Bio-Templated Fabrication of Distinctive ZIF-67-Based Self-Propelled Micromotors for Dynamically Removing Antibiotics from Aqueous Media

Due to their autonomous and controllable motions, micromotors show excellent potential for practical application to environmental remediation. We used natural pine pollens (PPs) as bio-templates (ZIF-67@PP) to develop distinctive “Mickey Mouse”-shaped ZIF-67-nanoparticle (NP)-based bubble-mediated self-propelled micromotors for dynamically degrading tetracyclines (TCs) in water. The as-prepared micromotors possessed a unique core–shell structure comprising a PP core and a ZIF-67 NP shell and were effectively self-propelled by oxygen ( O 2 ) bubbles generated by the ZIF-67-catalyzed decomposition of hydrogen peroxide ( H 2 O 2 ) . Additionally, the ZIF-67@PP micromotors’ velocity was further enhanced by optimizing the ZIF-67 NP loading and H 2 O 2 concentration. Meanwhile, the outer ZIF-67 NP shell effectively adsorbed and degraded TCs, enhancing the TC degradation efficiency of the dynamic micromotors by approximately 2.7 times compared to that of the static nonmicromotor counterpart, mainly because of the synergy of the enhanced self-motion-mediated localized mixing and outstanding adsorption and catalytic oxidation of ZIF-67 NPs. After the systematic optimization of the treatment conditions, an initial ZIF-67@PP micromotor concentration of 2 0 mg ⋅ L − 1 degraded more than 90% of the TCs within 10 min. Furthermore, the introduction of magnetic Fe 3 O 4 NPs enabled the remote magnetic control of the movement direction and magnetic recycling of the micromotors. Our work not only offers a facile strategy to incorporate a versatile family of metal–organic frameworks into the design of bubble-mediated self-propelled micromotors but also demonstrates the practical application potential of micromotors possessing distinctive morphologies for removing antibiotics from aquatic ecosystems.