A novel solid–liquid route for the preparation of Cu3Se2 and Ag2Se nanocrystals

Cu3Se2 and Ag2Se nanocrystals have been synthesized with Se as the precursor in aqueous solutions under photo-irradiation at room temperature. The obtained products were analyzed through X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The results showed that the tetragonal phase of Cu3Se2 with nearly spherical grains and the orthorhombic phase of Ag2Se with nanoscale dendrite were formed. The experiments also confirmed that photo-irradiation and Na2SO3 played important roles in the formation of Cu3Se2 and Ag2Se nanocrystals. The formation mechanism of Cu3Se2 and Ag2Se nanocrystals was investigated in detail.