Affiliation:
1. 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
2. University of Chinese Academy of Sciences Beijing 100049 P. R. China
3. CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology Beijing 100190 P. R. China
4. Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry Technische Universität Dresden 01062 Dresden Germany
Abstract
AbstractThe tunable pore walls and skeletons render covalent organic frameworks (COFs) as promising absorbents for gold (Au) ion. However, most of these COFs suffered from low surface areas hindering binding sites exposed and weak binding interaction resulting in sluggish kinetic performance. In this study, COFs have been constructed with synergistic linker and linkage for high‐efficiency Au capture. The designed COFs (PYTA‐PZDH‐COF and PYTA‐BPDH‐COF) with pyrazine or bipyridine as linkers showed high surface areas of 1692 and 2076 m2 g‒1, providing high exposed surface areas for Au capture. In addition, the Lewis basic nitrogen atoms from the linkers and linkages are easily hydronium, which enabled to fast trap Au via coulomb force. The PYTA‐PZDH‐COF and PYTA‐BPDH‐COF showed maximum Au capture capacities of 2314 and 1810 mg g−1, higher than other reported COFs. More importantly, PYTA‐PZDH‐COF are capable of rapid adsorption kinetics with achieving 95% of maximum binding capacity in 10 min. The theoretical calculation revealed that the nitrogen atoms in linkers and linkages from both COFs are simultaneously hydronium, and then the protonated PYTA‐PZDH‐COF are more easily binding the AuCl4‒, further accelerating the binding process. This study gives the a new insight to design COFs for ion capture.
Funder
National Natural Science Foundation of China
Youth Innovation Promotion Association of the Chinese Academy of Sciences