Enhanced Antibiotic Pollutant Capture: Coupling Carbon Nanotubes with Covalent Organic Frameworks

Abstract

Antibiotics, recognized for their toxicity and persistence in aquatic environments, are emerging pollutants, prompting extensive research into removal technologies. The exclusion mechanisms of antibiotics (NOPs) such as norfloxacin (NOR), ofloxacin (OFL), and pefloxacin (PEF) on novel covalent organic frameworks (COFs) and COF composites with carbon nanotubes (CNTs@COFs) were examined through molecular dynamics and metadynamics simulations. Our simulation results indicate that van der Waals (vdW) interactions are the primary attractive forces in the formation of NOP/COF and NOP/CNTs@COF complexes; however, electrostatic (Elec) and hydrophobic forces also play crucial roles. The energy analysis revealed that NOPs were adsorbed more rapidly onto CNTs@COFs, and the PEF-COF and CNTs@COFOFL systems have the highest interaction energy. The total interaction energies were found to be −246.154 and −358.626 kJ mol−1 for PEF-COFs and CNTs@COFs-OFL, respectively. These results from metadynamics simulations were further confirmed via molecular dynamics (MD) analysis, which showed that PEF-COFs and CNTs@COFs-OFL had higher free energy values when positioned closer to substrates.