Synthesis of porphyrin nanodisks from COFs through mechanical stirring and their photocatalytic activity

Abstract The synthesis of thin-layered two dimensional (2D) organic nanomaterials has recently attracted considerable attention because of their potential for use in photo-electrochemistry and photocatalysis. To synthesize thin-layered organic polymers such as polymer nanosheets and nanodisks, covalent organic frameworks (COFs) with benzene or triphenylbenzene core units, are immersed or mechanically sonicated in common solvent. However, it is still challenging to exfoliate the π-conjugated COFs containing such porphyrin units. In this study, we investigated the liquid-phase exfoliation of COFs comprising porphyrin using common solvents, and found that tuning the solvent surface energy as well as mechanical stirring is crucial for effective exfoliation. We synthesized thin-layered, covalent organic porphyrin nanodisks in a common solvent by mechanical stirring and observed their enhanced photocatalytic activity.