Octopods versus concave nanocrystals: control of morphology by manipulating the kinetics of seeded growth via co-reduction.

Au/Pd octopods and concave core@shell Au@Pd nanocrystals have been prepared by coupling for the first time a seed-mediated synthetic method with co-reduction. The integration of these two methods is central to the formation of these binary Au/Pd nanocrystals wherein the kinetics of seeded growth are manipulated via the co-reduction technique to control the final morphology of the nanocrystals. Significantly, the synthesis of these structures under similar reaction conditions illustrates that they are structurally related kinetic products. Detailed characterization by STEM-EDX analysis highlights the unique structural features of these nanocrystals and indicates that Pd localizes on the higher-energy features of the nanocrystals. Optical and electrocatalytic characterization also demonstrates their promise as a new class of multifunctional nanostructures.