Computational study of Fe- and Mn-decocted hexagonal boron nitride for hydrogen storage applications

Hydrogen storage has garnered significant research attention in recent times due to the favorable qualities of hydrogen as a clean energy reservoir. We adorned hexagonal boron nitride (h-BN) with Fe and Mn to employ it for hydrogen storage purposes. Density functional theory (DFT) utilized to investigate diverse properties, encompassing the hydrogen storage capabilities of h-BN modified with both Fe and Mn. Simulation results revealed that, in its unaltered state, h-BN forms weak van der Waals interactions with H2 molecules, leading to a binding energy within the range of 0.28 eV and a desorption temperature below 200 K. Furthermore, the study seeks to evaluate the structural stability, electronic characteristics, adsorption tendencies, binding energies, and hydrogen storage capacity. Adsorption energies of H2 molecules on Fe- and Mn-decorated h-BN falls within the practical range of −0.20 to −0.20 eV for 1H2 to 14H2 molecules and −0.17 to −0.20 eV for 1H2 to 17H2 molecules respectively making them appropriate for H2 storage applications. Additionally, hydrogen storing capacity values for Fe- and Mn-decorated h-BN are 6.77 wt % for 14H2 molecules and 7.03 wt %, for 17H2 molecules respectively. Hybridization was observed between the states of H2 and the d states of the system. At elevated temperatures, the molecular dynamics simulations using AIMD techniques significantly enhanced the thermal stability of hydrogen (H2) molecules when they were adsorbed onto h-BN surfaces decorated with both Fe and Mn, outperforming other experimental conditions or configurations. Based on desorption temperature prediction from the Van't Hoff equation, Fe- and Mn-decorated h-BN exhibit potential as substrate materials for H2 storage by moderately high temperatures. The results of our current work make recognized that Fe/Mn decorated h-BN monolayers are strong eye-getting base material for hydrogen capacity exhibitions at high temperatures.