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Schlagwörter:
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Zusammenfassung:
We have performed first-principles DFT calculations
to explore the possibility of using a metal-functionalized
hydrogenated BN sheet for storage of molecular hydrogen. The
chair BHNH conformer is ideally suited for adsorption of metal
adatoms on the surface of the sheet. The Li metal, in particular,
binds to the sheet with a binding energy (∼0.88 eV/Li atom)
and becomes cationic, which thereby attracts hydrogen molecules.
However, the interaction of the BHNH sheet and the
absorbed H2 molecules with Li+ is different from the conventionally
known Dewar coordination or Kubas-type interaction
for hydrogen storage. Each Li+ can adsorb up to four H2
molecules, and the hydrogen binding energy is in the desired
energy window for effective storage of molecular hydrogen. The fully Li-functionalized BHNH sheet yields a reasonably high
gravimetric density, which is more than 7 wt %.