Phosphine-based covalent organic framework for highly efficient iodine capture

The efficient capture of nuclear waste such as radionuclide iodine has received more worldwide attention because of the effects of radiation on biological health. Adsorption is considered to be an efficient, low-cost, and environmentally friendly method for iodine removal. Recently, a new kind of phosphine-based covalent organic frameworks (P-COFs) with flexible and nonplanar structure have attracted great attention because of their high specific surface area and good thermal stability. The existence of electron-rich heteroatoms (P, N) as well as the large pi-conjugated network structure may be beneficial to the absorption of iodine. In this study, a biphenyl linked P-COF was synthesized for the capture of iodine. It shows a uniform microsphere structure with a diameter of about 1.2 mu m, a large BET surface area up to 1056 m(2) g(-1), and a high thermal stability (up to 500 degrees C). This PCOF exhibits rapid and exceptional iodine uptake in both volatile iodine and iodine/cyclohexane solution with adsorption capacities of 6.19 g g(-1) and 1.30 g g(-1), respectively, suggesting that P-COF may be a potential candidate for radioiodine capture from nuclear waste.

Automated summary

Efficient capture of nuclear waste, like radionuclide iodine, has drawn global attention due to health concerns. Phosphine-based covalent organic frameworks (P-COFs) show high specific surface area and thermal stability, making them promising for iodine adsorption. A synthesized biphenyl linked P-COF demonstrates exceptional iodine uptake, indicating potential for radioiodine capture from nuclear waste.