Yang Xiubei, Jiang Di, Cheng Yuanzhe, Fu Yubin, Li Xuewen, Liu Guojuan, Ding Xuesong, Han Bao-Hang, Xu Qing, Zeng Gaofeng
CAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute (SARI), Chinese Academy of Sciences (CAS), Shanghai, 201210, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Small Methods. 2024 Dec 1:e2401792. doi: 10.1002/smtd.202401792.
Covalent organic frameworks (COFs) with high surface areas and specialized binding sites garnered attention in the field of gold (Au) adsorption. The adsorption capacity mostly depends on the functional skeletons and porous structures, however, the roles of linkages have not been thoroughly explored. In this study, imidazopyridinium-linked COFs, specifically im-PYTA-PZDH-COF and im-PYTA-BPDH-COF were synthesized, to enhance gold adsorption efficacy. These engineered COFs exhibit excellent crystallinity and high surface areas, with the charged linkages demonstrating a strong binding ability for Au, which results in high Au uptake and rapid adsorption kinetics. The optimized COF, im-PYTA-PZDH-COF, offered a maximum adsorption capacity of 1558 mg g, achieving 95% of this capacity within a mere 10 min. Theoretical calculations further confirm that the carbon atoms adjacent to the nitrogen in the imidazopyridinium ring, serving as adsorption sites, directly interact with AuCl through coulombic forces, thereby enhancing both the adsorption capacity and rate. This work provides a new strategy for designing COFs for effective Au adsorption.
具有高比表面积和特定结合位点的共价有机框架（COFs）在金（Au）吸附领域引起了关注。吸附容量主要取决于功能骨架和多孔结构，然而，连接键的作用尚未得到充分探索。在本研究中，合成了咪唑并吡啶连接的COFs，特别是im-PYTA-PZDH-COF和im-PYTA-BPDH-COF，以提高金的吸附效率。这些工程化的COFs表现出优异的结晶度和高比表面积，带电荷的连接键对Au表现出很强的结合能力，这导致了高的Au摄取量和快速的吸附动力学。优化后的COF，即im-PYTA-PZDH-COF，最大吸附容量为1558 mg/g，在短短10分钟内即可达到该容量的95%。理论计算进一步证实，咪唑并吡啶环中与氮相邻的碳原子作为吸附位点，通过库仑力与AuCl直接相互作用，从而提高了吸附容量和速率。这项工作为设计用于有效吸附Au的COFs提供了一种新策略。
