Superhydrophobic Phosphonium Modified Robust 3D Covalent Organic Framework for Preferential Trapping of Charge Dispersed Oxoanionic Pollutants

• Published in: Advanced functional materials 2022-09, Vol.32 (36), p.n/a
• Main Authors: Wang, Yue, Lan, Jianhui, Yang, Xiaofan, Zhong, Shouchao, Yuan, Liyong, Li, Jiuqiang, Peng, Jing, Chai, Zhifang, Gibson, John K., Zhai, Maolin, Shi, Weiqun
• Format: Article
• Language: English
• Subjects: Anions; charge dispersed anions; covalent organic frameworks; Dispersion; distribution coefficient; Drinking water; gamma radiation modifications; Gamma rays; Groundwater; Hydrophilicity; Hydrophobic surfaces; Hydrophobicity; Ions; Materials science; Pollutants; Remediation; Robustness; Solvation; superhydrophobic phosphoniums
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202205222

Charge dispersed and less hydrophilic anionic pollutants are often difficult to be preferentially captured by common cationic framework materials. A gamma radiation modification approach is employed to anchor a superhydrophobic phosphonium‐containing coating on a robust crystalline 3D covalent organic framework (COF). By regulating the surface hydrophobicity, the prepared 3DCOF‐g‐VBPPh3Cl is endowed with a strong affinity for charge dispersed and less hydrophilic oxoanions, such as MnO4−, TcO4− and ReO4−, to surmount the Hofmeister bias, which much favors remediation of oxoanionic pollutants in complex aqueous systems. Batch and column experiments with 3DCOF‐g‐VBPPh3Cl in both tap water and simulated groundwater are performed, and rapid sequestration is achieved with removal efficacy up to 99.995%, record‐high distribution coefficient of 1.0 × 108 mL g−1, and desirable priority over competing anions such as Cl−, SO42−, HCO3−, and NO3−, confirming promise for remediation of charge dispersed anionic pollutants. Theoretical calculations reveal a mechanism of preferential capture based on electrostatic and dispersion interaction between charge dispersed anions and 3DCOF‐g‐VBPPh3Cl that effectively competes with solvation of the aqueous anions. Here, a gamma radiation modification approach is employed to anchor a superhydrophobic phosphonium‐containing coating on a robust crystalline 3D covalent organic framework (COF). Both batch and column experiments confirm that the prepared COF is endowed with a strong affinity for charge dispersed and less hydrophilic oxoanions to surmount the Hofmeister bias, which much favors remediation of oxoanionic pollutants in complex aqueous systems.