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.