Highly Porous Self-Supporting Graphene Oxide-Based Membranes for the Selective Separation of Lithium Ions

Abstract

Facilitating the accurate recognition of lithium ions (Li + ) by filtration membranes is of great significance for the efficient and selective separation of Li + from saline lake brine and seawater. Herein, a highly porous self-supporting graphene oxidebased (GCS) membrane modified by single-walled carbon nanotubes (SWCNTs) and 4-aminobenzo-12-crown-4 (AB12C4) was fabricated via a facile and versatile vacuum filtration method. The highly porous structure constructed with polystyrene microspheres as a self-sacrificial template could provide a larger contact area at the solid−liquid interface. Moreover, the addition of electric SWCNTs endows the GCS membrane with a tunable adsorption behavior by an external electric field. Meanwhile, the decoration of AB12C4 on the multilayered GCS membrane realizes a specific recognition of Li + with an excellent adsorption capacity of 37.0 mg g −1 , exhibiting considerably high separation factors against Na + (18.97), K + (26.19), Mg 2+ (16.67), and Ca 2+ (19.64). According to the density functional theory calculations, the adsorption of GCS membrane for Li + is more thermodynamically favorable than that of the contrast ions. This work demonstrates an effective approach with the convenient vacuum filtration technology for the selective adsorption of Li + , which could alleviate the shortage of lithium resources.

Ultrasound assisted efficient separation of lithium from brine with a composite polyether sulfone-ionic liquid membrane

“…The pristine polyamide thin-film composite (TFC) membrane modified with DABIL exhibited the highest lithium ion selectivity of 26.49 among the membranes studied. 49 The MXene nanosheets on hydrophilic PTFE membrane exhibited a separating factor over 6 for Li + /Co 2+ separation. 57 The dibenzo-14-crown-4 ether-based polyimide (poly(DAB14C4-6FDA)) exhibited good selectivity for lithium ions over sodium and potassium ions.…”

Dehydration induced selective ion trapping by topology constrained atomically thin graphene-crown membranes

“…The novel advancement in experimental technologies has promoted the successful synthesis of these nano-structures achieved by vacancy oxidation 35 and oxygen plasma-etching methods. 36 Cheng et al , 37 in their recent experimental studies, fabricated a highly porous self-supporting graphene oxide based (GCS) membrane for efficient and selective separation of Li + from saline lake brine and seawater. This membrane contains 4-aminobenzo-12-crown-4 (AB12C4) externally grafted to graphene oxide.…”