Controllable Synthesis of Highly Dispersed ZnO Nanoparticles and Nanorods

Highly dispersed ZnO nanoparticles have been successfully prepared after calcinations of the precursors obtained at room temperature via the chemical reaction of zinc sulfate and sodium carbonate in the presence of cetyltrimethylammonium bromide. The particle size distribution of ZnO nanoparticles varies from 61.5 to 79 nm, exhibiting a highly dispersive and narrow size distribution. The average diameter size is 69.8 nm. The transmission electron microscopy shows that ZnO nanoparticles have a hexangular structure, exhibiting a polycrystalline feature. After a hydrothermal process (120-200 degrees C) for the precursors, hexahedral prismlike nanorods (lengths ranging from 3 to 5 mu m and diameters of 80-300 nm) and hexahedral prismlike nanorods with two sharp tips (lengths of 30-70 mu m and central diameters of 1.5-2.0 mu m) can be synthesized. The photoluminescent spectra reveal that the synthesized ZnO nanoparticles present a weak and broad emission band around 400 nm, whereas hexahedral prismlike nanorods and hexahedral prismlike nanorods with two sharp tips exhibit a strong and narrow emission band at 386 and 384 nm, respectively. All of the synthesized ZnO samples show good photocatalytic reactivity on the decomposition of organic dyes.