Calcium doped graphane as a hydrogen storage material

On the basis of first principle density functional theory, we have studied the stability, electronic structure, and hydrogen storage capacity of a monolayer calcium doped graphane (CHCa). The stability of CHCa was further investigated using the ab initio molecular dynamics study. The binding energy of Ca on graphane sheet was found to be higher than its bulk cohesive energy, which indicates the stability of CHCa. It was observed that with a doping concentration of 11.11% of Ca on graphane sheet, a reasonably good H₂ storage capacity of 6 wt. % could be attained. The adsorption energies of H₂ were found to be 0.1 eV, within the range of practical H₂ storage applications.