Structural optimization of ZIF-67 derived carbon materials for enhanced chlortetracycline adsorption

Abstract

ZIF-67-derived carbon materials demonstrate significant practical potential for the efficient adsorption of antibiotic contaminants in wastewater. Herein, we systematically explored the influences of the morphology of the precursor and carbonization conditions on the final structure and chlortetracycline (CTC) adsorption performance of ZIF-67-derived carbon materials. Co/Co3O4 decorated N doped carbon nanosheets (C700) were finally synthesized by using a unique petal-like lamellar structured ZIF-67 precursor through a molten salt-assisted carbonization method at 700 °C. The CTC adsorption process and mechanism on C700 were further investigated. The maximum CTC adsorption capacity of C700 was determined to be 3639 mg/g. It is demonstrated that the CTC adsorption on C700 is a chemisorption predominated complex process that involves multi-affinities, including π-π EDA interactions, cation-π interactions, coordination bonds, hydrogen bonds, and electrostatic interactions. The excellent CTC adsorption performance of C700 is primarily attributed to the full exposure of adsorption active sites on the external surface. This work provides a new insight into the structural optimization of ZIF-67-derived carbon materials and their practical application in antibiotic wastewater treatment.