Reversible Hydrogen Storage in Metal-Decorated Honeycomb Borophene Oxide

Two-dimensional (2D) boron-based materials are receiving much attention as H₂ storage media due to the low atomic mass of boron and the stability of decorating alkali metals on the surface, which enhance interactions with H₂. This work investigates the suitability of Li, Na, and K decorations on 2D honeycomb borophene oxide (B₂O) for H₂ storage, using dispersion corrected density functional theory (DFT-D2). A high theoretical gravimetric density of 8.3 wt % H₂ is achieved for the Li-decorated B₂O structure. At saturation, each Li binds to two H₂ with an average binding energy of -0.24 eV/H₂. Born-Oppenheimer molecular dynamics simulations at temperatures of 100, 300, and 500 K demonstrate the stability of the Li-decorated structure and the H₂ desorption behavior at different temperatures. Our findings indicate that Li-decorated 2D B₂O is a promising material for reversible H₂ storage and recommend experimental investigation of 2D B₂O as a potential H₂ storage medium.