Urchin-like ZnO nanostructures: Synthesis, characterization and optical properties

Urchin-like ZnO nanostructures have been synthesized by a two-step thermal evaporation method. The product was characterized with scanning electron microscopy. X-ray powder diffraction, transmission electron microscopy, and spectrofluorometry. The results of characterization revealed that the urchin-like ZnO nanostructure consists of a spherical metallic Zn core and wurtzite ZnO nanowires growing on the surface of the ZnO buffer which covers the Zn core and the growth directions of wurtzite ZnO nanowires are along < 10-10 >. According to the analysis on these results, a possible two-step growth mechanism was proposed to explain the formation of the urchin-like ZnO nanostructures. The fluorescence-emission mechanisms were also discussed. (C) 2009 Elsevier B.V. All rights reserved.