Shape-controllable preparation of covalent organic frameworks and their application in efficient removal of aromatic organic pollutants

Abstract

Covalent organic frameworks (COFs), as well-ordered porous materials, have garnered considerable attention in the adsorption of environmental contaminants due to their long-range ordered crystal structure, great specific surface area, etc. In this work, alcoholic solvents were used as the reaction media to successfully synthesize three COFs with regular crystalline structures under nearly ambient conditions, whereas conventional synthetic techniques have not been documented for the synthesis of TAPB-TFPT COFs. Inspired by the excellent physical and chemical properties of the generated rod-like TAPB-DHTP COFs, which can be served as an ideal solid adsorbent for aromatic organic pollutant adsorption and removal. It is worth mentioning that TAPB-DHTP COFs showed fast adsorption kinetic rates (within 40 min) and high adsorption capacities (288 mg/g, 87.7 mg/g and 105 mg/g) for naphthalene, 2-naphthol and 2-naphthylamine, superior to most reported adsorbents. The effective removal of aromatic organic pollutants is ascribed to numerous non-covalent interactions between targets and TAPB-DHTP COFs, including π-π interactions and hydrogen bonding. Thus, this research might present a promising route to the green preparation of COFs and their prospective application in environmental restoration.