Controlled one-sided growth of Janus TiO₂/MnO₂ nanomotors

Designing and building new micro/nanomotors are among the most exciting challenges facing nanotechnology. Considering the expensive equipment and the high cost associated with noble metals, a scalable and reliable fabrication method is desired for the fabrication of Janus particles. In this work, we report on the preparation and characterization of self-propelled micromotors based on Janus TiO₂/MnO₂ nanoparticles. The Janus micromotor is constructed by growing propulsion material MnO₂ nanoflakes in situ on one hemisphere of TiO₂ by photoreduction of KMnO₄ under aerobic conditions. The MnO₂ nanoflakes can catalytically decompose hydrogen peroxide fuel to generate oxygen bubbles, which consequently repel the micromotors forward in the solution. Thus, the Janus TiO₂/MnO₂ nanoparticle represents a promising material for the preparation of micromotors for various biomedical or environmental applications. (paper)