Radiation synthesized carboxyl-functionalized covalent organic framework adsorbent for efficient heavy metal decontamination

Abstract

Carboxyl groups exhibit great potential in the field of heavy metal decontamination due to their good coordination ability. In this work, acrylic acid was grafted onto covalent organic framework (COF) by using a γ-ray radiation grafting approach. A carboxyl-functionalized adsorbent designated AA-TbDa-COF with high performance for multiple heavy metal removal was obtained. Infrared spectroscopy and thermogravimetric analysis proved the successful carboxyl modification. The porous nanofiber morphology and high accessibility of carboxyl functional groups give the resultant AA-TbDa-COF ultra-fast adsorption kinetics. The capacity for Pb2+, Cd2+ and Cu2+ decontamination was 127.9, 60.6 and 39.8 mg/g, respectively. The preparation of functional COFs by radiation method is extended to the field of heavy metal treatment, proving the great potential of radiation-prepared materials in environmental governance.