Insights of Ti-doping on the hydrogen adsorption properties of the 2D-BeN4 monolayer: A density functional investigation

Abstract

We examined the hydrogen storage properties of Ti-doped 2D-Beryllonitrene (2D-BeN4) using Density Functional Theory (DFT). Bader charge analysis revealed charge transfer from titanium to BeN4 and H2 molecules. TiBeN4 and 2Ti–BeN4 complexes showed Kubas interactions, allowing the binding of multiple hydrogen molecules with average adsorption energies between −0.360 eV/H2 and -0.371 eV/H2, and desorption temperatures of 460 K and 475 K respectively, meeting DOE standards. NEB studies indicated binding energies of −2.06 eV and −2.09 eV between Ti and BeN4 in TiBeN4 and 2Ti–BeN4 respectively, which are lower than the diffusion barrier energy, suggesting that there is no possibility of hoping of Ti atom from one hexagonal caped position to another equivalent position. Spin-polarized PDOS revealed induced magnetism in TiBeN4. Calculated adsorption isotherms (H2 uptake graphs) at various pressures align with DOE norms. The electronic structure analysis highlights Ti-doped BeN4 monolayers as promising materials for hydrogen storage applications.