Efficient Oxygen-Accelerated Near-Infrared Photoinduced Atom Transfer Radical Polymerization Mediated with S-Scheme Heterojunction Photocatalyst Composed of Lead-Free Halide Perovskite Encapsulated into Metal–Organic Framework

Abstract

All-inorganic lead-free halide perovskite Cs₃Bi₂I₉ was encapsulated in a zirconium-porphyrin metal–organic framework (MOF-545) to create a S-scheme heterojunction photocatalyst Cs₃Bi₂I₉@MOF-545 for efficient copper-mediated photoinduced atom transfer radical polymerization (photo-ATRP). The close interfacial contact and the disparity in the work function between MOF-545 and Cs₃Bi₂I₉ has been demonstrated to facilitate photoinduced charge transfer at the interface and boost the efficiency of photogenerated charge separation and utilization. The distinctive advantage of S-scheme charge transfer enabled the optimized Cs₃Bi₂I₉@MOF-545 to effectively regulate the Cu-mediated photo-ATRP of diverse monomers under 850 nm near-infrared (NIR) light with good terminal fidelity, even achieving high monomer conversion on the barriers of 5 mm PP board and 4 mm pigskin. In a large reaction volume (250 mL), the monomer conversion reached approximately 99% with a first-order kinetic behavior under 850 nm NIR light, demonstrating potential for industrial applications. High photocatalytic activity was maintained after 10 cycles of use in organic solvent (DMSO) or 6 days of water immersion. Furthermore, it is unveiled that the limited oxygen can enhance trithanolamine (TEOA) oxidation to accelerate Cu-mediated photo-ATRP in heterojunction photocatalysts for the first time. This study offers insights into designing MOF-based photocatalysts to augment Cu-mediated photo-ATRP performance under NIR-light.