Janus nanorods with tailored size and tip shape

Polystyrene-Gold (PS-Au) Janus and Polystyrene-Silver/Silver Chloride (PS-Ag/AgCl) nanomotors (Fig.1) with aspect ratios (length divided by width) ranging from 10 to 15 have been prepared by template based synthesis using anodic aluminium oxide (AAO) followed by replication methods presented in this work. The wettability transition from wetting to nonwetting of PS inside the cylindrical pores of AAO template in nonsolvent polyethylene glycol was used to manipulate the morphology of PS nanorods. To generate anisotropy in surface chemistry of nanorods, we deposited 15 nm Au or 30 nm Ag layers running along the minor axis. The trajectories of the Janus nanorods were captured by mean of video microscopy and analyzed in term of the MSD and MSAD. The fabricated PS-Au Janus nanoparticles showed the efficient decomposition of hydrogen peroxide even at very low concentrations ranging from 0.1% to 0.4%. For the PS-Ag/AgCl Janus nanorods exposed to blue light, the generation of the local chemical gradient led to changes in rotational behavior of single nanorods.