2D sp2 carbon-conjugated triazine covalent organic framework photocatalysis for blue light-induced selective oxidation of sulfides with O2

Abstract

Triazine, possessing planar and fully conjugated attributes, purveys ample space to construct well-defined crystalline polymers like graphic carbon nitrides (g-C3N4), covalent triazine frameworks (CTFs), and covalent organic frameworks (COFs). Herein, g-C3N4, CTF-1, and TP-COF were successfully synthesized and systematically confirmed by a series of characterizations, aiming at visible light photocatalytic activation of O2. Compared to CTF-1 and g-C3N4, TP-COF was endowed with the best photocatalytic performance by several inherent properties, including a large specific surface area, a suitable bandgap, and superior charge transfer. The blue light-induced selective conversion of organic sulfides has been achieved expeditiously with O2 over TP-COF photocatalyst. Moreover, rigorous control experiments and in situ electron paramagnetic resonance (EPR) suggest that electron and energy transfer pathways contribute to the selective formation of desired sulfoxides. This work emphasizes that the tailor-made trait of COFs provides an ideal plarform of customizing two-dimensional (2D) photoactive COFs based on triazine for visible light-induced selective chemical transformations.