Surface synthesis of PbS nanoparticles on silica spheres by a sonochemical approach

A simple sonochemical approach for the preparation of PbS nanoparticles homogeneously coated on sub-micrometer silica spheres has been described. The transmission electron microscopy and scanning electron microscopy images show that the PbS nanoparticles with size of 30 nm were coated on the silica spheres, without any free nanoparticles. X-ray diffraction reveals that the PbS nanoparticles are of cubic rock-salt structure. Moreover, by dissolving the silica cores with a diluted hydrofluoric acid solution, stable PbS hollow structures were obtained. It is considered that the sonochemical process in which triethanolamine acted as complex agent played an important role for the homogenouse coating of PbS nanoparticles on silica spheres.