DFT Analysis on the Separation Mechanism of Hydrogen Isotopes Through Graphene and Boron Nitride 2D Sheets

As an existing method, proton-overdeuteron (H+-over-D+) can permeate through graphene by chemical pumping with a high selectivity quantum sieving effect at room temperature. The value from the controversially discussed mechanistic model of the penetration process by the chemisorption of local hydrogenation in the elementary unit of two-dimensional monolayer membrane has been a deviation from the obtained experimental separation coefficient of 10. Quantum sieving kinetic isotope effects must be reconsidered in the proposed models with a smaller scale and more detailed structure. The formed composite structures in the elementary unit in the penetration process based on the charge density, density of states and energy barrier calculations, and configurations of H3O+-g-Pt and H3O+-h-BN-Pt proved that the "hole" permeation mechanism had been consistent with the published separation coefficient of hydrogen isotopes and revealed that kinetic isotope effects had depended on the intense interaction between hydrogen isotopes and the key elementary unit of the two-dimensional materials.