Rational Synthesis of Crystalline Covalent Triazine Framework with Methylthio Pendant Arms for Efficient Mercury(Ⅱ)Adsorption

用于高效吸附汞(Ⅱ)的含有甲基硫侧链的共价三嗪框架

The interest in curtailing environmental pollution issues through physical separation processes has inspired an extensive search for novel nanoporous materials with exceptional adsorption capabilities.Covalent triazine frameworks(CTFs),emerged as a class of crystalline covalent organic frameworks(COFs),have been widely examined for various separation applications,owing to their large porosity,high stability,and rich nitrogen(N)doping.The development of CTFs for efficient adsorption of mercury(Ⅱ)(Hg^(2+))is of great importance for the field,whereas it is rarely attempted,on account of limited synthetic strategies and unknown structural-property relations of conventional CTFs derived from ionothermal approaches.Herein,we report rational synthesis of a crystalline CTF with methylthio pendant arms for efficient removal of Hg^(2+)with an exceptional capacity of 751 mg·g^(-1),ranking at the top among previously-reported adsorbents.This work may open up new possibility in the synthesis of COFs for various separations.

通过物理分离过程可缓解环境污染问题,这一策略激发了人们对具有优异吸附能力的新型纳米多孔材料的研究兴趣.共价三嗪框架(CTFs)作为共价有机框架(COFs)材料的一种,具有大孔隙度、高稳定性和丰富的氮原子掺杂等特性,在吸附分离中被广泛研究和应用.开发用于高效吸附汞(Ⅱ)(Hg^(2+))的CTFs材料在该领域具有重要的意义,但是由于合成策略有限以及基于离子热法衍生的传统CTFs的结构-性能之间的关系尚不明确,因此很少尝试.我们设计合成了1种含有甲基硫侧链的结晶性CTFs用于高效去除Hg^(2+),吸附容量为751 mg·g^(-1),与先前报道的Hg^(2+)吸附剂相比,性能优异,这项工作可能为实现多种分离应用的COFs的合成提供更多可能性.