Room-temperature fabrication of highly oriented ZnO nanoneedle arrays by anodization of zinc foil

Highly oriented ZnO nanoneedle arrays were electrochemically prepared by anodization of zinc foil in a freshly prepared zincate saturated aqueous solution at room temperature. Typically, the needles have a length of 550–650 nm with a tip diameter of 10–15 nm and a root diameter of 50–60 nm, and grow along their [001] direction. The crystal structure of the ZnO nanoneedles was confirmed by scanning and transmission electron micrographs, x-ray diffraction patterns and photoluminescence spectra.