Adsorption Behavior of Iodine by Novel Covalent Organic Polymers Constructed Through Heterostructural Mixed Linkers

The efficient capture and storage radioactive iodine (129I or 131I) formed during the extensive use of nuclear energy is of paramount importance. Therefore, it is a great deal to design and empolder new adsorbents for effectively disposing of iodine from nuclear waste. In this work, we presented a novel covalent organic polymer (JLUE-COP-3) constructed through heterostructural mixed linkers with perforated porousness, plenty of π-conjugated phenyl rings and functional –CO–NH– and –SO3H groups to iodine adsorption process. After fully characterizing the morphology and structure, the adsorption behavior of iodine by the resultant polymers were explored in detail. The external adsorption behavior was determined to obey the pseudo-second order kinetic model according to the kinetic analysis. The maximum liquid adsorption capacity was obtained to reach 153.85 mg/g at 298 K, which was evaluated by the Langmuir isotherm model. In addition, the negative attributes of ΔG° as well as the positive attributes of ΔH° and ΔS° at three temperatures indicated the nature of the iodine adsorption over JLUE-COP-3 was spontaneous and endothermic. The current study could look forward to making great contributions to the facile fabrication of late-model three-component POP materials and their applications in treatment of nuclear waste