Low temperature synthesis of spindle-like ZnO nanostructures under microwave irradiation

A simple and general microwave route is developed to synthesize nanostructured ZnO using Zn(acac)(2)center dot H2O (acac = acetylacetonate) as a single source precursor. The reaction time has a great influence on the morphology of the ZnO nanostructures and an interesting spindle-like nanostructure is obtained. The microstructure and morphology of the synthesized materials are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). It is found that all of them with hexagonal wurtzite phase are of single crystalline structure in nature. Ultraviolet-visible (UV-vis) absorption spectra of these ZnO nanostructures are investigated and a possible formation mechanism for the spindle-like ZnO nanostructures is also proposed.