Shearing Liquid-Crystalline MXene into Lamellar Membranes with Super-Aligned Nanochannels for Ion Sieving
- authored by
- Lingzhi Huang, Haoyu Wu, Li Ding, Jürgen Caro, Haihui Wang
- Abstract
Ion-selective membranes are crucial in various chemical and physiological processes. Numerous studies have demonstrated progress in separating monovalent/multivalent ions, but efficient monovalent/monovalent ion sieving remains a great challenge due to their same valence and similar radii. Here, this work reports a two-dimensional (2D) MXene membrane with super-aligned slit-shaped nanochannels with ultrahigh monovalent ion selectivity. The MXene membrane is prepared by applying shear forces to a liquid-crystalline (LC) MXene dispersion, which is conducive to the highly-ordered stacking of the MXene nanosheets. The obtained LC MXene membrane (LCMM) exhibits ultrahigh selectivities toward Li+/Na+, Li+/K+, and Li+/Rb+ separation (≈45, ≈49, and ≈59), combined with a fast Li+ transport with a permeation rate of ≈0.35 mol m−2 h−1, outperforming the state-of-the-art membranes. Theoretical calculations indicate that in MXene nanochannels, the hydrated Li+ with a tetrahedral shape has the smallest diameter among the monovalent ions, contributing to the highest mobility. Besides, the weakest interaction is found between hydrated Li+ and MXene channels which also contributes to the ultrafast permeation of Li+ through the super-aligned MXene channels. This work demonstrates the capability of MXene membranes in monovalent ion separation, which also provides a facile and general strategy to fabricate lamellar membranes in a large scale.
- Organisation(s)
-
Institute of Physical Chemistry and Electrochemistry
- External Organisation(s)
-
Tsinghua University
- Type
- Article
- Journal
- Angewandte Chemie - International Edition
- Volume
- 63
- ISSN
- 1433-7851
- Publication date
- 31.01.2024
- Publication status
- Published
- Peer reviewed
- Yes
- ASJC Scopus subject areas
- Catalysis, General Chemistry
- Electronic version(s)
-
https://doi.org/10.1002/anie.202314638 (Access:
Open)