Encapsulation of carbon-nanodots into metal-organic frameworks for boosting photocatalytic upcycling of polyvinyl chloride plastic
Jibo Qin, Yibo Dou, Jianchi Zhou, Dan Zhao, Tobias Orlander, Henrik Rasmus Andersen, Claus Hélix‐Nielsen, Wenjing Zhang
Abstract
Although polyvinyl chloride (PVC) ranks as the third most mass-produced synthetic plastic, the chemical upcycling of non-biodegradable PVC waste remains a significant challenge. Herein, carbon nanodots combined with the metal-organic framework (CDs/Zr-MOF) are fabricated for photocatalytic upcycling of PVC. Specifically, the ultra-small-sized CDs (~2.0 nm) are encapsulated into Zr-MOF pores via a mild pyrolysis strategy. The maintained MOF structure facilitates charge/mass transfer and improves the surface-to-volume ratio of active sites of CDs. The CDs/Zr-MOF exhibits high activity for PVC conversion of ~76.5% towards acetic acid with a yield of ~14%. The mechanism investigation indicates the generated •OH radicals can efficiently trigger cleavage of C-Cl/C-C bonds of PVC. Moreover, the reduction of the energy barrier for the hydroxylation reaction as a rate-limiting step contributed to improved PVC conversion performance. This work offers a feasible method for fabricating nanoparticle-embedded MOF-based photocatalysts and provides new insights into the chemical upcycling of plastics.