Hydrogen isotope separation and transport using 2D materials as membranes

Two-dimensional van der Waals (vdW) materials, such as transition-metal dichalcogenides (TMDCs), hexagonal boron nitride (hBN), and graphite, among others, feature interstitial voids—empty spaces between their layers. These voids, typically at least 3 Å in height, facilitate the transportation of small atoms or ions within confined conditions. The burgeoning interest in vdW materials in recent years stems from their potential applications as conduits for ion, atom, or isotope sieving technologies, as well as various energy-related applications.

Hydrogen, in both atomic and ionic forms, stands out as one of the smallest species capable of intercalating between TMDC layers while preserving the host material’s structure.

Furthermore, recent experiments conducted by Geim’s group in Manchester have shown that single-atom-thin membranes of mechanically exfoliated graphene and hBN are permeable to thermal protons (H+), yet much less so to deuterons (D+), resulting in a room-temperature separation factor of approximately 10, significantly higher than that achievable with conventional separation methods. Understanding the mechanism underlying this separation is crucial for optimizing smart 2D precision membranes.

Publications:

I. Eren, Y. An, A. B. Kuc, Hydrogen Transport Between Layers of Transition Metal-Dichalcogenides, Advanced Materials Interfaces 11, 2300798 (2024), DOI: https://doi.org/10.1002/admi.202300798.
W. Zhang, M. Makurat, X. Liu, X. Kang, X. Liu, Y. Li, T. J. F. Kock, C. Leist, C. Maheu, H. Sezen, L. Jiang, D. Calvani, A. Jiao, I. Eren, F. Buda, A. Kuc, T. Heine, H. Qi, X. Feng, J. P. Hofmann, U. Kaiser, L. Sun, Z. Liu, G. F. Schneider, Giant proton transmembrane transport through sulfophenylated graphene in a direct methanol fuel cell, pre-print https://arxiv.org/pdf/2308.16112.pdf
Y. An, A. F. Oliveira, T. Brumme, A. Kuc, T. Heine, Stone–Wales Defects Cause High Proton Permeability and Isotope Selectivity of Single-Layer Graphene, Adv. Mater. 32, 2002442 (2020), DOI: https://doi.org/10.1002/adma.202002442.
Y. An, A. Kuc, P. Petkov, M. Lozada-Hidalgo, T. Heine, On the Chemistry and Diffusion of Hydrogen in the Interstitial Space of Layered Crystals h-BN, MoS2, and Graphite, Small 15, 1901722 (2019), DOI:  https://doi.org/10.1002/smll.201901722