Metal–organic frameworks (MOFs) are a class of promising sorbents for effective sequestration of radioactive 99 TcO 4 – anions. However, their poor stability and slow sorption kinetics in the industrial condition pose a great challenge. Herein, we demonstrate an optimizing strategy via in situ polymerization of ionic liquids (ILs) encapsulated in the pores of MOFs, forming polyILs@MOFs composites with greatly enhanced TcO 4 – sequestration compared with the pristine MOFs. Notably, the cross-linked polymerization of ILs facilitates the formation of both the inside ionic filler as the active sites and outside coating as the protective layers of MOFs, which is significantly beneficial to obtain the optimized sorption materials of exceptional stability under extreme conditions (e.g., in 6 M HNO 3 ). The final optimized composite shows fast sorption kinetics (<30 s), good regeneration (>30 cycles), and superior uptake performance for TcO 4 – in highly acidic conditions and simulated recycle stream. This strategy opens up a new opportunity to construct the highly stable MOF-based composites and extend their applicability in different fields.

Rational design of anion-exchange materials for selective elimination of radioactive anionic contaminants poses a great challenge. Rather than relying on a size-compatible effect, combination of nano-sieve pore, hydrophobic cationic cavity,...

Sequestration of 99TcO4− from acidic or alkaline nuclear waste is highly desirable and necessary for purpose of energy sustainability and environment safety. However, it remains currently an unmet challenge given...

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Nuclear industry spent fuel reprocessing and some radioactive contamination sites often involve high acidity and salinity environments. Currently developed and reported sorbents in 99TcO4– sequestration from the nuclear waste are unstable and show low adsorption efficiency in harsh conditions. To address this issue, we developed a post‐synthetic modification strategy by grafting imidazole‐based ionic liquids (ILs) onto the backbone of covalent organic framework (COF) via vinyl polymerization. The resultant COF‐polyILs sorbent exhibits fast adsorption kinetics (< 5 min) and good sorption capacity (388 mg g–1) for ReO4− (a nonradioactive surrogate of 99TcO4−). Outstandingly, COF‐polyILs composite shows superior ReO4− removal even under highly acidic conditions and in the presence of excess competing ions of Hanford low‐level radioactive waste stream, benefiting from the stable covalent bonds between the COF and polyILs, mass of imidazole rings, and hydrophobic pores in COF.