Extrinsic cation selectivity of 2D membranes
From a systematic study of the concentration driven diffusion of positive and negative ions across porous 2D membranes of graphene and hexagonal boron nitride (h-BN), we prove their cation selectivity. Using the current–voltage characteristics of graphene and h-BN monolayers separating reservoirs of...
| Main Authors: | , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
American Chemical Society
2017
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| _version_ | 1797078259389693952 |
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| author | Walker, MI Ubych, K Saraswat, V Chalklen, EA Braeuninger-Weimer, P Caneva, S Weatherup, RS Hofmann, S Keyser, UF |
| author_facet | Walker, MI Ubych, K Saraswat, V Chalklen, EA Braeuninger-Weimer, P Caneva, S Weatherup, RS Hofmann, S Keyser, UF |
| author_sort | Walker, MI |
| collection | OXFORD |
| description | From a systematic study of the concentration driven diffusion of positive and negative ions across porous 2D membranes of graphene and hexagonal boron nitride (h-BN), we prove their cation selectivity. Using the current–voltage characteristics of graphene and h-BN monolayers separating reservoirs of different salt concentrations, we calculate the reversal potential as a measure of selectivity. We tune the Debye screening length by exchanging the salt concentrations and demonstrate that negative surface charge gives rise to cation selectivity. Surprisingly, h-BN and graphene membranes show similar characteristics, strongly suggesting a common origin of selectivity in aqueous solvents. For the first time, we demonstrate that the cation flux can be increased by using ozone to create additional pores in graphene while maintaining excellent selectivity. We discuss opportunities to exploit our scalable method to use 2D membranes for applications including osmotic power conversion. |
| first_indexed | 2024-03-07T00:29:32Z |
| format | Journal article |
| id | oxford-uuid:7f47c788-cd72-4425-8f33-46353fe8bdb7 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:29:32Z |
| publishDate | 2017 |
| publisher | American Chemical Society |
| record_format | dspace |
| spelling | oxford-uuid:7f47c788-cd72-4425-8f33-46353fe8bdb72022-03-26T21:16:07ZExtrinsic cation selectivity of 2D membranesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:7f47c788-cd72-4425-8f33-46353fe8bdb7EnglishSymplectic ElementsAmerican Chemical Society2017Walker, MIUbych, KSaraswat, VChalklen, EABraeuninger-Weimer, PCaneva, SWeatherup, RSHofmann, SKeyser, UFFrom a systematic study of the concentration driven diffusion of positive and negative ions across porous 2D membranes of graphene and hexagonal boron nitride (h-BN), we prove their cation selectivity. Using the current–voltage characteristics of graphene and h-BN monolayers separating reservoirs of different salt concentrations, we calculate the reversal potential as a measure of selectivity. We tune the Debye screening length by exchanging the salt concentrations and demonstrate that negative surface charge gives rise to cation selectivity. Surprisingly, h-BN and graphene membranes show similar characteristics, strongly suggesting a common origin of selectivity in aqueous solvents. For the first time, we demonstrate that the cation flux can be increased by using ozone to create additional pores in graphene while maintaining excellent selectivity. We discuss opportunities to exploit our scalable method to use 2D membranes for applications including osmotic power conversion. |
| spellingShingle | Walker, MI Ubych, K Saraswat, V Chalklen, EA Braeuninger-Weimer, P Caneva, S Weatherup, RS Hofmann, S Keyser, UF Extrinsic cation selectivity of 2D membranes |
| title | Extrinsic cation selectivity of 2D membranes |
| title_full | Extrinsic cation selectivity of 2D membranes |
| title_fullStr | Extrinsic cation selectivity of 2D membranes |
| title_full_unstemmed | Extrinsic cation selectivity of 2D membranes |
| title_short | Extrinsic cation selectivity of 2D membranes |
| title_sort | extrinsic cation selectivity of 2d membranes |
| work_keys_str_mv | AT walkermi extrinsiccationselectivityof2dmembranes AT ubychk extrinsiccationselectivityof2dmembranes AT saraswatv extrinsiccationselectivityof2dmembranes AT chalklenea extrinsiccationselectivityof2dmembranes AT braeuningerweimerp extrinsiccationselectivityof2dmembranes AT canevas extrinsiccationselectivityof2dmembranes AT weatheruprs extrinsiccationselectivityof2dmembranes AT hofmanns extrinsiccationselectivityof2dmembranes AT keyseruf extrinsiccationselectivityof2dmembranes |