Tetrazine‐Linked Covalent Organic Frameworks With Acid Sensing and Photocatalytic Activity

Abstract

The first synthesis and comprehensive characterization of two vinyl tetrazine‐linked covalent organic frameworks (COF), TA‐COF‐1 and TA‐COF‐2, are reported. These materials exhibited high crystallinity and high specific surface areas of 1323 and 1114 m2g–1. The COFs demonstrated favorable band positions, and narrow band gaps suitable for light‐driven applications. These advantages enabled TA‐COFs to act as reusable metal‐free photocatalysts in the arylboronic acids oxidation and light‐induced coupling of benzylamines. In addition, these TA‐COFs showed acid sensing capabilities, exhibiting visible and reversible color changes upon exposure to HCl solution, HCl vapor, and NH3 vapor. Furthermore, the TA‐COFs outperformed a wide range of previously reported COF photocathodes. The tetrazine linker in the COF skeleton represents a significant advancement in the field of COF synthesis, enhancing the separation efficiency of charge carriers during the photoreaction and contributing to their photocathodic properties. TA‐COFs can also degrade 5‐nitro‐1,2,4‐triazol‐3‐one (NTO), an insensitive explosive present in industrial wastewater, in 20 minutes in a sunlight‐driven photocatalytic process. Thus, revealing the dual functionality of the protonated TA‐COFs as both photodegradation and Brønsted acid catalysts. This pioneering work opens new avenues for harnessing the potential of the tetrazine linker in COF‐based materials, facilitating advances in catalysis, sensing, and other related fields.This article is protected by copyright. All rights reserved