The capture of radioactive I 2 vapor from nuclear waste under industrial operating conditions remains a challenging task, as the practical industrial conditions of high temperature (≥150 °C) and low I 2 concentration (∼150 ppmv) are unfavorable for I 2 adsorption. We report a novel guanidinium-based covalent organic framework (COF), termed TGDM, which can efficiently capture I 2 under industrial operating conditions. At 150 °C and 150 ppmv I 2 , TGDM exhibits an I 2 uptake of ∼30 wt %, which is significantly higher than that of the industrial silver-based adsorbents such as Ag@MOR (17 wt %) currently used in the nuclear fuel reprocessing industry. Characterization and theoretical calculations indicate that among the multiple types of adsorption sites in TGDM, only ionic sites can bond to I 2 through strong Coulomb interactions under harsh conditions. The abundant ionic groups of TGDM account for its superior I 2 capture performance compared to various benchmark adsorbents. In addition, TGDM exhibits exceptionally high chemical and thermal stabilities that fully meet the requirements of practical radioactive I 2 capture (high-temperature, humid, and acidic environment) and differentiate it from other ionic COFs. Furthermore, TGDM has excellent recyclability and low cost, which are unavailable for the current industrial silver-based adsorbents. These advantages make TGDM a promising candidate for capturing I 2 vapor during nuclear fuel reprocessing. This strategy of incorporating chemically stable ionic guanidine moieties in COF would stimulate the development of new adsorbents for I 2 capture and related applications.

Herein, we report a strategy to construct highly efficient perfluorooctanoic acid (PFOA) adsorbents by installing synergistic electrostatic/hydrophobic sites onto porous organic polymers (POPs). The constructed model material of PAF-1-NDMB (NDMB = N,N-dimethyl-butylamine) demonstrates an exceptionally high PFOA uptake capacity over 2000 mg g−1, which is 14.8 times enhancement compared with its parent material of PAF-1. And it is 32.0 and 24.1 times higher than benchmark materials of DFB-CDP (β-cyclodextrin (β-CD)-based polymer network) and activated carbon under the same conditions. Furthermore, PAF-1-NDMB exhibits the highest k2 value of 24,000 g mg−1 h−1 among all reported PFOA sorbents. And it can remove 99.99% PFOA from 1000 ppb to <70 ppt within 2 min, which is lower than the advisory level of Environmental Protection Agency of United States. This work thus not only provides a generic approach for constructing PFOA adsorbents, but also develops POPs as a platform for PFOA capture.

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Ammonia (NH 3 ) is one of the most important industrial feedstocks in the fields of fertilizers, drugs, explosives, ordnance, commercial cleanings, and so on. However, the features of ammonia such as high toxicity and corrosivity, and difficulty in handling would inevitably increase the risk of environmental damage and the deterioration of natural/public lands. Although sorts of solid adsorbents such as metal oxides, zeolites, organic polymers, activated carbons, and metal organic frameworks have been applied in NH 3 capture, they still show low uptake capacity, low affinities, and instability. Herein, we developed the first case of a highly stable sulfuric acid covalent organic framework (COF), namely TpBD-(SO 3 H) 2 , as NH 3 capturer, in which sulfonic acid sites can strongly interact with NH 3 molecules, and enhance the performance of NH 3 sorption. As a result, TpBD-(SO 3 H) 2 shows high chemical stability under strong acid and water conditions, an important merit for the potential application in harsh environment. And it also exhibits high ammonia capacity of 11.5 mmol•g −1 at 298 K and 1.0 bar, making it one of the best in all chemically stable NH 3 adsorbents up to date. This work thus develops sulfuric acid COF materials as a new platform for ammonia capture and storage.

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