Work

Gas Permeability and Selectivity of a Porous WS 2 Monolayer

Year: 2021

Type: article

Abstract: Atomically thin porous membranes display high selectivity for gas transport and separation. To create such systems, defect engineering of two-dimensional (2D) materials, e.g., via ion irradiation, provides an efficient route. Here, first-principles calculations are used to study the permeability of He, H 2, N 2, CO 2, and CH 4 molecules through WS 2 monolayers containing vacancy-type defects. We found that (i) for most pores, regardless of the pore size, H 2 exhibits large permeability (≃10 5 GPU), (ii) dissociation of H 2 molecules and edge saturation occur when they approach the angstrom-size pores, (iii) the 1W6S pore (one W and six S atoms are removed from a WS 2 monolayer) can separate H 2 and N 2 gases with high selectivity, and (iv) the 2W6S pore exhibits exceptionally high selectivity for separation of H 2 /CO 2 (≃10 13 ) and H 2 /CH 4 (≃10 9 ). Our study advances the understanding of the mechanisms behind gas permeability and selectivity through sub-nanometer pores in WS 2 and potentially other inorganic 2D materials.

Source: The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.1c06894

Authors: Nasim Hassani, Mahdi Ghorbani-Asl, Boya Radha, Marija Drndić, Arkady V. Krasheninnikov, Mehdi Neek-Amal