Regulating Functionalities in a Photoactive Covalent Organic Framework for Selectively Synergistic Efficiency Enhancement in Photocatalytic Aerobic Oxidations

Abstract

Besides the active sites, regulating the functionalities in photocatalysts is also crucial for enhancing photocatalytic efficiency. Herein, an imine‐linked 3D covalent organic framework, Py‐PA‐COF, with pts topology was synthesized and after modulating the pore microenvironment by grating different functionalities (benzene, benzoic acid, pyridine) into the pristine framework, three quinoline‐linked COFs, Py‐PA‐COF‐Q, Py‐PA‐COF‐QA, Py‐PA‐COF‐QB with analogous network were successfully obtained. Experimental analyses demonstrate that the incorporated functionalities not only enhanced their efficiency of charge separation and migration, but also synergistically increased the photocatalytic activity toward specific substrates. Interactions analyses by steady‐state photoluminescence spectroscopy and the Dual Descriptor isosurface distribution calculations revealed that the inherent interactions between the substrates and the functionalities can enhance the mass transfer capability in the COF‐based photocatalysts and thereby beneficial for the rapid transfer of generated ROS to the reaction substrates and avoiding self‐quenching and finally therefore synergistically enhance their photocatalytic reactivity. This work demonstrates the selectively synergistic enhancement of the photocatalytic efficiency by modulating functionalities in photoactive COFs and provides a new insight for photocatalyst design.