Covalent Organic Frameworks as Photocatalysts for Sustainable Solar-to-Hydrogen Peroxide Conversion.

Hydrogen peroxide (HO) plays a pivotal role in energy and environmental applications, but its industrial synthesis remains hampered by high energy consumption, environmental concerns, and safety risks. Artificial photosynthesis offers a sustainable alternative by leveraging solar energy to catalyze HO production from oxygen and water. Covalent organic frameworks (COFs) have emerged as promising photocatalysts due to their well-defined structures and customizable active sites, enabling efficient solar-to-chemical conversion (SCC). This review comprehensively explores recent progress in COF-mediated photocatalytic HO synthesis. It begins with an overview of photocatalytic principles, followed by a detailed analysis of reaction mechanisms and performance metrics for HO generation. Emphasis is placed on tailored COF design strategies-such as electronic structure optimization and redox-active site engineering-to improve catalytic efficiency. Finally, we identify key challenges hindering the development of high-performance COFs photocatalysts tailored for sustainable H₂O₂ synthesis.