Synthesis of Pd@Rh nanocubes with well-defined {100} surface and controlled shell thicknesses for the fabrication of Rh nanocages

We report a facile synthesis of Pd@Rh core-shell nanocubes with ultrathin Rh shell and well-defined, smooth {100} facets for the production of Rh cubic nanocages. Under carefully optimized conditions, the deposition and diffusion rates of Rh adatoms on Pd cubic seeds can be tuned to a suitable level to enable the layer-by-layer growth of Rh overlayers. Specifically, the reaction temperature, type of Rh precursor, injection rate of the precursor solution, in addition to the size of the Pd seeds, all play an important role in establishing the desired growth mode while preventing island growth and homogeneous nucleation. The Rh shell not only endows the nanocrystals with significantly enhanced shape stability against thermally activated transformation under heating up to 500 degrees C, but also enables the production of Rh nanocages with ultrathin walls and well-preserved {100} facets, which to our knowledge has not been reported in literature.

Automated summary

We report a simple method to synthesize Pd@Rh core-shell nanocubes with ultrathin Rh shell and well-defined {100} facets for the production of Rh cubic nanocages. The growth of Rh overlayers on Pd cubic seeds can be controlled by adjusting the deposition and diffusion rates of Rh adatoms. The resulting Rh nanocages exhibit enhanced shape stability and ultrathin walls with preserved {100} facets, which has not been reported previously.