A novel electrical double-layer ion transport carbon-based membrane with 3D porous structure: High permselectivity for dilute zinc ion separation
A novel electrical double-layer ion transport carbon-based membrane with 3D porous structure: High permselectivity for dilute zinc ion separation
复制标题
一种具有3D多孔结构的新型电双层离子传输碳基膜：用于稀锌离子分离的高渗透选择性
DOI：
10.1016/j.cej.2019.122413
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发表时间：
2020-01-15
影响因子：
15.1
通讯作者：
Tang, Keyong
中科院分区：
文献类型：
--
作者：
Gao, Fengfeng;Du, Xiao;Tang, Keyong
提出了一种新型的双电层离子传输碳基膜体系，用于稀锌离子的选择性分离。通过聚四氟乙烯（PTFE）膜对核壳结构的氮化石墨（g-C3 N4）@多壁碳纳米管（MWCNTs）分散液进行简单的压滤，制备了三维多孔碳基膜。为了实现Zn 2+的连续分离，设计并制备了一种智能电化学开关离子选择透过（ESIP）系统，该系统通过调节g-C3 N4 @MWCNTs膜的EDL上的正、负电荷密度与外加电场耦合实现。特别地，在这些材料中的EDL的快速充放电过程可以导致高速率和高通量的Zn 2+富集和耗尽。考察了电解槽电压、脉冲宽度和溶液初始浓度对Zn 2+通量和膜选择透过性的影响。结果表明，由于g-C3 N4 @MWCNTs复合膜的毛细管隧道效应，在最佳操作条件下，该体系对Zn 2+具有高通量（约10 g m（-2）h（-1））、高电流效率（38%）和良好的稳定性。这种具有三维多孔结构的碳基膜在实际废水处理中分离Zn 2+是一种很有前途的材料。
A novel electrical double-layer (EDL) ion transporting carbon-based membrane system was proposed for the selective separation of dilute zinc ion (Zn2+). The three-dimensional (3D) porous carbon-based membrane was fabricated by facile pressure filtering the core-shell graphite-nitride (g-C3N4)@multi-walled carbon nanotubes (MWCNTs) dispersed solution through a polytetrafluoroethylene (PTFE) membrane. In order to realize the continuous separation of Zn2+, a smart electrochemically switched ion permselective (ESIP) system was designed and made by modulating positive and negative charge density on EDL of g-C3N4@MWCNTs membrane coupling with an external electric field. In particular, the fast charge-discharge process of EDL in these materials could result in the high-rate and high-throughput of Zn2+ enrichment and depletion. The effects of cell voltage, pulse width and initial concentration on the flux of Zn2+ and the membrane permselectivity were investigated. It is discovered that the system had a high-flux (about 10 g m(-2) h(-1)) with a high current efficiency (38%) for the continuous separation of Zn2+ with good stability under optimal operating parameters owing to the capillary tunnel effect of the g-C3N4@MWCNTs composite membrane. Such an EDL carbon-based membrane with the 3D porous structure should be a promising material for the separation of Zn2+ in a practical wastewater treatment.