title: Sieving hydrogen isotopes through two-dimensional crystals.
abstract: One-atom-thick crystals are impermeable to atoms and molecules, but hydrogen ions (thermal protons) penetrate through them. We show that monolayers of graphene and boron nitride can be used to separate hydrogen ion isotopes. Using electrical measurements and mass spectrometry, we found that deuterons permeate through these crystals much slower than protons, resulting in a separation factor of ≈10 at room temperature. The isotope effect is attributed to a difference of ≈60 milli-electron volts between zero-point energies of incident protons and deuterons, which translates into the equivalent difference in the activation barriers posed by two-dimensional crystals. In addition to providing insight into the proton transport mechanism, the demonstrated approach offers a competitive and scalable way for hydrogen isotope enrichment.
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK. marcelo.lozadahidalgo@manchester.ac.uk geim@manchester.ac.uk.
authors.forename: M
authors.initials: M
authors.lastname: Lozada-Hidalgo
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: S
authors.initials: S
authors.lastname: Hu
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: O
authors.initials: O
authors.lastname: Marshall
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: A
authors.initials: A
authors.lastname: Mishchenko
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: A N
authors.initials: AN
authors.lastname: Grigorenko
authors.affiliation: School of Chemistry, University of Manchester, Manchester M13 9PL, UK.
authors.forename: R A W
authors.initials: RA
authors.lastname: Dryfe
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: B
authors.initials: B
authors.lastname: Radha
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: I V
authors.initials: IV
authors.lastname: Grigorieva
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK. marcelo.lozadahidalgo@manchester.ac.uk geim@manchester.ac.uk.
authors.forename: A K
authors.initials: AK
authors.lastname: Geim