Interface engineering between two-dimensional materials and magnesium borohydride to synergistically optimize its...

The practical application of Mg(BH₄)₂ for hydrogen generation via hydrolysis is constrained by a fundamental "seesaw effect," wherein improvements in hydrolysis kinetics typically come at the expense of hydrogen capacity. To break this trade-off, multiphase interfaces are constructed by in situ growth of γ-Mg(BH₄)₂ (MBH) on a two-dimensional Ti₃C₂ MXene (TC) and graphene oxide (GO). This interfacial engineering strategy exploits spatial confinement to direct MBH crystallization and promotes interfacial charge transfer. The resulting Ti₃C₂ MXene@Mg(BH₄)₂ (TC@MBH) and GO@Mg(BH₄)₂ (GO@MBH) composites exhibit synergistic enhancement, delivering high hydrogen yields of 1311.8 ± 40.5 and 1307.3 ± 32.3 mL/g (gravimetric capacity of 11.7 ± 0.4 wt%), which is accompanied by moderated hydrolysis kinetics and enhanced air stability. Density Functional Theory (DFT) calculations show that interfacial charge transfer weakens the BH bonds and promotes deeper hydrolysis. Furthermore, Grand Canonical Monte Carlo (GCMC) simulations reveal the theoretical potential of these composites for cryogenic H₂ physisorption, with capacities reaching 21.5 ± 0.3 and 20.9 ± 0.2 wt%, respectively. This study establishes a versatile interfacial engineering paradigm for the development of high-performance hydrogen storage materials that simultaneously overcome kinetic and capacity limitations.