Harnessing efficient in-situ H2O2 production via a KPF6/BiOBr photocatalyst for the degradation of polyethylene

Abstract

• KPF 6 doped BiOBr were successfully synthesized using a simple one-pot hydrothermal method. • The photocatalytic H 2 O 2 production of 20 wt% KPF 6 /BiOBr is 1.96 times higher than pure BiOBr. • Plastic bags were decomposed by KPF 6 /BiOBr in conjunction with the in-situ generation of H 2 O 2 . • Hydroxyl radicals play a key role in the polyethylene degradation. • A potential mechanism for H 2 O 2 production and polyethylene degradation was proposed. The development of cost-effective dual-function photocatalytic materials to advance clean energy generation and storage combined with superior pollutant degradation performance has thus far remained challenging. For this study, potassium hexafluorophosphate (KPF 6 ) was introduced to modify BiOBr via a simple one-pot hydrothermal method, where uniformly dispersed KPF 6 on BiOBr nanosheets improved H 2 O 2 yields and the pollutant degradation performance. Such materials have proven to be critical for low bandgap and enhanced surface charge separation for efficient H 2 O 2 production. The optimized sample of 20 wt% KPF 6 /BiOBr showed a H 2 O 2 production rate of 53.36 mg·L –1 , which was much higher than that of pure BiOBr (27.19 mg·L –1 ). Nitroblue tetrazolium chloride (NBT) superoxide radical detection results suggested that two-step single-electron oxygen reduction was the primary pathway. More importantly, discarded polyethylene bags from supermarkets have been decomposed though the in-situ generation of H 2 O 2 using KPF 6 /BiOBr materials, and the mass loss of plastics was 2.33 times higher than that of the pure BiOBr. This research offers new perspectives toward the development of new functionalized materials for H 2 O 2 production, while improving capacities for the degradation of plastics.