A Lamellar MXene (Ti₃C₂T_x)/PSS Composite Membrane for Fast and Selective Lithium‐Ion Separation

Abstract

A two‐dimensional (2D) laminar membrane with Li+ selective transport channels is obtained by stacking MXene nanosheets with the introduction of poly(sodium 4‐styrene sulfonate) (PSS) with active sulfonate sites, which exhibits excellent Li+ selectivity from ionic mixture solutions of Na+, K+, and Mg2+. The Li+ permeation rate through the MXene@PSS composite membrane is as high as 0.08 mol m−2 h−1, while the Li+/Mg2+, Li+/Na+, and Li+/K+ selectivities are 28, 15.5, and 12.7, respectively. Combining the simulation and experimental results, we further confirm that the highly selective rapid transport of partially dehydrated Li+ within subnanochannels can be attributed to the precisely controlled interlayer spacing and the relatively weaker ion‐terminal (−SO3−) interaction. This study deepens the understanding of ion‐selective permeation in confined channels and provides a general membrane design concept.

Zinc Anode for Mild Aqueous Zinc-Ion Batteries: Challenges, Strategies, and Perspectives

“…As a buffer layer that separates the active Zn from the bulk electrolyte, especially electronic insulation properties, the concentration field can generally be mechanically adjusted by constructing the confined channel, such as porous or layered structure. According to the size-selective exclusion effect, to enable the stable migration of Zn 2+ ions and block other larger-sized molecules and ions, the confined channel structure should be well organized and have an appropriate channel size [ 53 ]. For instance, the Nafion–Zn-X modified layer formed by the complexation of Nafion and Zn-X zeolite (Fig.…”

Selective Ion Transport in Two-Dimensional Ti3C2Tx Nanochannel Decorated by Crown Ether

“…28 The Ti 3 C 2 T x @ poly(sodium 4-styrene sulfonate) composite membranes exhibited Li + permeabilities up to 0.08 mol•m −2 •h −1 , with Li + /Mg 2+ , Li + /Na + , and Li + /K + selectivities of 28, 15.5, and 12.7, respectively. 29 Although 2D lamellar membranes have shown promising potential for use in ion sieving, their selectivities and permeabilities have not yet reached the expected levels and require further optimization. Biological ion channels exhibit remarkable ion separation capabilities, and they provide valuable inspiration for improving the ion selectivities of 2D laminar membranes.…”

“…Nonswelling Al 13 -intercalated Ti 3 C 2 T x membranes have demonstrated excellent desalination performance, achieving high NaCl rejection rates (99%) with fast water fluxes (0.30 L m –2 ·h –1 ·bar –1 ) . The Ti 3 C 2 T x @poly­(sodium 4-styrene sulfonate) composite membranes exhibited Li + permeabilities up to 0.08 mol·m –2 ·h –1 , with Li + /Mg 2+ , Li + /Na + , and Li + /K + selectivities of 28, 15.5, and 12.7, respectively . Although 2D lamellar membranes have shown promising potential for use in ion sieving, their selectivities and permeabilities have not yet reached the expected levels and require further optimization.…”

Efficient solar energy conversion via bionic sunlight-driven ion transport boosted by synergistic photo-electric/thermal effects

“…[8][9][10] Compared with 1D nanochannels, except for the advantages in the scalability of fabrication, it is also possible to accurately adjust both the chemical and the physical characteristics of 2D lamellar nanofluidic systems because efficient chemical modification of the nanosheets could be achieved before building up the nanoarchitectures. 3,[11][12][13][14] For instance, modifying the surface charge properties, wetting behavior, and channel sizes of 2D nanochannels have been reported to improve ion selectivity. [15][16][17] Although the 2D lamellar membrane is drawing wide attention and is considered the next-generation membrane, in most previous works in the literature, the nanosheet has not merely been treated as a ''solid brick'' in the spatial structure.…”