Five-Fold Twinned Pd Nanorods and Their Use as Templates for the Synthesis of Bimetallic or Hollow Nanostructures

We report the use of seed-mediated growth for the facile synthesis of five-fold twinned Pd nanorods with controlled diameters in the range of 6–16 nm and tunable lengths up to 81 nm. In this approach, the formation of decahedral seeds and their anisotropic growth could be deliberately performed under different conditions to obtain samples with high purity. Transmission electron microscopy studies revealed that the nanorods were formed through the deposition of Pd atoms onto the surfaces of decahedral seeds along the <110> direction. Subsequent mechanistic studies indicated that a combination of a proper reduction rate and an effective capping agent was crucial to the formation of Pd nanorods. With the use of these Pd nanorods as templates, we also demonstrated the synthesis of Pd–Pt bimetallic nanotubes, as well as Pd@Au and Pd@Ag core–sheath nanorods.