Design Strategies and Application Progress of Covalent Organic Frameworks in Photocatalytic Oxidation Reactions

Abstract

Photocatalytic generation of reactive oxygen species (ROS) presents a sustainable alternative to traditional oxidation methods, offering precise control over reaction pathways for diverse applications. Covalent organic frameworks (COFs), with their crystalline porous structures and tunable electronic properties, are ideal platforms for maximizing photocatalytic ROS efficiency and selectivity. This review systematically explores the intrinsic connection between COF architecture and ROS activity, framed by a "Structure–ROS–Substrate" paradigm. We detail how rational design strategies—such as donor–acceptor engineering, π-conjugation extension, functional group integration, and pore microenvironment regulation—precisely modulate band structures, charge carrier dynamics, and mass transport to govern ROS speciation (e.g., •OH, ¹O₂, H₂O₂) and concentration. These structural innovations underpin the remarkable performance of COFs in photocatalytic oxidation, including selective organic transformations (e.g., amine-to-imine conversion), sustainable H₂O₂ production, and efficient degradation of recalcitrant pollutants. The application scope is further extended to biomedical fields, leveraging ROS for antibacterial therapy and photodynamic effects. Finally, we discuss prevailing challenges in quantitative ROS detection, operational stability, and scalable synthesis, while outlining future opportunities in machine-learning-guided design and tandem catalytic systems. This review aims to establish fundamental design principles for the next generation of COF-based photocatalysts, bridging molecular-level engineering to macroscopic oxidative efficacy.