Ion transport in complex layered graphene-based membranes with tuneable interlayer spacing

Chi Cheng, Gengping Jiang, Chris Garvey, Yuanyuan Wang, George P. Simon, Jefferson Z. Liu, Dan Li

Research output: Contribution to journalArticleResearchpeer-review

129 Citations (Scopus)

Abstract

Investigation of the transport properties of ions confined in nanoporous carbon is generally difficult because of the stochastic nature and distribution of multiscale complex and imperfect pore structures within the bulk material. We demonstrate a combined approach of experiment and simulation to describe the structure of complex layered graphene-based membranes, which allows their use as a unique porous platform to gain unprecedented insights into nanoconfined transport phenomena across the entire sub–10-nm scales. By correlation of experimental results with simulation of concentration-driven ion diffusion through the cascading layered graphene structure with sub–10-nm tuneable interlayer spacing, we are able to construct a robust, representative structural model that allows the establishment of a quantitative relationship among the nanoconfined ion transport properties in relation to the complex nanoporous structure of the layered membrane. This correlation reveals the remarkable effect of the structural imperfections of the membranes on ion transport and particularly the scaling behaviors of both diffusive and electrokinetic ion transport in graphene-based cascading nanochannels as a function of channel size from 10 nm down to subnanometer. Our analysis shows that the range of ion transport effects previously observed in simple one-dimensional nanofluidic systems will translate themselves into bulk, complex nanoslit porous systems in a very different manner, and the complex cascading porous circuities can enable new transport phenomena that are unattainable in simple fluidic systems.
Original languageEnglish
Article numbere1501272
Number of pages9
JournalScience Advances
Volume2
Issue number2
DOIs
Publication statusPublished - 12 Feb 2016

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