Synthesis of cubic Pd–Ag random alloy nanocrystal in an aqueous solution in the presence of CTAB

When a mixture of H2PdCl4 and AgNO3 was co-reduced by ascorbic acid in aqueous solution in the presence of CTAB as a surfactant, aside from irregular shapes of Pd–Ag alloy particles, new cubic Pd–Ag alloy nanocrystals were prepared. The transmission electron microscopic (TEM)–energy dispersed X-ray spectroscopic (EDS) data at the atomic level suggest that Pd–Ag cubic alloys surrounded by {100} facets consist of substitutional solid solution and the arrangement of the solute Ag atoms is random. The Ag atomic content in Pd–Ag alloy must be less than ≈22% for preservation of the cubic structure. Optical properties of Pd–Ag alloys were characterized by observing the extinction spectra in the ultraviolet(UV)–visible(vis) range.

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► New Pd rich Pd–Ag cubic alloy nanocrystals were produced from an aqueous solution of H2PdCl4/AgNO3/CTAB/ascorbic acid.
► Atomic-level TEM–EDS data suggest that Pd–Ag cubic alloys surrounded by {100} facets consist of a substitutional solid solution and that the arrangement of the solute Ag atoms is random.
► The Ag atomic content in Pd–Ag alloy must be less than ≈22% for preservation of the cubic structure.