Controlled synthesis of cuprous oxide nanospheres and copper sulfide hollow nanospheres

Uniform Cu2O nanospheres have been successfully synthesized by reducing CuSO4 with ascorbic acid in sucrose solution at room temperature. The diameter of the Cu2O nanospheres can be tuned from 90 to 280 nm by adding different amounts of sucrose in the solution. Furthermore, CuS hollow nanospheres with different diameters have been obtained based on the Kirkendall effect using the as-prepared Cu2O nanospheres as sacrificial templates. Cu2O/Cu7.2S4 core/shell nanospheres and Cu7.2S4 hollow nanospheres are obtained as the intermediate products at different stages of the conversion process. Through the post-treatment of sodium citrate solution, Cu7.2S4 hollow nanospheres can be changed into CuS hollow nanospheres. The products are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and field-emission scanning electron microscopy (FESEM). Optical properties of the products have also been studied.