The recent COVID-19 pandemic has resulted in the massive discard of pandemic-related plastic wastes, causing serious ecological harm and a high societal burden. Most single-use face masks are made of synthetic plastics, thus their careless disposal poses a direct threat to wildlife as well as potential ecotoxicological effects in the form of microplastics. Here, we introduce a 1D magnetic photoactive microswarm capable of actively navigating, adhering to, and accelerating the degradation of the polypropylene microfiber of COVID-19 face masks. 1D microrobots comprise an anisotropic magnetic core (Fe3O4) and photocatalytic shell (Bi2O3/Ag), which enable wireless magnetic maneuvering and visible-light photocatalysis. The actuation of a programmed rotating magnetic field triggers a fish schooling-like 1D microswarm that allows active interfacial interactions with the microfiber network. The follow-up light illumination accelerates the disruption of the polypropylene microfiber through the photo-oxidative process as corroborated by morphological, compositional, and structural analyses. The active magnetic photocatalyst microswarm suggests an intriguing microrobotic solution to treat various plastic wastes and other environmental pollutants.

Center for Advanced Functional Nanorobots Department of Inorganic Chemistry Faculty of Chemical Technology University of Chemistry and Technology Prague Technická 5 166 28 Prague Czech Republic

Department of Chemical and Biomolecular Engineering Yonsei University 50 Yonsei ro Seodaemun gu Seoul 03722 Korea

Department of Medical Research China Medical University Hospital China Medical University No 91 Hsueh Shih Road Taichung 40402 Taiwan

Faculty of Electrical Engineering and Computer Science VSB Technical University of Ostrava 17 listopadu 2172 15 708 00 Ostrava Czech Republic

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