Covalent Organic Framework for Photocatalytic Hydrogen Peroxide Production: A Green Pathway

Artificial photosynthesis offers a sustainable approach to harnessing solar energy and converting it into valuable chemical fuels. Among the renewable products, hydrogen peroxide (H2O2) has gained significant attention as a green oxidant with wide industrial and environmental applications. Nevertheless, its photocatalytic generation is constrained by the limited efficiency, stability, and selectivity of existing materials. This article presents a comprehensive overview of recent advances in methods and materials for photocatalytic H2O2 production, emphasizing how synthetic innovations and structural design have improved light absorption, charge transfer, and surface reactivity. In this perspective, the mechanistic insights into the oxygen reduction and water oxidation pathways have been discussed to clarify factors governing activity and selectivity. Particular focus is placed on covalent organic frameworks (COFs), a class of crystalline, porous, and metal-free photocatalysts with tunable architectures, extended π-conjugation, and high photochemical stability. Their emergence has enabled rational strategies such as donor–acceptor engineering, functional group incorporation, and architecture modulation to suppress H2O2 decomposition and enhance yields. Representative examples are critically evaluated to highlight strengths and limitations, while future challenges, including stability under practical conditions and scalability, are addressed. Overall, this article highlights the potential of COF-based photocatalysts in promoting solar-driven H2O2 production.