The strategy of three-dimensional Covalent Organic Frameworks to exclude dye contaminants in aqueous solutions

Abstract

Abstract The development of effective solid adsorbents is necessary to remove organic pollutants from wastewater in response to the global water crisis. The present study investigates the adsorption behavior of dye pollutants on a 1, 3, 6, 8-tetrakis (4formylphenyl) pyrene (TFPPy) for the self-assembly of an innovative three-dimensional (3D) covalent organic frameworks (COFs). Molecular dynamics (MD) and the well-tempered metadynamics simulation were used to evaluate the ability of COFs to adsorb seven types of dye pollutants (DPs). These include methyl orange (MO), gentian violet (GV), brilliant green (BG), tolonium chloride (TC), methylene blue (MB), anionic congo red (CR), and rhodamine B (Rh B). To examine this process, several descriptors are calculated from the simulation trajectories, including interaction energies, root-mean-square deviation, radial distribution function, solvent-accessible surface area, mean square displacement, and the number of hydrogen bonds to figure out the process. After analyzing the data, it was found that the MO/COFs system displayed exceptional stability. It was confirmed by a significant value of −448.54 KJmol−1 for total interaction energy. The density profile of dye molecules in the MO and Rh B-COFs systems exhibits the highest peaks at approximately 325.79, and 26.75 kg/m³, respectively. The free energy values for the DPs/COFs complexes at their global minima reached about, −512.127, −435.603, −381.244, −300.313, and −283.230 kJmol-1 for MO/GV/BG/TC/ and Rh B with the COFs, respectively. The nature of the design of TFFPy-COF’s unique, ultrafast kinetics, high adsorption capacity, and good reusability endow them with great potential for removing dyes in an aqueous environment.