# Covalent organic imine polymer containing benzothiadiazole as a bifunctional material for specific fluorescence detection and removal of Hg2+

## TL;DR

A new covalent organic polymer material was developed to detect and remove mercury ions effectively.

## Contribution

The study introduces a bifunctional covalent organic imine polymer for simultaneous Hg2+ detection and removal.

## Key findings

- The material achieves Hg2+ detection with a limit of 35.65 µM.
- It has a high removal capacity of 475 mg g−1 for Hg2+.
- The material shows excellent selectivity and reusability for Hg2+ adsorption.

## Abstract

As one of the most toxic heavy metals to humans and the environment, achieving simultaneous fluorescence detection and effective removal of Hg2+ presents a significant challenge. In this study, we combined the excellent photoelectric properties of benzothiadiazole groups with the porous structure of covalent organic polymers (COPs) to develop a novel covalent organic polymer material (BTD-MPD-COP) with enhanced fluorescence performance. The benzothiadiazole-modified sites in this material achieved the bifunctional application of BTD-MPD-COP for Hg2+ fluorescence detection with a detection limit of 35.65 µM and simultaneous removal with a capacity of 475 mg g−1. Furthermore, BTD-MPD-COP demonstrated remarkable Hg2+ selectivity and can be reused after desorption without significant reduction in its adsorption capacity. This indicates that BTD-MPD-COP possesses excellent dynamic reversibility in the adsorption of Hg2+. In summary, the development of functionalized bifunctional covalent organic polymer materials presents an effective strategy for simultaneous removal and detection of toxic heavy metal ions.

As one of the most toxic heavy metals to humans and the environment, achieving simultaneous fluorescence detection and effective removal of Hg2+ presents a significant challenge.