Functional anchor implantation in zeolitic imidazolate frameworks for superhigh iodine and organic iodides adsorption

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. • Post-ZIF-93 and Post-ZIF-94 exhibits excellent iodine vapor adsorption performance. • Post-ZIF-93 and Post-ZIF-94 shows superhigh organic iodides adsorption capacity. • The iodine and organic iodides adsorption mechanism are clearly uncovered.