A hydrazone-linked covalent organic framework with abundant N and O atoms for detecting heavy metal ions

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Switzerland), 2023-04, Vol.934, p.117307, Article 117307
• Main Authors: Peng, Canwei, Pei, Longsheng, Chen, Shouhui, Song, Yonghai, Wang, Li
• Format: Article
• Language: English
• Subjects: Covalent organic frameworks; Electrochemical sensing; Heavy metal ions; Hydrazone bond
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2023.117307

[Display omitted] •Using dialysis membrane promoted the spontaneous growth of 3D network TP-TD COF.•Intramolecular NH·· OC hydrogen bonding enhanced the stability of COF.•Abundant ONO in structure serves as the catalytic active site of heavy metal ions.•Simultaneous detecting of four HMIs with great electrochemical performance.•The sensor can be applied to the detection of heavy metal ions in river water. The bioaccumulation of heavy metal ions (HMIs), even at low concentrations, will lead to high toxicity. So, in this work, a hydrazone-linked covalent organic framework (COF) with abundant N and O atoms was prepared for sensitive HMIs detection. Under the room temperature, terephthaloyl dihydrazide (TD) and triformylphloroglucinol (TP) reacted to form the hydrazone bond, and a new hydrazone-linked TP-TD COF was prepared. During the reaction, enole-keto tautomerism occurred, and NH···OC hydrogen bond was formed, which improved the crystallinity and chemical stability of COF. Accordingly, the hydrazone-linked TP-TD COF presented three-dimensional network morphology. The porous channels could promote the migration of HMIs, and the affinity of N and O atoms to HMI was utilized. There were abundant O·N·O sites in each unit, so the hydrazone-linked TP-TD COF was applied to the sensing of HMIs. The electrochemical sensor constructed by TP-TD COF was used to detect Cd2+, Pb2+, Cu2+ and Hg2+ simultaneously. Under optimized conditions, the electrochemical sensor based on TP-TD COF showed fast response speed, sensitive detection ability and the potential for practical sample detection.