A novel nitrogen-containing covalent organic framework adsorbent for the efficient removal of bisphenol A from aqueous solution

Extensively used bisphenol A (BPA) in industry aggravates the pollution of water environment. Thus, we are committed to developing an efficient adsorbent to remove BPA, exploring the adsorption performance and mechanism. Here, a novel nitrogen-containing covalent organic framework, named PyTTA-Dva-COF as an effective adsorbent for removing BPA from aqueous solutions was prepared by a simple solvent-thermal method. PyTTA-Dva-COF exhibited uniform nanofibrous structure, abundant and robust C=N functional groups, as well as high chemical stability. The saturated adsorption capacity is 285 mg/g, and the adsorption process conforms to Langmuir isotherm model. The kinetic data conforms to the pseudo-second-order kinetic model, and the thermodynamic parameters, ∆G°<0 and ∆H°<0, indicated that the adsorption was a spontaneous exothermic process. The PyTTA-Dva-COF demonstrated excellent potential for environmental applications as verified through consistent BPA adsorption capacities under disparate pH values, testing in various water matrices, and repeated cycling tests. Furthermore, π-π interactions and hydrogen bonding were proved to be the major adsorption mechanism for BPA. These findings indicated the great potential of PyTTA-Dva-COF for the removal of BPA in water environment.