Tuning the pore structures and photocatalytic properties of a 2D covalent organic framework with multi-branched photoactive moieties

Abstract

In this study, a new strategy to establish a 3D local connection of building synthons and tune the functionalities of 2D covalent organic frameworks (COFs) was developed via in situ incorporation of multi-branched building blocks during the synthesis of COFs. The new COF material CPF-3 retains the features including surface area, crystallinity and stability of the pristine 2D COF COF-LZU1 and expands the light absorption range to the visible-light region via incorporation of accessible photoactive porphyrin sites with the 3D local connection. The Sn(IV)-metalated COF material Sn-CPF-3 exhibits high photocatalytic efficiency and selectivity in aerobic oxidation of sulfides to produce highly value-added sulfoxides with up to 23 334 turnovers and 648 h⁻¹ turnover frequency under visible light irradiation.