Self-assembly of ZnO nanoparticles and subsequent formation of hollow microspheres

Nanostructure ZnO hollow microspheres with average crystallite size of about 15 nm, and average diameter of about 1 μm, were successfully fabricated through a novel hydrothermal method. Hollow microspheres were formed due to self-assembly of ZnO oblong nanoparticles, which resulted in formation of a protrusive surface nanostructure. The obtained material was characterized with X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) investigations. The photoluminescence characterization of the nanostructure microspheres exhibited a UV irradiation at around 380 nm and a broad visible emission band centered at green region.