- Title
- Liquid-phase water isotope separation using graphene-oxide membranes
- Creator
- Ching, Karin; Baker, Andy; Tanaka, Ryoji; Zhao, Tingwen; Su, Zhen; Ruoff, Rodney S.; Zhao, Chuan; Chen, Xianjue
- Relation
- Carbon Vol. 186, Issue January 2022, p. 344-354
- Publisher Link
- http://dx.doi.org/10.1016/j.carbon.2021.10.009
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2021
- Description
- We report pressure-driven liquid-phase isotope separation (dead-end filtration) to enrich D and 18O in natural water using graphene oxide (G-O) and UV-reduced graphene oxide (UV-rG-O) membranes. The isotope diffusivity (molecular diffusion and adsorption separation) was found to be responsible for isotope separation. Adsorption separation is the dominant mechanism for improvements in D and 18O enrichment via increased G-O loading that leads to the increased number of adsorption sites (epoxy and hydroxyl groups on G-O), and higher degrees of reduction of G-O that result in the narrowing of the nanochannels which decreases the portion of water molecules experiencing molecular diffusion. The best performing membrane was “UV-rG-O” made by exposing a G-O membrane to 24 h UV irradiation from one side, showing enrichment of D of 0.5% for D/H and 18O of 0.08% for 18O/16O in a single-stage experiment, without contribution from the vapor pressure isotope effect. This work improves the understanding of the mechanisms for graphene-based membrane separation of D and 18O enriched water.
- Subject
- graphene oxide; membranes; water isotopes; filtration; isotope effect; diffusion
- Identifier
- http://hdl.handle.net/1959.13/1459879
- Identifier
- uon:45805
- Identifier
- ISSN:0008-6223
- Language
- eng
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