{"title":"Lithium complexing strategy based on host-guest recognition for efficient Mg2+/Li+ separation","authors":"Xiangmin Xu, Xiaowei Zhu, Jinchao Chen, Xingran Zhang, Zhiwei Wang, Fang Li","doi":"10.1016/j.watres.2025.123100","DOIUrl":null,"url":null,"abstract":"Ion selective membranes with precise Mg<sup>2+</sup>/Li<sup>+</sup> separation have attracted extensive interest in lithium extraction to circumvent the lithium supply shortage. However, realizing this target remains a significant challenge mainly due to a high concentration ratio of Mg<sup>2+</sup>/Li<sup>+</sup> as well as the relatively close ionic hydration radius and chemical. Herein, inspired by the host-guest recognition between alkali-metal ions and crown ether (CE), a novel approach was proposed to regulate the membrane internal structure by introducing CE to strengthen the complexation between Li<sup>+</sup> and CE. The CE modified membranes achieved the unique outcome of “Li<sup>+</sup> rejection-Mg<sup>2+</sup> permeation” deriving from enhanced solubility (<em>K<sub>S</sub></em>) and retarded diffusivity (<em>D<sub>S</sub></em>) of Li<sup>+</sup> compared to that of Mg<sup>2+</sup>. The Mg<sup>2+</sup>/Li<sup>+</sup> separation factors for MgSO<sub>4</sub>/Li<sub>2</sub>SO<sub>4</sub> and MgCl<sub>2</sub>/LiCl of modified membranes (<em>i.e.,</em> 20.1 and 17.7) are about 21.9 and 19.9 time higher than that of pristine membranes, respectively. The results from density function theory (DFT) indicated that the stronger host-guest interaction between CE and Li<sup>+</sup> combined them closely, thereby increasing solubility and reducing diffusivity of Li<sup>+</sup>. Our findings develop a new efficient membrane-based strategy enabling the production of high-purity lithium salts from simulated brine.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"76 1","pages":""},"PeriodicalIF":11.4000,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1016/j.watres.2025.123100","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Ion selective membranes with precise Mg2+/Li+ separation have attracted extensive interest in lithium extraction to circumvent the lithium supply shortage. However, realizing this target remains a significant challenge mainly due to a high concentration ratio of Mg2+/Li+ as well as the relatively close ionic hydration radius and chemical. Herein, inspired by the host-guest recognition between alkali-metal ions and crown ether (CE), a novel approach was proposed to regulate the membrane internal structure by introducing CE to strengthen the complexation between Li+ and CE. The CE modified membranes achieved the unique outcome of “Li+ rejection-Mg2+ permeation” deriving from enhanced solubility (KS) and retarded diffusivity (DS) of Li+ compared to that of Mg2+. The Mg2+/Li+ separation factors for MgSO4/Li2SO4 and MgCl2/LiCl of modified membranes (i.e., 20.1 and 17.7) are about 21.9 and 19.9 time higher than that of pristine membranes, respectively. The results from density function theory (DFT) indicated that the stronger host-guest interaction between CE and Li+ combined them closely, thereby increasing solubility and reducing diffusivity of Li+. Our findings develop a new efficient membrane-based strategy enabling the production of high-purity lithium salts from simulated brine.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.