Functional anchor implantation in zeolitic imidazolate frameworks for superhigh iodine and organic iodides adsorption
Qian Su, Zhan‐Yun Zhang, Fangyun Chen, Zilu Chen, Huancheng Hu
Abstract
Adsorption of iodine pollutants particularly molecular iodine and organic iodides, primarily methyl iodide (CH 3 I) and ethyl iodide (C 2 H 5 I), is of importance environmental issue but still maintains challenging. Herein, electron-rich functional anchor has been successfully implanted in both methyl and aldehyde group-containing zeolitic imidazolate frameworks ZIF-93 and ZIF-94 via condensation of aldehyde group with amine. Notably, the obtained Post-ZIF-93 and Post-ZIF-94 exhibited excellent static adsorption performances toward I 2 with 8.33 and 7.94 g/g, CH 3 I with 1.93 and 2.01 g/g, and C 2 H 5 I with 1.65 and 1.64 g/g at 75 °C, which are greatly enhanced comparing with their parents, being the highest static I 2 and organic iodides adsorption capacity among MOFs-based adsorbents under similar condition. Additionally, iodine and organic iodides adsorption kinetics models indicated that the diffusion of iodine and organic iodides molecule controlled their uptake behavior. I 2 and I 3 − motifs/I 3 − anion were observed in iodine/organic iodide-saturated samples, respectively. Density functional theory calculation uncovered that stronger affinities existed in iodine/organic iodides and the networks of Post-ZIF-93 / Post-ZIF-94 . This work not only breaks through the present static adsorption capacity of I 2 and organic iodides for MOFs-based materials, but also provides some instructive synthetic strategies in constructing novel adsorbents with outstanding iodine pollutants capture ability.