Ultrastable Covalent Organic Frameworks via Self-Polycondensation of an A₂B₂ Monomer for Heterogeneous Photocatalysis

Abstract

Easy preparation, high stability, prominent activity, and excellent recyclability are four key elements for high-performance heterogeneous photocatalysts. Developing covalent organic framework (COF)-based heterogeneous photocatalysts possessing all of these traits is highly challenging. In this study, we successfully synthesized an imine-linked BBO-COF by the "two-in-one" strategy featuring the above four merits. Highly crystalline and porous BBO-COF can be easily prepared in at least 11 different simplex solvents independent of their polarity and boiling points and even under an air atmosphere. Moreover, BBO-COF exhibits extraordinary chemical stability and photostability in strong acid (12 M HCl), corrosive base (12 M NaOH), and visible light for 7 days. Furthermore, BBO-COF exhibited prominent photocatalytic activity toward oxidative hydroxylation reaction of arylboronic acids with excellent substrates tolerance and reusability. This "two-in-one" design strategy open a new avenue for facile constructing novel functional COFs with tailor-made properties.