Sonochemical synthesis and mechanistic study of copper selenides Cu2-xSe, β-CuSe, and Cu3Se2

Nanocrystallites of nonstoichiometric copper selenide (Cu2-xSe) and stoichiometric copper selenides (beta-CuSe and Cu3Se2) were synthesized in different solutions via sonochemical irradiation at room temperature. The influence of solvents, surfactants, and ultrasonic irradiation on the morphology and phase of products has been investigated. The morphological difference of the products was mainly affected by the solvents and surfactants, which can self-aggregate into lamellar structures or microemulsions, and then these unique structures can act as both supramolecular template and microreactor to direct the growth of copper selenides. On the other hand, it was also found that the sonochemical irradiation and solvents played an important role in the formation of different phases of copper selenides. The proposed formation mechanism of copper selenides is discussed.