Dual Single Atoms Boosting Photocatalytic Upcycling of Raw Polyvinylidene Fluoride Plastic.

Abstract

Polyvinylidene fluoride (PVDF) is a highly recalcitrant fluorinated polymer that is highly resistant to chemical degradation, making its sustainable recycling and upcycling challenging. Despite its widespread use as a binder in the lithium-ion battery industry, effective strategies for converting PVDF waste into value-added chemicals remain limited. To resolve this, Fe and Cu dual single atoms incorporated on a new two-dimensional material nanosheets (In2P3S9 NSs/Fe-Cu DSAs) were prepared as photocatalysts for direct raw PVDF plastic conversion to high-value chemicals. The best-performing photocatalyst (Fe1.0Cu0.5) achieves a total acetic/formic acid generation of ∼1351.8 µmol g-1. Various in situ characterizations such as atomic force microscopy-kelvin probe force microscopy, x-ray photoelectron spectroscopy, and electron paramagnetic resonance (EPR) demonstrate superior electron extraction from In2P3S9 NSs to Fe and Cu DSAs, after which the electrons are subsequently scavenged by O2 under ambient conditions. Moreover, quenching experiments as well as in situ infrared spectroscopy, and in situ EPR reveal the vital impact of photoexcited electrons and hydroxyl radicals in PVDF upcycling into high-value products. These findings highlight the significant potential of photocatalysis in transforming one of the most resistant plastic wastes (PVDF) into value-added products, providing a sustainable remedy for plastic pollution crisis.