Enhanced Dual-Pathway Photocatalytic Hydrogen Peroxide Production Enabled by Plastic-Derived Mixed-Linker UiO-66-NH2

Photocatalytic hydrogen peroxide (H 2 O 2 ) production using metal-organic frameworks (MOFs) offers a sustainable alternative to the energy-intensive anthraquinone process. However, conventional single-linker MOFs are limited by ineffective charge separation and insufficient oxygen activation sites. Herein, polyethylene terephthalate (PET) was upcycled into mixed-linker UiO-66-NH 2 by a rapid room-temperature aqueous synthesis. Introducing 2-amino-terephthalic acid (NH 2 -BDC) into PET-derived UiO-66 tuned the defect environment, electronic structure, and photocatalytic activity. The optimized PET-UiO-66-NH 2 -50% achieved an efficient H 2 O 2 production rate of 488 μmol g -1 h -1 and a concentration of 1500 μmol L -1 in pure water after 3 h visible-light irradiation, significantly outperforming PET-UiO-66 and PET-UiO-66-NH 2 -100%. Atmosphere-dependent experiments reveal contributions from both oxygen reduction (ORR) and water oxidation (WOR). Rotating ring-disk electrode tests showed up to 90% H 2 O 2 selectivity with an electron transfer number close to 2, supporting a selective two-electron ORR pathway. In situ attenuated total reflectance infrared (ATR-IR) spectroscopy detected hydroperoxo-related intermediates under light irradiation, confirming their key role in both ORR and WOR. The generated H 2 O 2 solution was further applied to practical swimming pool water treatment and reduced swimming-pool-water turbidity without appreciably altering pH or alkalinity. This work provides a sustainable strategy for simultaneously upcycling plastic waste and producing green H 2 O 2 .