A Double-Walled Thorium-Based Metal–Organic Framework as a Promising Dual-Function Absorbent for Efficiently Capturing Iodine and Dyes

• Published in: Crystal growth & design 2019-10, Vol.19 (10), p.5686-5695
• Main Authors: Zhang, Na, Sun, Li-Xian, Xing, Yong-Heng, Bai, Feng-Ying
• Format: Article
• Language: English
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/acs.cgd.9b00671

We prepared a rare thorium metal–organic framework (MOF) (Th-TATAB) with a double-walled tetrahedral cage structure and giant unit cell volume of 43 513 Å3, which is the largest of all reported thorium-based MOFs to our knowledge. The unique structural character allows the thorium-based MOF to exhibit exceptional adsorption properties toward I2 and dyes with different charges. The experimental results show that in cyclohexane solution the absorption ability of Th-TATAB toward I2 can reach about 750 mg/g, and especially the removal efficiency in cyclohexane solution (0.01 mol/L) can reach 90% in 3 h, which far exceeded that of reported [Zn2(tptc)-(apy)2‑x (H2O) x ]·H2O (80%, 48 h) and MIL-101-NH2 (90%, 30 h). Furthermore, the simultaneous removal of molecules with different charges is very challenging, while Th-TATAB displays excellent adsorption properties for anionic, neutral, and cationic dyes individually and simultaneously from aqueous solution. The exploration of the adsorption performance of MOF Th-TATAB for iodine in cyclohexane solution and dye contaminants in aqueous solution is of great significance for environmental aspects, which provides a new strategy for opening up the potential applications of thorium-based MOFs and understanding actinides chemistry.