Three novel triazine-based materials with different O/S/N set of donor atoms: One-step preparation and comparison of their capability in selective separation of uranium

• Published in: Journal of hazardous materials 2015-12, Vol.300, p.368-377
• Main Authors: Bai, Chiyao, Zhang, Meicheng, Li, Bo, Tian, Yin, Zhang, Shuang, Zhao, Xiaosheng, Li, Yang, Wang, Lei, Ma, Lijian, Li, Shoujian
• Format: Article
• Language: English
• Subjects: Covalent triazine frameworks; Functional adsorbents; High N-concentration; Kinetics; Selective adsorption
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2015.07.020

[Display omitted] •Three novel functional covalent triazine-based frameworks are prepared.•Synthesis and functionalization of the products are accomplished in one step.•Various adsorbents can be prepared using cyanuric chloride as a core skeleton.•The products have high N concentration, regular structures, and high stabilities.•The products exhibit high sorption capacities and distinct selectivity for U (VI). Cyanuric chloride was chosen as a core skeleton which reacted with desired linker molecules, urea, thiourea and thiosemicarbazide, to prepare three novel functional covalent triazine-based frameworks, CCU (O-donor set), CCTU (S-donor set) and CCTS (S, N-donor set) respectively, designed for selective adsorption of U(VI). The products have high nitrogen concentration (>30wt%), regular structure, relatively high chemical and thermal stability. Adsorption behaviors of the products on U(VI) were examined by batch experiments. CCU and CCTU can extract U(VI) from simulated nuclear industrial effluent containing 12 co-existing cations with relatively high selectivity (54.4% and 54.2%, respectively). Especially, effects of donor atoms O/S on adsorption were investigated, and the outcomes indicate that the difference in coordinating ability between the donor atoms is weakened in large conjugated systems, and the related functional groups with originally very strong coordination abilities may not be the best choice for the application in selective adsorption of uranium and also other metals. The as-proposed approach can easily be expanded into design and preparation of new highly efficient adsorbents for selective separation and recovery of uranium through adjusting the structures, types and amounts of functional groups of adsorbents by choosing suitable linkers.