Ultrahigh hydrogen storage capacity of B3O3 monolayer with electric-field-controlled reversible dehydrogenation

State-of-the-art density functional theory (DFT) calculations were employed to investigate the potential of the newly synthesized porous B 3 O 3 monolayer (ML) for hydrogen storage applications. While pristine B 3 O 3 ML exhibits weak hydrogen adsorption ( E a d s ≅ 0.12 eV per H 2 molecule), its decoration with lithium (Li) or sodium (Na) can significantly enhance the average adsorption energy ( E a d s ≅ 0.32 eV per H 2 molecule). The pore of B 3 O 3 has more capacity towards Li doping, with the ability to accommodate up to six Li atoms, each capable of attracting more than three H 2 molecules, compared to a maximum of only two Na atoms. Ab-initio molecular dynamics (AIMD) simulations confirm the thermodynamic stability of both 6Li@B 3 O 3 and 2Na@B 3 O 3 MLs at room temperature (RT ∼ 300 K). Thermodynamic analysis, based on Langmuir model, showed that the 6Li@B 3 O 3 primitive cell can store approximately 19.26 H 2 molecules, yielding a high effective gravimetric capacity ( C e f f ≅ 16.09 wt% at RT), whereas 2Na@ B 3 O 3 can store about 11.58 H 2 molecules only ( C e f f ≅ 10.07 wt% at RT). Both values are significantly higher than the U.S. Department of Energy's 2025 target of 5.5 wt%. Furthermore, charge transfer analysis based on the Bader method and charge density difference (CDD) has confirmed charge transfer from Li/Na atoms to H 2 molecules, confirming the role of H 2 as charge acceptors. The application of electric fields oriented away from the surface can reduce the adsorption energy, thereby facilitating H 2 desorption. Based on these characteristics, Li- and Na-decorated B 3 O 3 ML stand out as promising candidate materials for hydrogen storage applications. • DFT study of H 2 storage after functionalization of novelly synthesized B 3 O 3 porous 2D material. • Total energy and AIMD confirmed the stability of 6Li@B 3 O 3 and 2Na@B 3 O 3 MLs. • DFT @ 0 K showed the adsorption of 20H 2 and 12H 2 molecules per primitive cell, respectively. • Thermodynamic analysis @ RT showed C e f f ≅ 16 wt% & 10 wt%, respectively. • Application of electric field can give more control on the reversible dehydrogenation.