Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, China.
School for Radiological and Interdisciplinary Sciences (RAD-X) and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University , Suzhou 215123, China.
ACS Appl Mater Interfaces. 2017 Feb 1;9(4):3774-3784. doi: 10.1021/acsami.6b15642. Epub 2017 Jan 20.
A preorganized tetradentate phenanthrolineamide (DAPhen) ligand with hard and soft donors combined in the same molecule has been found to possess high extraction ability toward actinides over lanthanides from acidic aqueous solution in our previous work. Herein we grafted phenanthrolineamide groups onto a large-pore three-dimensional cubic silica support by the reaction of DAPhen siloxane with KIT-6 substrate to prepare a novel uranium-selective sorbent, KIT-6-DAPhen. The as-synthesized sorbent was well-characterized by scanning electron microscopy, high-resolution transmission electron microscopy, N adsorption/desorption, X-ray diffraction, FT-IR, C cross-polarization magic-angle spinning NMR, and TGA techniques, which confirmed the consummation of the functionalization. Subsequently, the effects of contact time, solution pH, initial U(VI) concentration, and the presence of competing metal ions on the U(VI) sorption onto KIT-6-DAPhen sorbent were investigated in detail. It was found that KIT-6-DAPhen showed largely enhanced sorption capacity and excellent selectivity toward U(VI). The maximum sorption capacity of KIT-6-DAPhen at pH 5.0 reaches 328 mg of U/g of sorbent, which is superior to most of functionalized mesoporous silica materials. Density functional theory coupled with quasi-relativistic small-core pseudopotentials was used to explore the sorption interaction between U(VI) and KIT-6-DAPhen, which gives a sorption reaction of KIT-6-DAPhen + [UO(HO)] + NO ⇄ [UO(KIT-6-DAPhen)(NO)] + 5HO. The findings of the present work provide new clues for developing new actinide sorbents by combining new ligands with various mesoporous matrixes.
在我们之前的工作中发现，一种预先组织的四齿菲咯啉酰胺（DAPhen）配体，其硬和软供体结合在同一分子中，具有从酸性水溶液中高选择性萃取锕系元素而不是镧系元素的能力。在此，我们通过 DAPhen 硅氧烷与 KIT-6 基底的反应，将菲咯啉酰胺基团嫁接到大孔三维立方二氧化硅载体上，制备了一种新型的铀选择性吸附剂 KIT-6-DAPhen。通过扫描电子显微镜、高分辨率透射电子显微镜、N 吸附/解吸、X 射线衍射、FT-IR、C 交叉极化魔角旋转 NMR 和热重分析技术对合成的吸附剂进行了很好的表征，证实了功能化的完成。随后，详细研究了接触时间、溶液 pH 值、初始 U(VI)浓度和共存金属离子对 KIT-6-DAPhen 吸附剂吸附 U(VI)的影响。结果表明，KIT-6-DAPhen 对 U(VI)表现出很大的增强吸附能力和优异的选择性。在 pH 值为 5.0 时，KIT-6-DAPhen 的最大吸附容量达到 328mgU/g 吸附剂，优于大多数功能化介孔硅材料。密度泛函理论与准相对论小核赝势相结合，用于研究 U(VI)与 KIT-6-DAPhen 之间的吸附相互作用，得到 KIT-6-DAPhen + [UO(HO)] + NO ⇄ [UO(KIT-6-DAPhen)(NO)] + 5HO 的吸附反应。本工作的研究结果为通过将新型配体与各种介孔基质结合开发新型锕系元素吸附剂提供了新的线索。
