Computational evaluation of scandium decorated boron oxide monolayer as reversible hydrogen storage medium

Two-dimensional (2D) materials with a high surface-to-volume ratio and excellent electronic properties have been extensively used as hydrogen (H 2 ) storage mediums. In this study, the first-principles calculations have been implemented to explore the structural, electronic and H 2 storage performance of recently synthesized boron monoxide (BO) monolayer decorated with the scandium (Sc) dopants. It is found that doping with three Sc atoms, resulting in the formation of 3Sc@BO material, changes the electronic properties of BO from semiconducting to conducting. The Sc dopants are bonded with the BO in the form of Sc–O bonds with significantly strong binding energies of −4.628, −4.708 and −4.323 eV/Sc, for Sc@BO, 2Sc@BO, and 3Sc@BO, respectively. Thermal stability of the 3Sc@BO system is verified through ab initio molecular dynamics (AIMD) simulations. The H 2 molecules adsorbed on 3Sc@BO are polarized and exhibit the obvious hybridization between H 2 and Sc. Under maximum hydrogenation, the 3Sc@BO could adsorb to a maximum of 19H 2 molecules, resulting in a high storage capacity of 10.96 wt%, and the average adsorption energy is −0.35 eV/H 2 . The adsorption of H 2 on 3Sc@BO is elaborated as a synergistic collaborative amalgamation of physical and chemical adsorption mechanisms. Furthermore, relative energy analysis indicates that H 2 molecules remain adsorbed on 3Sc@BO at 298.15 K and moderate pressures, and the desorption occurs at temperatures above 319 K. Our findings reveal the potential of 3Sc@BO as a high-capacity H 2 storage material. • Synthesized boron monoxide (BO) monolayer investigated as a potential hydrogen (H 2 ) storage material. • BO functionalized with transition metals (Sc, V, Fe) to enhance hydrogen storage performance. • Thermal and structural stability confirmed using ab initio molecular dynamics (AIMD) simulations. • Scandium (Sc) doping gave the highest H 2 storage capacity with exceptional hydrogen uptake.