Proton and Li-Ion Permeation through Graphene with Eight-Atom-Ring Defects
Abstract
Defect-free graphene is impermeable to gases and liquids but highly permeable to thermal protons. Atomic-scale defects such as vacancies, grain boundaries and Stone-Wales defects are predicted to enhance graphene's proton permeability and may even allow small ions through, whereas larger species such as gas molecules should remain blocked. These expectations have so far remained untested in experiment. Here we show that atomically thin carbon films with a high density of atomic-scale defects continue blocking all molecular transport, but their proton permeability becomes ~1,000 times higher than that of defect-free graphene. Lithium ions can also permeate through such disordered graphene. The enhanced proton and ion permeability is attributed to a high density of 8-carbon-atom rings. The latter pose approximately twice lower energy barriers for incoming protons compared to the 6-atom rings of graphene and a relatively low barrier of ~0.6 eV for Li ions. Our findings suggest that disordered graphene could be of interest as membranes and protective barriers in various Li-ion and hydrogen technologies.
Cite
@article{arxiv.2005.09418,
title = {Proton and Li-Ion Permeation through Graphene with Eight-Atom-Ring Defects},
author = {Eoin Griffin and Lucas Mogg and Guang-Ping Hao and Gopinadhan Kalon and Cihan Bacaksiz and Guillermo Lopez-Polin and T. Y. Zhou and Victor Guarochico and Junhao Cai and Christof Neumann and Andreas Winter and Michael Mohn and Jong Hak Lee and Junhao Lin and Ute Kaiser and Irina V. Grigorieva and Kazu Suenaga and Barbaros Ozyilmaz and Hui-Min Cheng and Wencai Ren and Andrey Turchanin and Francois M. Peeters and Andre K. Geim and Marcelo Lozada-Hidalgo},
journal= {arXiv preprint arXiv:2005.09418},
year = {2020}
}