Facile Fabrication of Bubble-Propelled Micromotors Carrying Nanocatalysts for Water Remediation

A facile and flexible approach is developed to fabricate bubble-propelled mesoporous micromotors carrying nanocatalysts for efficient water remediation. The micromotors are prepared by simply coating the hemispherical surface of Fe₃O₄-nanoparticle-containing mesoporous SiO₂ microparticles with a polydopamine layer for decorating Ag nanoparticles, based on the versatile adhesion and reduction properties of polydopamine. The Fe₃O₄ nanoparticles can produce OH radicals from H₂O₂ for pollutant degradation via Fenton reaction, whereas the mesoporous SiO₂ matrix provides large surface area with anchored Fe₃O₄ nanoparticles for improved degradation performance. Moreover, the Ag nanoparticles can decompose H₂O₂ into oxygen bubbles for powering the movement of micromotors to further enhance the pollutant degradation. The micromotors that synergistically integrate these functions enable efficient degradation of pollutants, such as methylene blue demonstrated in this work, for water remediation. This approach offers a simple and versatile strategy for creating micromotors with flexible compositions and structures for applications in water remediation, drug delivery, and cargo transport.