Effects of nanostructures on the hydrogen storage properties of MgH2 - A first principles study

Hydrogen storing properties of nanostructured MgH 2 in two phases are investigated through first principles study using density functional theory. It is shown computationally that the hydrogen storage properties of MgH 2 are significantly enhanced by proper engineering of the nanostructure. The nanoparticle clusters of MgH 2 show linear behavior in adsorbing the hydrogen molecules and the binding energy values lie in the range −0.12eV to - 0.15eV. The MgH 2 nanowires show non-linearity in hydrogen adsorption. For certain configuration, the hydrogen molecules binding energy values lie in the useful range (−0.15eV –> −0.27eV). Over all, the nanostructured MgH 2 exhibits good hydrogenation and reduced desorption temperature. Selected configuration of the light metal free standing hydride MgH 2 nanostructure, theoretically shows high hydrogen storage capacity which with suitable substrate is bound to reduce to the useful range of 6.4–8.8 wt%.