Dual-function Covalent Organic Polymers Rich in N, O, S Heteroatoms for Sensitive Detection and Efficient Capture of Mercury (II)

Abstract

As a serious threat to environmental safety and public health, mercury ((Hg2+) has been noted as a global hazard because of its high toxicity. Recently, significant effort has been invested in developing novel strategies for simultaneous detection and remove of Hg2+. Herein, we designed and synthesized three types of nitrogen-, oxygen- and sulfur-rich covalent organic polymers (COPs) for Hg2+ detection and adsorption from solutions. For comparison, the aldehydes building blocks containing one, two, or three thiophene rings condensed with the flexible hydrazide terephthalate to obtain the COPs named as HTDP-1, HTDP-2 and HTDP-3, respectively. With electron rich thiophene-bicyclic systems, the HTDP-2 exhibited a fast adsorption capacity for Hg2+ (91.2% within 10 min). In addition, the polymer also has excellent fluorescence properties, which can realize the fluorescence detection of Hg2+ in a with a detection limit of 0.70 ppm. This work provides a novel design concept for the rational construction of dual-function Hg2+ repair materials and broadens the application of COPs materials in the field of heavy metal ions detection and repair.