Exploring Ti-decorated boron phosphide monolayer with chemical modification for efficient hydrogen storage: a DFT and AIMD study

Hydrogen is widely recognized as a promising clean energy carrier. However, the development of efficient, stable, and reversible storage materials remains a significant challenge. In this study, first-principles calculations are employed to explore the structural, energetic, and electronic properties of defect-engineered boron phosphide (BP) monolayers for hydrogen storage. Among the systems investigated, the boron–phosphorus–aluminum defect structure (SVBPAl) demonstrated the highest thermal stability and strongest adsorption behavior, as confirmed by AIMD simulations and binding energy analysis. To enhance hydrogen uptake, SVBPAl was functionalized with various metals (X = Ti, Mg, Ca, Li, Na). The binding energies exceeded the bulk cohesive energies, ensuring stable anchoring and preventing clustering. Notably, the 2Ti-decorated SVBPAl system reversibly adsorbed up to 20H₂ molecules, with adsorption energies between (−0.2 and − 0.6 eV per H₂) and a gravimetric capacity of 7.61 wt%. NEB and desorption temperature confirmed reversible hydrogen release, highlighting SVBPAl-based systems as promising storage candidates.