Simply-prepared hollow covalent organic framework as a dual-function platform for detection and removal of multiple heavy metal ions

Abstract

Covalent organic frameworks (COFs) show great advantage in heavy metal ions detection and removal due to their large specific surface area, high porosity, excellent stability, and abundant functional sites. While current research primarily focuses on the influence of COF composition on detection and adsorption performance, the influence of COF′s morphology is often overlooked. In this study, a hollow structured TB-HCOF was developed through simple amorphous-to-crystalline transformation strategy involving the reaction between 1,3,5-Tris (4-aminophenyl) benzene (TAPB) and 1,3,5-benzenetricarbaldehyde (BTCA). TB-HCOF combine the advantages of COFs with the unique properties of hollow structure, such as an enlarged surface area, shortened diffusion distance, and easily accessible functional sites. It exhibited exceptional adsorption performance for heavy metal ions with the maximum adsorption capacities of 766.28 mg·g−1 for Pb2+, 759.32 mg·g−1 for Cu2+, and 640.83 mg·g−1 for Hg2+. Additionally, yolk-shell Pt nanoparticles@TB-HCOF was designed as an electrochemical sensing platform for heavy metal ions detection. Thanks to the synergistic effect between TB-HCOF with exceptional adsorption capacity and Pt nanoparticles with remarkable electrical conductivity, the sensor displayed awesome detection performance toward Pb2+, Cu2+ and Hg2+ with low limits of detection of 0.11 ng·L-1. These findings highlight the potential of simply-prepared hollow COFs as a promising material for managing heavy metal ions pollution.