Suebphanpho Jitti, Jearanaiwiwat Pacharapon, Chainok Kittipong, Boonmak Jaursup
Materials Chemistry Research Center, Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
Thammasat University Research Unit in Multifunctional Crystalline Materials and Applications (TU-MCMA), Faculty of Science and Technology, Thammasat University, Pathum Thani, 12121, Thailand.
Chem Asian J. 2025 Jun;20(11):e202401532. doi: 10.1002/asia.202401532. Epub 2025 Apr 14.
The efficient removal of radioiodine from an aqueous solution is crucial for the sustainable advancement of nuclear energy and environmental conservation. In this work, two π-conjugated nonporous coordination polymers, namely, {[Co(bqdc)(dpe)(HO)]·HO} (Co-CP) and [Zn(bqdc)(dpe)] (Zn-CP) (bqdc = 2,2'-biquinoline-4,4'-dicarboxylate and dpe = 1,2-di(4-pyridyl)ethylene) were successfully synthesized and characterized. Single crystal X-ray analysis demonstrated that Co-CP and Zn-CP have different crystal structures. Co-CP displays the 1D chain via bidentate and monodentate coordination modes of bqdc and dpe, respectively, whereas Zn-CP presents a threefold interpenetrated 3D framework through bridging bidentated ligands. Both CPs exhibit a nonporous nature with high π-electron richness in the structural framework. Both compounds can adsorb iodine in vapor and solution phases with high adsorption capacity. The iodine adsorption capacities in the vapor phase at 70 °C are 3.54 and 1.57 g/g for Co-CP and Zn-CP, respectively. In addition, Co-CP and Zn-CP exhibit effective iodine adsorption in aqueous solutions with capacities of 2315.86 and 2032.97 mg/g, respectively. The adsorption kinetics, adsorption isotherms, competing anion adsorption, and iodine adsorption in real water samples were studied. The iodine adsorption mechanism is due to electron transfer from the effective sorption sites of CPs to iodine, forming the charge transfer complex, which was confirmed by FTIR, PXRD, EDX, and XPS techniques. They can also be reused to capture iodine in an aqueous solution with the ability to retain a high level of effectiveness.
从水溶液中高效去除放射性碘对于核能的可持续发展和环境保护至关重要。在这项工作中，成功合成并表征了两种π共轭无孔配位聚合物，即{[Co(bqdc)(dpe)(HO)]·HO}（Co-CP）和[Zn(bqdc)(dpe)]（Zn-CP）（bqdc = 2,2'-联喹啉-4,4'-二羧酸酯，dpe = 1,2-二(4-吡啶基)乙烯）。单晶X射线分析表明Co-CP和Zn-CP具有不同的晶体结构。Co-CP分别通过bqdc和dpe的双齿和单齿配位模式呈现一维链状结构，而Zn-CP通过桥连双齿配体呈现三重互穿的三维框架结构。两种配位聚合物在结构框架中均表现出无孔性质且具有高π电子丰富度。两种化合物在气相和溶液相中都能以高吸附容量吸附碘。在70°C下，Co-CP和Zn-CP在气相中的碘吸附容量分别为3.54和1.57 g/g。此外，Co-CP和Zn-CP在水溶液中表现出有效的碘吸附，容量分别为2315.86和2032.97 mg/g。研究了吸附动力学、吸附等温线、竞争阴离子吸附以及实际水样中的碘吸附情况。碘吸附机制是由于配位聚合物的有效吸附位点向碘发生电子转移，形成电荷转移络合物，这通过傅里叶变换红外光谱（FTIR）、粉末X射线衍射（PXRD）、能量色散X射线光谱（EDX）和X射线光电子能谱（XPS）技术得到证实。它们还可以重复用于捕获水溶液中的碘，并保持高水平的有效性。
