Enhancing Microplastic Degradation through Synergistic Photocatalytic and Pretreatment Approaches

Area of Science:

• Environmental Science
• Materials Science
• Chemistry

Background:

• Microplastic (MP) pollution is a significant global environmental issue.
• Conventional remediation methods are insufficient for small-dimension MPs.
• Poly(ethylene terephthalate) (PET) is a common plastic pollutant.

Purpose of the Study:

• To develop an effective method for degrading poly(ethylene terephthalate) microplastics (PET MPs).
• To investigate the synergistic effect of hydrothermal pretreatment and BiOCl photocatalysis for MP degradation.
• To elucidate the mechanism behind enhanced PET MP degradation.

Main Methods:

• Synthesis of spherical (BOC-S) and nanosheet (BOC-N) BiOCl photocatalysts.
• Hydrothermal pretreatment of PET MPs.
• Photocatalytic degradation experiments using BOC-S and BOC-N with and without pretreatment.
• Free radical trapping experiments to identify active species.

Main Results:

• Pretreated PET MPs showed 8.8 (BOC-S) and 6.9 (BOC-N) times higher degradation efficiency compared to unpretreated MPs.
• Pretreatment enhanced PET MP surface porosity, hydrophilicity, and specific surface area.
• Hydroxyl radicals (·OH) were identified as the primary active species responsible for degradation.

Conclusions:

• The combined hydrothermal pretreatment and BiOCl photocatalysis system offers a highly effective approach for PET MP degradation.
• Surface modification of MPs is crucial for enhancing photocatalytic degradation efficiency.
• This research provides a novel strategy for microplastic remediation.