We report a comparative study of metal-surface-catalyzed ZnO nanowire growth. The growth is initiated on Si and sapphire substrates, which were prepared with thermal vapor deposited thin metallic films. As described earlier for Au films, these films may change morphology at growth temperatures and catalyze ZnO nanowire growth. Here we use materials diagnostics based on synchrotron X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, photoluminescence, and energy-dispersive X-ray spectroscopy to compare the growth from Au, Ag, Fe, and Ni catalysts. We relate the materials properties of the ZnO nanowires to the substrate and catalyst surface structure and comment on the possible growth modes using each of these metal catalysts.

We demonstrate that synchrotron x-ray powder diffraction (XRD) is a powerful technique for studying the structure and self-organization of zinc-oxide nanostructures. Zinc-oxide nanorods were prepared by a solution-growth method that resulted in uniform nanorods with 2-nm diameter and lengths in the range 10–50 nm. These nanorods were structurally characterized by a combination of small-angle and wide-angle synchrotron XRD and transmission electron microscopy (TEM). Small-angle XRD and TEM were used to investigate nanorod self-assembly and the influence of surfactant/precursor ratio on self-assembly. Wide-angle XRD was used to study the evolution of nanorod growth as a function of synthesis time and surfactant/precursor ratio.