Yttrium-Modified B ₁₂ N ₁₂ Nanocages for High-Performance H ₂ Sensing: Insights from DFT Calculations on Sensitivity, Selectivity, and Recovery

Boron nitride (B₁₂N₁₂) nanocages have attracted considerable attention due to their exceptional structural stability and tunable electronic properties, making them promising candidates for gas-sensing applications. In this study, DFT-D3 calculations at the B3LYP/def2-TZVP level, including relativistic effects for yttrium (SARC-ZORA-def2-TZVP), were employed to investigate H₂ adsorption on pristine and Y-modified (doped, decorated, and encapsulated) B₁₂N₁₂ nanocages. The pristine nanocage exhibited weak physisorption (<i>E</i> _ads = -0.04 eV), whereas the Y@b₆₄ configuration demonstrated strong chemisorption (<i>E</i> _ads = -0.96 eV), pronounced electronic sensitivity (Δ<i>E</i> _gap = 74.94%), and a feasible recovery time (τ = 166.8 s). Analyses of electrostatic potential, molecular dynamics (1000 ps), IR, and UV-vis spectra confirmed the structural robustness and optical detectability of H₂. Furthermore, the Y@b₆₄ nanocage showed remarkable selectivity toward H₂ compared to common interfering gases (CH₄, CO, H₂S, and N₂). Overall, Y@b₆₄ combines high adsorption energy, strong sensitivity, and efficient recovery time, underscoring its potential as a selective, stable, and high-performance H₂ gas sensor.