Tandem Photocatalytic H₂O₂ Production and In Situ Upgrading Enabled by Docking and Locking Engineered Covalent...

Photocatalytic H₂O₂ generation is hindered by low concentrations and energy-intensive purification, posing major barriers to practical application. Herein, a tandem catalytic strategy that integrates H₂O₂ generation with its in situ utilization in organic synthesis is reported to overcome these constraints. Covalent organic frameworks (COFs) engineered through a "docking and locking" strategy provide an ideal platform for enabling such tandem transformations. The optimized TTPh-OH COF delivers benchmark H₂O₂ production rates of 11.42 mmol g^-1 h^-1 in pure water and 61.96 mmol g^-1 h^-1 in isopropanol/water (9:1 v/v). Leveraging the high efficiency, a single-photocatalyst tandem platform generates 22.1 mM H₂O₂, which is subsequently consumed to drive the hydrobromination of 4-methylstyrene with 99% conversion and 87% selectivity, demonstrating the practical utility of in situ photocatalytic H₂O₂. This integrated approach outlines a blueprint for circular, solar-driven photoredox catalysis that upgrades O₂ and H₂O into value-added organic products.