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Utilizing weak interactions to effectively recover and separate precious metals in solution is of great importance but the practice remains a challenge. Herein, we report a novel strategy to achieve precise recognition and separation of gold by regulating the hydrogen‐bond (H‐bond) nanotrap within the pore of covalent organic frameworks (COFs). It is found that both COF‐HNU25 and COF‐HNU26 can efficiently capture AuIII with fast kinetics, high selectivity, and uptake capacity. In particular, the COF‐HNU25 with the high density of H‐bond nanotraps exhibits an excellent gold uptake capacity of 1725 mg g−1, which is significantly higher than that (219 mg g−1) of its isostructural COF (COF‐42) without H‐bond nanostrap in the pores. Importantly, the uptake capacity is strongly correlated to the number of H‐bonds between phenolic OH in the COF and [AuCl4]− in water, and multiple H‐bond interactions are the key driving force for the excellent gold recovery and reusability of the adsorbent. [ABSTRACT FROM AUTHOR]

As a new type of porous crystalline material, covalent organic frameworks (COFs) have shown great potential in many application fields. Postsynthetic modification (PSM) is a prevalent and useful strategy for producing new COFs with desired functionalities. Herein, we report a general method for COF post-functionalization that involves the introduction of amino functional groups (–NH2) into the framework as anchoring sites. By this strategy, a variety of COFs with desired functionalities were prepared under ambient conditions by transforming –NH2 into imine, thiourea, amide and azo-based functional groups. We believe this work will provide an opportunity to create porous materials with augmented properties and performances and expand their practical application. [ABSTRACT FROM AUTHOR]