Highly efficient adsorption and capture of prevalent phenolic contaminants from the real samples by trifluoromethyl-functionalized covalent organic frameworks

The specific removal of phenolic pollutants from aqueous medium based on the functionalized materials are great significant for the adsorption processes. The purposes of this work were to fabricate fluorine-containing covalent organic frameworks (COFs) sorbent with hydrophobic function and hydrogen bond acceptor capacity to investigate the key role of fluorine functional group in the sorption behavior for phenolic pollutants in the aqueous solutions. Here, two fluorinated COFs, named TFPT-PI-CF3 and TFPT-PI-2CF3, were facilely synthetized through the imine condensation reaction between tri-aldehyde and diamine pre-modified by trifluoromethyl group. The adsorption isotherms, kinetics, thermodynamic, and reusability of tow COFs for the adsorption and capture of prevalent phenolic contaminants (hydroquinone, catechol, resorcinol, phenol, and acetaminophen) from aqueous solution were inspected in detail. The maximum adsorption capacity for TFPT-PI-CF3 and TFPT-PI-2CF3 was calculated to be 576 and 567 mg·g−1 for hydroquinone by using linear Langmuir isotherm as an appropriate model, respectively. Adsorption mechanisms highlighted the synergistic effects of F–H hydrogen bonding and hydrophobic interactions as important design criteria for efficient removal of phenolic pollutions from water medium. Furthermore, the prepared fluorinated COFs were successfully applied to evaluate five phenolic contaminants in real water samples, which demonstrated that the fluorine-containing materials held great promise for the development of an accurate platform for the rapid removal of the hydroxyl contaminants.