Au@Pd core–shell nanocubes with finely-controlled sizes

We report a facile method for the synthesis of highly uniform Au@Pd core–shell nanocubes with finely- and well-controlled sizes by seed-mediated growth. Using single-crystal seeds of Au spheres with a uniform size, we could reproducibly obtain Au@Pd core–shell nanocubes with a narrow size distribution (<7% in standard deviation) and in high yield (>98%). Moreover, the size of the Au@Pd core–shell nanocubes could be finely and readily tuned in a controllable fashion from 11.4 to 41.1 nm in edge length by varying the concentration of Na2PdCl4, the amount of seeds, or both. We have also investigated the localized surface plasmon resonance properties of Au@Pd core–shell nanocubes as a function of Pd shell thickness.