Room-temperature synthesis of copper and silver, nanocrystalline chalcogenides in mixed solvents

Copper and silver nanocrystalline chalcogenides, Cu_2-xSe, Cu₂Te, Ag₂Se, and Ag₂Te, have been successfully synthesized in a mixture of ethylenediamine and hydrazine hydrate as a solvent at room temperature. Products showed different morphologies, such as nanotubes, nanorods, and nanoparticles. The results indicated that the coordination and chelation abilities of ethylenediamine play an important role in the formation of one-dimensional nanocrystalline binary chalcogenides, and hydrazine hydrate is crucial to the electron transfer in the room temperature reactions. These transition-metal nanocrystalline chalcogenides as prepared were analyzed by X-ray powder diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The UV-Vis absorption properties of these nanocrystals were also measured.