TITLE:
Multiscale Investigation of Hydrogen Adsorption in Vacancy-Engineered CNCs: A Combined DFT and PHITS Monte Carlo Study
AUTHORS:
Mohammed Ahmed Al-Khateeb, Ahlam El-Barbary
KEYWORDS:
Mono-Vacancy, CNCs, Density Functional Theory, Hydrogen Storage, Surface Reactivity, PHITS Monte Carlo Simulation, Energy Deposition
JOURNAL NAME:
Open Journal of Composite Materials,
Vol.16 No.2,
February
25,
2026
ABSTRACT: The rapid exhaustion of fossil fuel resources, coupled with increasing environmental degradation, has driven the pursuit of sustainable and clean energy carriers. Hydrogen, in particular, has attracted considerable attention as a potential alternative energy medium capable of addressing these challenges, while also aligning with the performance targets established by DOE. This study systematically investigates the synergistic effects of mono-vacancy engineering (V1 at the apex, V2 away from the apex) on the hydrogen adsorption properties of carbon nanocones (CNCs) across five disclination angles (60˚ - 300˚). First-principles DFT calculations (B3LYP/6-31G) reveal that the C89H10-V1-HS2 configuration at a 300˚ disclination angle possesses the most favorable adsorption energy of −4.95 eV, a peak dipole moment of 24.21 D, and a minimum energy gap of 0.02 eV. Complementary Monte Carlo simulations performed via PHITS 3.35 provide a macroscopic validation, demonstrating that these vacancy sites act as focal points for energy localization. The results indicate a maximum localized temperature rise of 34.8 K and an absorbed dose of 0.82 Gy. These findings confirm that vacancy-induced electronic modulation, combined with localized thermal excitation, significantly enhances the hydrogen storage potential of CNCs for irradiation-assisted applications.