Covalent organic frameworks as efficient adsorbent for sulfamerazine removal from aqueous solution.

Here, TPB (triphenylbenzene) - DMTP (dimethoxyterephthaldehyde) -COF was prepared, characterized and used as effective adsorbent for the removal of sulfamerazine (SMT) from aqueous solution. Its adsorption characteristics and mechanism were explored. With large channel (∼3.3 nm), high specific surface area (2115 m2/g), and high crystallite, TPB-DMTP-COF showed high adsorption capacity (209 mg/g), fast adsorption equilibrium (80 min), and good reusability. Natural pH condition was optimal for its adsorption capacity, while electrostatic repulsion between TPB-DMTP-COF and SMT accounted for the low adsorption performance at acidic or alkaline conditions. According to the DFT method, SMT molecules adsorbed in the pore-sites of COFs via C-H···π interaction was the predominant and stable adsorption configuration accounting for the efficient removal of SMT in large quantity. This study revealed the great adsorption potential of COFs skeleton itself in the application of environmental remediation.