Sustainable lithium extraction enabled by responsive metal- organic frameworks with ion- sieving adsorption effects

• 成果类型: Article
• 署名作者: Wu, Xu; Zhang, Huacheng; Zhang, Xinyu; Guan, Qian; Tang, Xiaocong; Wu, Hao; Feng, Mingbao; Wang, Huanting; Ou, Ranwen
• 署名单位: Xiamen University; Royal Melbourne Institute of Technology (RMIT); Tsinghua University; Monash University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13521
• DOI: 10.1073/pnas.2309852121
• 发表日期: 2024-02-06
• 关键词: adsorbent; water; capture

摘要

Metal- organic frameworks (MOFs) are superior ion adsorbents for selectively capturing toxic ions from water. Nevertheless, they have rarely been reported to have lithium selectivity over divalent cations due to the well - known flexibility of MOF framework and the similar physiochemical properties of Li+ and Mg2+. Herein, we report an ion- sieving adsorption approach to design sunlight- regenerable lithium adsorbents by subnanoporous MOFs for efficient lithium extraction. By integrating the ion- sieving agent of MOFs with light- responsive adsorption sites of polyspiropyran (PSP), the ion- sieving adsorption behaviors of PSP-MOFs with 6.0, 8.5, and 10.0 angstrom windows are inversely proportional to their pore size. The synthesized PSP- UiO-66 with a narrowest window size of 6.0 angstrom shows high LiCl adsorption capacity up to 10.17 mmol g-1 and good Li+/ Mg2+ selectivity of 5.8 to 29 in synthetic brines with Mg/Li ratio of 1 to 0.1. It could be quickly regenerated by sunlight irradiation in 6 min with excellent cycling performance of 99% after five cycles. This work sheds light on designing selective adsorbents using responsive subnanoporous materials for environmentally friendly and energy- efficient ion separation and purification.