Enhanced Stability and Hydrogen Storage Capacity of Sc‐Doped B‐Defected h‐BN Monolayer: Insight From DFT and MD Simulation

ABSTRACT In this work, Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations are utilized to study the hydrogen storage potential of a hexagonal boron nitride ( h ‐BN) monolayer doped with a Scandium (Sc) atom. Sc occupies the boron site of h ‐BN with a strong binding energy of −6.8 eV, while a high diffusion barrier limits dopant mobility and inhibits clustering. Also, MD simulation at 300 K confirms the system's thermal stability, and a positive phonon dispersion indicates dynamical stability. By reducing its bandgap from 4.61 to 1.87 eV and introducing new states close to the Fermi level that act as active adsorption sites for H2 molecules, Sc doping significantly changes the electronic properties of pristine h ‐BN. Among the adsorption sites considered, the nitrogen site was found to be the most favorable, exhibiting an adsorption energy of −0.34 eV. The Sc‐doped h ‐BN monolayer could hold up to 9H 2 molecules, achieving a maximum theoretical gravimetric density of 6.58 wt.%. Furthermore, thermodynamic modelling under realistic conditions (30 atm, 25°C for adsorption and 3atm, 100°C for desorption) yields a usable capacity of 4.62 wt.%. These results highlight Sc‐doped h ‐BN monolayers as a stable and efficient reversible hydrogen storage material suitable for clean energy applications.