Modulator‐Assisted Photosynthesis: Green and Powerful Approach towards Superstructured π−Conjugated Covalent Organic Frameworks with Enhanced Electrochemical Performances

Abstract

AbstractFully aromatic π‐conjugated covalent organic frameworks (COFs) have garnered great attention because of their potential applications in optoelectronics and energy storage; however, achieving crystallinity is far from trivial mainly because most covalent bond connection in these π‐conjugated COFs have been deemed as an irreversible synthetic dead end because of aromatic stabilization. Here we report a green photosynthesis approach towards crystalline superstructured π‐conjugated COFs, the introduction of aromatic‐ortho‐diamine (o‐diamine) as dynamic modulator provide a powerful strategy to enhance the multi‐scale structure control and resulted in π‐conjugated COF with high crystallinity, rarely observed staggered AB stacking and uniform superstructured crystals of hundreds of micrometers. The mechanism behind this modulator‐assisted photosynthesis approach is a polymerization‐induced‐crystallization process. The prepared π‐conjugated crystalline framework displays superior electrochemical performance with a specific capacitance of more than 600 F g−1at a scan rate of 10 mV s−1, and excellent metal‐free 2e oxygen reduction reaction (ORR) electrocatalytic activity with peak potentials of 0.764 V with excellent cycling stability, these values are among the highest electrochemical performance reported for COF materials.