Heterogeneous sub-continuum ionic transport in statistically isolated graphene nanopores
Name
Heterogeneous ion transport - Jain et al accepted manuscript.docx
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2.89 MB
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Checksum (MD5)
c1c57740b1cfa8ece452869c2a19d941
Author(s)
Idrobo, Juan-Carlos
Jain, Tarun Kumar
Rasera, Benjamin
Guerrero, Ricardo Jose
Boutilier, Michael Stephen Hatcher
O'Hern, Sean C
Karnik, Rohit
Date Issued
October 2015
Journal
Nature Nanotechnology
Publisher
Nature Publishing Group
Citation
Jain, Tarun, Benjamin C. Rasera, Ricardo Jose S. Guerrero, Michael S. H. Boutilier, Sean C. O’Hern, Juan-Carlos Idrobo, and Rohit Karnik. “Heterogeneous Sub-Continuum Ionic Transport in Statistically Isolated Graphene Nanopores.” Nature Nanotechnology 10, no. 12 (October 5, 2015): 1053–1057.
Version
Author's final manuscript
Abstract
Graphene and other two-dimensional materials offer a new class of ultrathin membranes that can have atomically defined nanopores with diameters approaching those of hydrated ions1, 2, 3, 4, 5, 6, 7. These nanopores have the smallest possible pore volumes of any ion channel, which, due to ionic dehydration8 and electrokinetic effects9, places them in a novel transport regime and allows membranes to be created that combine selective ionic transport10 with ultimate permeance11, 12, 13 and could lead to separations14, 15 and sensing16 applications. However, experimental characterization and understanding of sub-continuum ionic transport in nanopores below 2 nm is limited17, 18. Here we show that isolated sub-2 nm pores in graphene exhibit, in contrast to larger pores, diverse transport behaviours consistent with ion transport over a free-energy barrier arising from ion dehydration and electrostatic interactions. Current–voltage measurements reveal that the conductance of graphene nanopores spans three orders of magnitude8 and that they display distinct linear, voltage-activated or rectified current–voltage characteristics and different cation-selectivity profiles. In rare cases, rapid, voltage-dependent stochastic switching is observed, consistent with the presence of a dissociable group in the pore vicinity19. A modified Nernst–Planck model incorporating ion hydration and electrostatic effects quantitatively matches the observed behaviours.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
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DOI of Published Version
https://doi.org/10.1038/nnano.2015.222
