Simultaneous Determination of Cd²⁺, Cu²⁺, Pb²⁺ and Hg²⁺ Based on 1,4‐Benzenedithiol‐2,5‐diamino‐hydrochloride‐1,3,5‐triformylbenzene Covalent‐Organic Frameworks

Abstract

Industry wastewater without purification treatment might contain heavy metal ions (HMIs), and the HMIs in water can induce various diseases regional outbreaks. It is necessary to monitor trace heavy metal ions in water samples. Herein, a covalent‐organic frameworks (COFs), COFBTLP‐1, is synthesized via a solvothermal reaction between 1,3,5‐triformylbenzene and 2,5‐diamino‐1,4‐benzenedithiol dihydrochloride. Two‐dimensional (2D) COFs nanosheets can be easily ultrasonically peeled from the bulk COFs. The COFs nanosheets were porous and flexible. And there are 24 metal ions adsorption sites on every cyclical structure of the COFs, provided by 12 S atoms and 12 N atoms on it. The 2D COFs nanosheets can be directly modified on the glassy carbon electrode without adhesive reagent and conductive reagent. The modified electrode shows high accuracy, high sensitivity, and low limit of detection for the simultaneous determination of four kinds of HMIs, Cd2+, Cu2+ Pb2+, and Hg2+.

Rapid, simple, and simultaneous electrochemical determination of cadmium, copper, and lead in Baijiu using a novel covalent organic framework based nanocomposite

“…Designing new working electrode materials or developing new methods to modify the working electrode is the key problem to improve the performance of electrochemical sensors for the HMIs detection ( Zhou et al, 2017 ). In recent years, various nanomaterials have been widely used as electrode modifiers in the preparation of electrochemical sensors because of their large specific surface area, abundant active sites and high adsorption capacity for HMIs ( Karimian et al, 2019 ; Yu et al, 2020 ). Covalent organic frameworks (COFs), connected by organic ligands through strong covalent bonds, are periodic stacked porous crystalline polymers composed of C, H, O, N, B and other light elements ( Tan et al, 2021 ).…”

Highly efficient determination of Mn2+ in Chinese liquor by using a novel electrochemical sensor based on TiO2-NH2@covalent organic framework nanocomposites

“…20,21 Many porous materials have been widely employed for the preparation of such sensors, such as TiO 2 , porous aluminosilica, and other inorganic materials as well as metal organic frameworks (MOFs), covalent organic frameworks (COFs) and other emerging crystalline porous materials. 22,23 Particularly, MOFs and COFs have abundant adsorption sites to recognize and adsorb HMIs and regular pores to facilitate the transfer of HMIs. 24 Compared with MOFs, COFs do not contain metal ions, but have ultra-high stability, and thus have greater potential in detecting HMIs.…”

Porous carbon nanosheets derived from two-dimensional Fe-MOF for simultaneous voltammetric sensing of dopamine and uric acid

“…COF is a kind of crystalline porous polymer, which is composed of organic units linked via covalent bonds [31]. 2D COF materials containing heteroatoms can be can peeled off from bulk COF by mechanical stripping [32]. However, its further application is restricted by the high cost of organic ligands, tediously synthesis periods and low yields.…”