Tuning the morphology of gold nanocrystals by switching the growth of {110} facets from restriction to preference

Single crystalline Au nanorods (Au NRs), synthesized via seed-mediated growth, show unique surface structures. Apart from the oft-observed {100} and {111} facets, unexpectedly, unstable {110} facets dominate in such nanorods due to {110} restricted growth. Unique properties have been suggested for the nanorods. One novel property, we believe, is that the the high-energy {110} endows the nanorod with a high reactivity, thus making the growth to more stable morphologies possible. Herein, by switching the growth to the {110} preference, we successfully obtained thermodynamically more, stable morphologies (arrow-headed gold nanorods and gold nano-octahedra) with a high quality and yield. A blockade of selective underpotential deposition of silver is suggested to be responsible for the switching.