Abstract

Self-motile mesoporous ZnO/Pt-based Janus micromotors accelerated by bubble propulsion that provide efficient removal of explosives and dye pollutants via photodegradation under visible light are presented. Decomposition of H2O2 (the fuel) is triggered by a platinum catalytic layer asymmetrically deposited on the nanosheets of the hierarchical and mesoporous ZnO microparticles. The size-dependent motion behavior of the mesoporous micromotors is studied; the micromotors with average size ∼1.5 μm exhibit enhanced self-diffusiophoretic motion, whereas the fast bubble propulsion is detected for micromotors larger than 5 μm. The bubble-propelled mesoporous ZnO/Pt Janus micromotors show remarkable speeds of over 350 μm s-1 at H2O2 concentrations lower than 5 wt %, which is unusual for Janus micromotors based on dense materials such as ZnO. This high speed is related to efficient bubble nucleation, pinning, and growth due to the highly active and rough surface area of these micromotors, whereas the ZnO/Pt particles with a smooth surface and low surface area are motionless. We discovered new atomic interfaces of ZnO2 introduced into the ZnO/Pt micromotor system, as revealed by X-ray diffraction (XRD), which contribute to enhance their photocatalytic activity under visible light. Such coupling of the rapid movement with the high catalytic performance of ZnO/Pt Janus micromotors provides efficient removal of nitroaromatic explosives and dye pollutants from contaminated water under visible light without the need for UV irradiation. This paves the way for real-world environmental remediation efforts using microrobots.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.