Self‐Floating Photocatalytic System for Highly Efficient Hydrogen Peroxide Production and Organic Synthesis on Carbon Dots Decorated Conjugated Microporous Polymer

Abstract Photocatalytic oxygen (O 2 ) reduction to hydrogen peroxide (H 2 O 2 ) is considered to be a promising method for energy storage. However, it suffers from the rapid recombination of carriers, the limited solubility and slow diffusion of O 2 , and the self‐decomposition of H 2 O 2 in traditional diphase systems. Here, a self‐floating carbon dots/conjugated microporous polymer (CDs/CMP) photocatalytic system is established for H 2 O 2 production and organic synthesis. Due to the D–π–A structure, porous structure, and hydrophobicity, CMP induced the intramolecular charge transfer, exposed abundant reaction sites, and enhanced O 2 adsorption. CDs act as “bridges” for electron transmission and regulate the surface hydrophobicity of CMP, further improving charge transfer and optimizing the reaction interface. CDs/CMP system exhibits a high H 2 O 2 production of 8542.6 µmol g −1 h −1 and concurrent furoic acid production at 2.22 m m h −1 . This H 2 O 2 production rate is ≈90% higher than that in the diphase system, exceeding all previously reported photocatalysts in triphase systems. Notably, the CDs/CMP system achieves the relative separation of the photocatalysts and H 2 O 2 , suppressing the generated H 2 O 2 self‐decomposition. Theoretical calculations and in situ characterizations reveal the mechanism of H 2 O 2 and furoic acid evolution. This self‐floating system provides insights into exploring the application of metal‐free photocatalysts in heterogeneous reactions.