Synthesis of hollow lead sulfide microspheres

Lead sulfide (PbS) uniform hollow spheres have been successfully synthesized by γ-irradiating PMMA-CS2-ethanol aqueous solution that contains Pb(CH3COO)2·3H2O at room temperature. X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron micrograph (TEM), and high-resolution transmission electron micrograph (HRTEM) experimental results show that the diameter of PbS hollow spheres, the thickness of sphere shell, and the size of these crystallites are about 500, 20, and 10 nm, respectively. Room temperature UV-vis absorption spectrum of the PbS hollow spheres gives its peak centered at around 238 nm and a weak shoulder peak centered at about 322 nm. The obvious blue shift of the absorption peak may be attributed to the small dimension of the PbS bricks of the spheres wall. A possible growth mechanism of PbS hollow sphere is also presented. The successful preparation of PbS hollow spheres in large scale under mild conditions could be of interest for both applications and fundamental studies.