Morphology and size controlled synthesis of zinc oxide nanostructures and their optical properties

We report the facile synthesis of zinc oxide (ZnO) nanostructures with different sizes and morphologies by a rapid microwave assisted synthesis using ethylenediaminetetraacetic acid (EDTA) and/or trisodium citrate as chelating agents and their characterization. The obtained ZnO nanostructures having hexagonal Wurtzite structure with different morphologies. With the aid of EDTA and/or trisodium citrate, flowers, flakes, solid spheres and porous spheres were obtained by controlling the crystal growth habit and the concentration of ZnO growth units under microwave irradiation. The optical behaviour was analyzed using UV-Vis spectroscopic technique which indicates that the prepared ZnO nanostructures exhibit band gap between 3.27 and 3.37 eV due to potential fluctuations in electronic band structure of ZnO owing to surface-related defects and/or adsorbed species.