A New Class of Scandium Carbide Nanosheet

A new class of two-dimensional scandium carbide nanosheet has been identified by using first-principles density functional theory. It has a primitive cell of Sc(3)C(10), in which there are two pentagonal carbon rings surrounded by one scandium octagon. Being as the precussor of Volleyballene Sc(20)C(60) and ScC nanotubes, the Sc(3)C(10) nanosheet is exceptionally stable. By rolling up this Sc(3)C(10) sheet, a series of stable ScC nanotubes have been obtained. All the nanotubes studied have been found to be metallic. Furthermore, the hydrogen storage capacity of the ScC nanotubes has been explored. The calculated results show that one unit of the (0,3) ScC nanotube can adsorb a maximum of 51 hydrogen molecules, reaching up to a 6.25 wt% hydrogen gravimetric density with an average binding energy of 0.23 eV/H(2).