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Title: Ion selectivity of graphene nanopores

As population growth continues to outpace development of water infrastructure in many countries, desalination (the removal of salts from seawater) at high energy efficiency will likely become a vital source of fresh water. Due to its atomic thinness combined with its mechanical strength, porous graphene may be particularly well-suited for electrodialysis desalination, in which ions are removed under an electric field via ion-selective pores. Here, we show that single graphene nanopores preferentially permit the passage of K+ cations over Cl- anions with selectivity ratios of over 100 and conduct monovalent cations up to 5 times more rapidly than divalent cations. Furthermore, the observed K+/Cl- selectivity persists in pores even as large as about 20 nm in diameter, suggesting that high throughput, highly selective graphene electrodialysis membranes can be fabricated without the need for subnanometer control over pore size.
 [1] ;  [2] ;  [3]
  1. Harvard University, Cambridge, MA (United States). Dept. of Physics
  2. Harvard University, Cambridge, MA (United States). School of Engineering and Applied Sciences
  3. Harvard University, Cambridge, MA (United States). Dept. of Physics, School of Engineering and Applied Sciences
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 7; Journal ID: ISSN 2041-1723
Nature Publishing Group
Research Org:
Harvard Univ. Cambridge, MA (United States)
Sponsoring Org:
USDOE Office of Science (SC); ORISE/ORAU; National Institutes of Health
Country of Publication:
United States
36 MATERIALS SCIENCE single-layer graphene; water desalination; dna translocation; transport; membranes; nanochannels; channel