Carbon quantum dot boots the photocatalytic overall hydrogen peroxide production on triazine-based covalent organic framework

Photocatalytic overall H₂O₂ production shows significances in green manufactory through converting solar energy into valuable chemicals under nature H₂O and O₂. Covalent organic frameworks (COFs) hold promises in photocatalysis but still face challenges in bandgap regulation for dual-pathway of simultaneous two-electron oxygen reduction (2e⁻ ORR) and water oxidation (2e⁻ WOR). Here, we report an S-scheme heterojunction catalyst (CQDs@COF) constructed by integrating carbon quantum dots (CQDs) into triazine-ureidoimine-based TP-COF. The CQDs enhance visible-light absorption, narrow the bandgap, and improve hydrophilicity/O₂ affinity, synergistically boosting H₂O₂ generation. DFT calculations and controlled experiments elucidated the electron transfer pathway from CQDs to TP-COF via the S-scheme heterojunction, enabling a successful overall H₂O₂ production. Remarkably, [email protected] achieved an exceptional H₂O₂ yield of 1062 μmol g⁻¹ within 60 min under ambient conditions using pure water without any sacrificial agents. This work offers a novel strategy to enhance charge separation/migration in COFs for efficient photocatalysis, advancing the rational design of high-performance photocatalytic systems.