Zerovalent-Iron/Platinum Janus Micromotors with Spatially Separated Functionalities for Efficient Water Decontamination

Multifunctional zerovalent-iron/platinum (ZVI/Pt) Janus bubble-propelled micromotors with high decontamination efficiency and efficient self-propulsion properties were fabricated by the asymmetric deposition of catalytic platinum (Pt) in one hemisphere of ZVI microspheres. In the ZVI/Pt micromotors–hydrogen peroxide (H2O2) system, ZVI acts as a heterogeneous Fenton-like catalyst for the degradation of organic pollutants, while simultaneously the hemispheric Pt layer catalytically decomposes H2O2 into water and oxygen, thereby resulting in an oxygen-bubble propulsion system. The ZVI/Pt Janus micromotors were bubble-propelled at a high speed of over 200 μm/s in the presence of 5% H2O2. In addition, complete oxidative degradation of methylene blue (MB) occurred in the presence of 5% H2O2 after 60 min of treatment, whereas ZVI microspheres removed only 12% of MB in 60 min. The magnetic controllable and reusable properties of the ZVI/Pt micromotors make the water purification process more attractive and feasible. Therefore, the application of ZVI with unique redox chemistry to a micromotor system could hold great promise for the development of innovative water purification and remediation technologies in the future.