Covalent organic frameworks monolayer: Accurate syntheses and advanced application

Covalent organic frameworks (COFs) monolayer, with atomically thin, ordered networks and rich functionality, are widely studied due to their unusual structure/property relationships. However, synthesizing COFs monolayer has remained an unmet challenge due to the difficulty of controlling reactions at the monolayer limit with large-scale uniformity. The identification and development of new reactions and polymerization conditions are critical for the further advancement of COFs monolayer materials. Moreover, as one-molecule-thick, freestanding films, COFs monolayer offer an ideal material system. Many advanced applications of COFs monolayer have been explored in recent literature. This review provides an overview of the current state of precise synthetic strategies for COFs monolayer, highlighting the advantages and limitations of different synthetic approaches, key challenges related to enhancing quality, and emphasizing the unique benefits of COFs monolayer as both an ideal model system and for advanced applications.