Ammoniating Covalent Organic Framework (COF) for High‐Performance and Selective Extraction of Toxic and Radioactive Uranium Ions

Abstract

An ideal porous adsorbent toward uranium with not only large adsorption capacity and high selectivity but also broad applicability even under rigorous conditions is highly desirable but still extremely scarce. In this work, a porous adsorbent, namely [NH 4 ] + [COF‐SO 3 − ], prepared by ammoniating a SO 3 H‐decorated covalent organic framework (COF) enables remarkable performance for uranium extraction. Relative to the pristine SO 3 H‐decorated COF (COF‐SO 3 H) with uranium adsorption capacity of 360 mg g −1 , the ammoniated counterpart of [NH 4 ] + [COF‐SO 3 − ] affords ultrahigh uranium uptake up to 851 mg g −1 , creating a 2.4‐fold enhancement. Such a value is the highest among all reported porous adsorbents for uranium. Most importantly, a large distribution coefficient, K d U , up to 9.8 × 10 6 mL g −1 is observed, implying extremely strong affinity toward uranium. Consequently, [NH 4 ] + [COF‐SO 3 − ] affords highly selective adsorption of uranium over a broad range of metal ions such as S U/Cs = 821, S U/Na = 277, and S U/Sr = 124, making it as effective uranium adsorbent from seawater, resulting in amazing uranium adsorption capacity of 17.8 mg g −1 . Moreover, its excellent chemostability also make it an effective uranium adsorbent even under rigorous conditions (pH = 1, 8, and 3 m acidity).

Regenerable and stable sp2 carbon-conjugated covalent organic frameworks for selective detection and extraction of uranium

“…It is worth noting that TFPT-BTAN-AO can achieve a saturation capacity of about 98% within 45 min. This is in sharp contrast to the long contact times required for other uranium sorbent materials, which typically range from hours to days 7,[47][48][49] . For comparison, POP-TB-AO took 85 min to reach 95% of its equilibrium adsorption capacity.…”

Alkynyl-Based sp 2 Carbon-Conjugated Covalent Organic Frameworks with Enhanced Uranium Extraction from Seawater by Photoinduced Multiple Effects

“…6 Owing to economics and versatility, chemical adsorption is considered to be the most promising technology for extracting uranium from seawater. 7,8 Recently, numerous porous materials have been developed for uranium extraction, [9][10][11][12][13] such as porous aromatic frameworks (PAFs), 14,15 metal-organic frameworks (MOFs), 6,16 and porous organic polymers (POPs); 17 all of them exhibit impressive uranium extraction performance. However, most adsorbents have poor stability in complex marine environments, leading to decomposition during long-term immersion in the ocean.…”

Orderly Porous Covalent Organic Frameworks-based Materials: Superior Adsorbents for Pollutants Removal from Aqueous Solutions

“…This composite also features better selectivity among 10 coexisting ions (Zn 2+ , Co 2+ , Ni 2+ , Mn 2+ , Sm 3+ , Gd 3+ , La 3+ , Nd 3+ , Sr 2+ , and Ce 3+ ) and excellent acid stability after the treatment of 8 M HNO 3 for 12 h. Recently, Xiong et al. 82 synthesized COF-SO 3 H with a combination of 2,4,6-triformylphloroglucinol and 1,2-dichlorobenzene, and then prepared [NH 4 ] + [COF-SO 3 − ] by immersing COF-SO 3 H in NH 3 ·H 2 O. The abundant –SO 3 − units in the pore wall could implement the coordination interaction toward U(VI).…”

“…The highest adsorption capacity for U(VI) has been reported to be 851 mg·g −1 for [NH 4 ] + [COF-SO 3 − ]. 82 To the authors’ knowledge, the most selective COF-based adsorbent for U(VI) reported to date is o -GS-COF. 81 The COF with the highest radiation stability reported is SCU-COF-1, which has been confirmed to maintain its physicochemical property even under irradiation of 600 kGy β-rays and 600 kGy γ-rays, 217 enough to meet the need of applications in radioactive waste management.…”

“…These advantages, together with the characteristics of predesigned structure, ordered porous structure, and adjustable physicochemical properties, make COFs promising next-generation materials with remarkable high sorption capacities for radioactive/toxic metal ions and organic contaminants. 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 …”