Metal-Free Fenton-like Photocatalysts Based on Covalent Organic Frameworks

The Fenton reaction is one of the most efficient and widely used advanced oxidation processes for remediating the ever-growing water pollution. Metal-free photocatalysts for Fenton-like reactions have gathered enormous scientific interest for their advantages including board pH operation range and high stability. Herein, we demonstrate a metal-free covalent organic framework (COF)-based standalone photocatalyst with superior reactivity and reusability for Fenton-like reactions at acid and neutral pH solutions, which can be attributed to its large porosity, high density of the photoactive triazine moiety, vertical π arrays formed by eclipsed layer stacking and the β‑ketoenamine linkage. Our experiments showed that the photocatalyst can absorb visible light effectively for activation of H₂O₂, producing abundant reactive oxygen species including superoxide radical (O₂^·-), hydroxyl radical (^·OH), and singlet oxygen (¹O₂) for oxidizing organic pollutants. This work not only provides an efficient metal-free photocatalyst for Fenton-like reactions, but also paves the way for COFs towards advanced oxidation processes, opening up the possibilities to their future applications in industry.