DFT insights into hydrogen storage potential of pristine and metal decorated B12C12 nanocages

The increasing global demand for clean and sustainable energy has intensified interest in efficient hydrogen storage materials, as hydrogen is considered a promising next-generation alternative fuel for future energy systems. This research investigates hydrogen storage properties of pristine and metal-decorated (Li, Ni, Sc, Ti) B 12 C 12 nanocages through density functional theory (DFT) computational analysis performed at the B3LYP-D3/6-31G(d, p) level. This research used multiple analysis, including adsorption energy (E ads ), frontier molecular orbital (FMO), natural bond orbital (NBO), non-covalent interaction (NCI), quantum theory of atoms in molecules (QTAIM), density of states (DOS), and sensing mechanism. Substitutional doping procedures resulted in substantial improvements in the operational capabilities of B 12 C 12 nanocages. The Ti and Sc dopants yielded adsorption energies reaching − 1.222 eV and − 0.251 eV in H2@Ti-BC and H2@Sc-BC, respectively, with the markedly stronger Ti-BC value indicative of near-covalent chemisorption that limits its suitability for reversible hydrogen release. The energy gap (E g ) became more reduced in H2@Li-in-BC (1.213 eV) and H2@BC (1.384 eV), indicating enhanced reactivity, which matched the improved sensitivity and conductivity patterns. The results from NBO analysis showed that H2@Sc-BC and H2@Ti-BC systems exhibited strong donor-acceptor behavior through evaluation of orbital interactions, which was validated by the NCI and QTAIM plots that measured electron density shifts and the nature of interactions. Most systems exhibited increased electrical conductivity, particularly H2@Li-in-BC (6.22 × 10 12 S/m) after hydrogen addition, and work function changes confirmed the direction of charge transfer. Overall, the combined electronic, structural, and adsorption analyses demonstrate that metal-decorated B 12 C 12 nanocages, especially Sc doped BC, are promising candidates for efficient and reversible hydrogen storage technologies.