Abstract
AbstractDespite the potential environmental benefits, the use of membranes for extracting, reclaiming, and purifying alkali metals from aqueous feedstocks remains challenging due to low inter‐cation selectivity. Two‐dimensional materials equipped with nanoscale pores have revealed intriguing performance in ion separation, but their practical implementation is bottlenecked by the perforation procedures. This work presents electrodialysis experiments with intrinsically porous carbon nanomembranes (CNMs) that are featured by a high areal density of sub‐nanometer channels. The free‐standing membranes prepared from pyrene are shown to have great mechanical strength and a narrow pore size distribution enabling selective passage of metal ions. CNMs can sieve hydrated cations following the order K+ > Na+ > Li+ > Ca2+ > Mg2+, while the K+/Mg2+, Na+/Mg2+, Li+/Mg2+ selectivity amounts to 220, 86, and 13 respectively. It is found that the ion transport selectivity is attributed to the combined effect of the small pore dimensions and electrostatic exclusion induced by surface charges. It has been also observed that the membrane thickness in the range from 3 to 6.5 nm has little impact on the ion transport which suggests interesting implications for ion batteries and other energy conversion systems.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
