Seeded Growth of Au@PdAg Alloy Core‐Shell Nano‐Dendrites with Tunable Size and Composition.

We report a facile synthesis of Au@PdAg alloy core‐shell nanocrystals in dendrite form, having tunable size and composition. In particular, using spherical Au nanoparticles as seeds, the co‐reduction of Pd and Ag precursor in growth stage results in the formation of PdAg alloy shells with a dendrite shape. Their size and elemental composition can be tuned by varying the seed amount and feeding ratio in Pd and Ag precursor, respectively, illustrating the versatility of the current synthetic strategy. The size, morphology, and elemental composition of the products have been characterized using a set of techniques, including SEM, TEM, XRD, XPS, HAADF‐STEM, and EDX‐STEM mapping. When working as electrocatalysts, the current Au@PdAg alloy core‐shell nanocrystals supported by carbon black exhibit enhanced activity and excellent operation stability for electroxidation of ethanol as compared to commercial Pd/C. The current work offers a feasible strategy to preparation of multi‐metallic core‐shell dendritic nanocrystals with controllable size and composition and could find important use in fuel cells and related fields. [ABSTRACT FROM AUTHOR]