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

Photocatalytic oxygen (O2) reduction to hydrogen peroxide (H2O2) 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 O2, and the self-decomposition of H2O2 in traditional diphase systems. Here, a self-floating carbon dots/conjugated microporous polymer (CDs/CMP) photocatalytic system is established for H2O2 production and organic synthesis. Due to the D-pi-A structure, porous structure, and hydrophobicity, CMP induced the intramolecular charge transfer, exposed abundant reaction sites, and enhanced O2 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 H2O2 production of 8542.6 mu mol g-1 h-1 and concurrent furoic acid production at 2.22 mm h-1. This H2O2 production rate is approximate to 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 H2O2, suppressing the generated H2O2 self-decomposition. Theoretical calculations and in situ characterizations reveal the mechanism of H2O2 and furoic acid evolution. This self-floating system provides insights into exploring the application of metal-free photocatalysts in heterogeneous reactions. A self-floating carbon dots/conjugated microporous polymer (CDs/CMP) system is developed for photocatalytic hydrogen peroxide (H2O2) production and organic synthesis. Benefiting from unique porous structure, efficient charge transfer and optimized reaction interface, CDs/CMP system exhibited a high H2O2 (8542.6 mu mol g-1 h-1) and concurrent furoic acid (2.22 mm h-1) production, which provides a reference for designing metal-free photocatalysts for heterogeneous reactions. image