Janus particles with tunable coverage of zinc oxide nanowires

We demonstrated the first example of Janus microspheres with ZnO nanowires. A method for electrochemical growth of ZnO nanowires on partially masked microspheres was adopted in the Janus particle synthesis. The coverage area of ZnO nanowires on the polystyrene or SiO2 microspheres can be tailored by varying the masking layer thickness. The pretreatment of microspheres with Zn2+ could effectively improve the growth of ZnO nanowires on the microspheres. The conductivity of the masking polymer is also an important factor for obtaining uniformly distributed ZnO nanowires on the microspheres.