Hexagonal boron nitride (h-BN) nanosheet as a potential hydrogen adsorption material: A density functional theory (DFT) study

Abstract The hydrogen storage capacity of Boron Nitride nanosheet has been performed by using density functional theory (DFT). All the structural and electronic properties of a monolayer BN nanosheet are in well agreement with the previously reported results. Out of the four possible adsorption sites, centre is the most favourable adsorption site for H 2 molecule with binding energy ∼ 0.212  eV/H 2 . We have proceeded our calculations considering this adsorption site. The calculated direct band gap within GGA and HSE for pristine h -BN monolayer are found to be 4.669 eV and 5.63 eV, respectively. In our calculation the Hydrogen storage capacity of BN nanosheet was found to be 6.7 wt.% well within benchmark value (6.0%) with an average adsorption energy of ( ∼ 0.128  eV/H 2 ). Bader analysis revealed that the charge transfer from BN nanosheet to the H 2 molecule is very low (0.004–0.065 ∣ e ∣ ) leading to weak binding of the H 2 molecule. The calculated desorption temperature was found to be low due to low average adsorption energy of the H 2 molecule. Also, upon increasing the number of H 2 molecule adsorption a feeble tuning of the band gap has been observed due to the contribution of the 1 s orbital of H 2 molecule.