The Engineering Screen of Photoactive Nanozymes Based on N‐Containing Covalent Organic Frameworks for Antibacterial Application

Covalent organic frameworks (COFs) are a class of highly efficient photocatalytic organic semiconductor materials, which have been developed for the design of photoactive nanozymes. Nitrogen (N)-heterocycles could effectively improve their photocatalytic activity of COFs. However, the systematic exploration of photoactive nanozymes based on N-containing COFs is still lacking. In this work, a series of N-containing Schiff-base linkages of COFs are designed and synthesized to explore high-performance photoactive nanozymes. In addition, Fe ions are introduced through post-modification of COFs, which can not only effectively extend the band-edge absorption of COFs to the red-light region and thereby broaden its biological applications, but also introduce single site of Fe to enrich the types of free radicals in the catalytic products. The activities of photoactive nanozymes based on N-containing COFs are systematically studied, and their catalytic mechanisms are uncovered. Interestingly, it is not as commonly recognized that the more content of N, the better for photocatalysis or the construction of photoactive nanozyme. Furthermore, the selected photoactive nanozymes are used for antibacterial applications, which showed good activity against Escherichia coli.