Enhancement of energy storage capacity of Mg functionalized silicene and silicane under external strain

The electronic structure, stability, and hydrogen storage capacity of strain induced Mg functionalized silicene (SiMg) and silicane (SiHMg) monolayers have been studied by means of van der Waals induced first principles calculations. A drastic increase in the binding energy of Mg adatoms on both the monolayers under the biaxial symmetric strain of 10% ensures the uniform distribution of dopants over the substrates. A significant positive charge on each Mg accumulates a maximum of six H₂ molecules with H₂ storage capacity of 8.10% and 7.95% in case of SiMg and SiHMg, respectively. The average adsorption energy for H₂ molecules has been found ideal for practical H₂ storage materials.