen storage on the Li-decorated silicene. The calculated Li-binding energy on silicene is significantly higher than the Li bulk's cohesive energy, ruling out any possibility of cluster formations in the Li-doped silicene, which facilitate the reversible hydrogen adsorption and desorption. For one Li atom adsorbing on silicene, each Li could adsorb up to five hydrogen molecules. By adsorbing Li atoms on both sides of silicene, the hydrogen capacity can reach as high as 6.35 wt%, and the average binding energy of H2 molecules falls within the range of 0.32-0.17 eV, which is favorable for developing high-capacity hydrogen storage at room temperature. These findings may provide a potential avenue to design new hydrogen storage materials in silicene-based nanoelectronics. © 2013 Springer Science+Business Media Dordrecht.