Development of Economic Benzyl Alcohol-Based Polymers for Full Reaction Photocatalytic Hydrogen Peroxide Production

Porous organic polymers (POPs) have received extensive attention in photocatalytic hydrogen peroxide (H2O2) production. Nonetheless, the main factors contributing to the arrival at practical application are the synthesis complexity, catalytic efficiency, operational stability, synthetic cost, and the long-overlooked water oxidation reaction (WOR). Herein, a series of metal-free photocatalysts were synthesized via a one-step Friedel–Crafts reaction using the inexpensive monomers 1,4-benzenedimethanol and 4,4′-bis(chloromethyl)-1,1′-biphenyl, with a cost of 0.084 $ g–1. Importantly, band structure engineering enables concurrent oxygen reduction reaction and WOR activation, achieving a record productivity of 3.94 mmol g–1 h–1 under air. To facilitate economic scalability and reproducibility, a dual-liquid-phase cyclic system for continuous H2O2 production was equipped to deliver H2O2 in a controllable concentration, highlighting its practical application. This work advances the fundamental understanding of structure–activity correlations in heterogeneous photocatalysis while delivering an engineered solution for sustainable and cost-effective H2O2 synthesis, bridging molecular-level design with scalable applications.