Flask-like Janus Colloidal Motors with Explicit Direction and Tunable Speed.

Nanoparticles with an anisotropic morphology and composition are flourishing in various scientific fields. Their morphology has a great impact on their functions, but the precise regulation of their growth and final morphology is still challenging. Here, flask-like Janus particles (FJPs) with different compositions segmented on the inner and outer surfaces were fabricated via a sol-gel process using different silane precursors. The neck length of the flask-like particles can be controllably regulated by employing different silane precursors. The Pt catalyst was selectively loaded in their cavities, and as-formed FJPs@Pt are employed as colloidal motors. Due to the adjustable neck length, the Janus colloidal motors have explicit directionality and tunable speeds (max diffusion coefficient is 18.2 µm2 s-1).

Tadpole-like Janus nanotubes.

Tadpole-like Janus nanotubes with controlled size are fabricated by a sol-gel reaction at the emulsion interface. Pd or Fe3O4 nanoparticles can be selectively captured into their cavities to obtain tadpole-like Janus Pd-nanotubes or tadpole-like Janus Fe3O4-nanotubes. They can be driven directionally by a chemical fuel or near-infrared (NIR) light.