Authors: J.-Y. Yang, H.-W. Cheng, T.-C. Cheng, Y. Li
Affilation: National Chiao Tung University, Taiwan
Pages: 460 - 463
Keywords: hydrothermal growth, ZnO, nanostructures, zinc thin films, seed layer
Different zinc oxide nanostructures are selectively synthesized by a simple reaction of zinc acetate dihydrate with hexamethyltetramine (HMT) under mild hydrothermal conditions using zinc thin films as seed layer. Scanning electron microscopy (SEM) result of Fig. 1 shows that zinc thin films were oxidized to hexagonal ZnO seeds in the absence of zinc salt and base under hydrothermal conditions. The effect of a mixed water/ethanol solvent with various ethanol contents on the morphology, nanostructure, and compositional properties of the synthesized zinc oxide is firstly investigated. SEM studies, as shown in Fig. 2, show that the ZnO pillar and wire structures could be obtained at low ethanol contents, while high ethanol contents are favorable for the formations of ZnO thin film structures through coalescence of adjacent rods. As shown in Fig. 3, X-ray diffraction (XRD) studies show that the phenomenon of crystal tilt appeared as the ethanol content increases. Results indicate that the ethanol could acts as a shape inducing molecule. The possible growth mechanism for the growth of different ZnO nanostructures using zinc thin films as seed layer and various ethanol contents in a mixed water/ethanol solvent will also be discussed.