Magnetically Driven Photo‐Microswarms Enable Efficient Polypropylene Fiber Fragmentation and Sterilization

Abstract

ABSTRACT The extensive utilization and inadequate handling of personal protective equipment waste have emerged as important contributors to microplastic contamination worldwide. Consequently, there is a growing demand for advanced and efficient remediation technologies. This study presents the development of a magnetically boosted photoactive BiOCl/BiOI/Fe 3 O 4 (BBF) micromotor for active navigation, attachment, and accelerated degradation of polypropylene (PP) microfibers derived from medical masks. By integrating a visible‐light‐responsive BiOCl/BiOI heterojunction with superparamagnetic Fe 3 O 4 , the micromotor not only exhibits excellent photocatalytic activity for generating reactive oxygen species but also achieves controlled locomotion and collective “schooling‐like” behavior under a programmed rotating magnetic field. Results indicate that the magnetic enhancement significantly improves the attachment capability and interfacial interaction of the micromotor within PP microfiber networks. Subsequent light irradiation not only promotes autonomous attachment of the micromotor to the fibers but also generates concentrated oxidants that accelerate the degradation of PP films. After 30 h of solar irradiation, a marked increase in oxidative functional groups and formation of holes were observed in the PP microfibers, confirming enhanced photo‐oxidative degradation. Furthermore, the micromotor demonstrates excellent antibacterial performance under visible light and allows for magnetic recovery, offering a promising microrobotic solution for addressing aquatic microfiber pollution and fibrous plastic waste.