Selective decorating of BC3 and C3N nanosheets with single metal atom for hydrogen storage

Abstract

Employing first-principles calculations, we have studied the structure, stability and hydrogen storage efficiency of pristine and defective BC3 and C3N monolayer functionalized by a variety of single metal adatoms. It is found that single Sc adatom, acting as an optimal dopant on perfect BC3 monolayer, is able to adsorb up to nine H2 molecules as strongly as around 0.24 eV/H2, which allows for a hydrogen storage capacity of 7.19 wt% for Sc atoms stably adsorbing on double sides of BC3 monolayer with eighteen H2 molecules (18H2@2Sc/BC3). Moreover, the desorption temperature and thermodynamical stability of multiple H2 adsorbed Sc-decorated BC3 sheet have been addressed and the saturate configuration of 18H2@2Sc/BC3 is predicted to be stable at mild temperatures and pressures, i.e. less than 250 K at 1 bar, or larger than 24 bar at room temperature. This study indicates that the Sc-decorated BC3 monolayer could be a potential H2 storage candidate, and provides an instructive guidance for designing metal-functionalized carbon-based sheets in hydrogen storage.