Backbone engineering and side group manipulation in covalent organic frameworks for overall solar-driven hydrogen peroxide production

Covalent Organic Frameworks (COFs) have emerged as highly promising materials for the photocatalytic production of hydrogen peroxide (H₂O₂) due to their exceptional structural tunability, robust frameworks, and high porosity. The efficient overall photosynthesis of H₂O₂ hinges on the simultaneous occurrence of the oxygen reduction reaction (ORR) and water oxidation reaction (WOR). This review introduces recent progress in developing key approaches such as backbone engineering and the incorporation of side groups to facilitate these critical reaction pathways. For example, innovative COF designs, such as spatially separating redox centers, have demonstrated significant improvements in photocatalytic performance. Moreover, the introduction of thioether-decorated triazine-based COFs and hexavalent triphenylene knots has led to remarkable H₂O₂ production rates. Furthermore, this review also addresses the challenges associated with the practical implementation of COFs, including their stability under operational conditions and the necessity for innovative reactor designs. The future prospects of COFs in sustainable chemical synthesis are also discussed, emphasizing their potential for COFs to revolutionize H₂O₂ production through green and sustainable methodologies. This review aims to provide valuable insights into the design and development of high-performance COF photocatalysts, paving the way for their practical applications in the sustainable production of value-added chemicals.