Structural, electronic and spectral properties referring to hydrogen storage capacity in binary alloy ScBn (n = 1-12) clusters

Based on the DFT calculations within GGA approximation, we have systematically studied the ScBn (n = 1-12) clusters and their hydrogen storage properties. The results show that the maximal adsorption for H2 molecules is ScB7 6H2 structure with the hydrogen storage mass fraction about 9.11%. For ScBn·mH2 clusters as n = 7 or 9-12, the average binding energies between 0.202 and 0.924 eV are suggestively conducive to hydrogen storage. In these medium clusters, the moderate adsorption strength can benefit application of hydrogen energy owning to easily adsorption and dissociation on H2 molecules at room temperature and 1 bar pressure. Furthermore, the absorption spectrum is also investigated from TDDFT calculation. An obvious red-shift of spectral lines at 4.2 eV or 5.6 eV is detected with the increase of number of H2 molecules. It can be regard as 'fingerprint' spectrum in experiment to indicate adsorption capacity of H2 molecules for ScBn·mH2 nanostructures.