Zhang Qing Yun,Zhang Lin Juan,Zhu Jian Qiu,Gong Le Le,Huang Zhe Cheng,Gao Feng,Wang Jian Qiang,Xie Xian Qing,Luo Feng
With the rapid development of nuclear energy, problems with uranium supply chain and nuclear waste accumulation have motivated researchers to improve uranium separation methods. Here we show a paradigm for such goal based on the in-situ formation of π - f conjugated two-dimensional uranium-organic framework. After screening five π -conjugated organic ligands, we find that 1,3,5-triformylphloroglucinol would be the best one to construct uranium-organic framework, thus resulting in 100% uranium removal from both high and low concentration with the residual concentration far below the WHO drinking water standard (15 ppb), and 97% uranium capture from natural seawater (3.3 ppb) with a record uptake efficiency of 0.64 mg·g −1 ·d −1 . We also find that 1,3,5-triformylphloroglucinol can overcome the ion-interference issue such as the presence of massive interference ions or a 21-ions mixed solution. Our finds confirm the superiority of our separation approach over established ones, and will provide a fundamental molecule design for separation upon metal-organic framework chemistry.
In recent years, ion covalent organic frameworks (iCOFs) have shown excellent adsorption performance in the removal of non-steroidal anti-inflammatory drugs (NSAIDs), but powdered iCOFs are faced with problems in separation and recovering from solution and are prone to environmental pollution. In this work, polydopamine (PDA) was used as the mediated coating, Fe 3 O 4 as the magnetic nucleus, and iCOFs consisting of benzene-1,3,5-triscarbaldehyde (BT) and 1,3-diaminoguanidine hydrochloride (DG Cl ) as organic ligands were in-situ grown on the surface of the PDA coating by Schiff base reaction, resulting in a magnetic nanocomposite (Fe 3 O 4 @PDA@BT-DG Cl ) with a coral-like structure. The adsorption kinetics and adsorption isotherms showed that the adsorption behavior of diclofenac sodium (DS) on Fe 3 O 4 @PDA@BT-DG Cl followed the pseudo-second-order kinetic model and Langmuir model, and the maximum adsorption capacity could reach up to 420.17 mg g −1 (25 ℃, pH 5). The adsorption of DS on Fe 3 O 4 @PDA@BT-DG Cl was dominated by electrostatic interactions, along with hydrogen bonding, π-π interactions, and ion exchange, according to the analysis of the adsorption mechanism. The Fe 3 O 4 @PDA@BT-DG Cl consistently maintained high adsorption efficiency after six adsorption–desorption cycles, making it an efficient adsorbent for the removal of NSAIDs in complex water environments.
危险品化学品经营许可证（带存储）