Microwave-Assisted Synthesis of Various ZnO Hierarchical Nanostructures: Effects of Heating Parameters of Microwave Oven

Several novel hierarchical ZnO nanostructures have been successfully prepared in mixed solvents of ethylene glycol (EG)−water via a facile microwave-assisted method. By only change of the heating parameters of the microwave oven, ZnO nanostructures with straw-bundle-like, wide chrysanthemum-like, and oat-arista-like morphologies and microspheres were obtained. The products were characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and room-temperature photoluminescence spectrometry (PLS). The possible mechanisms for the growth of these hierarchical ZnO nanostructures were tentatively proposed.