Zinc Oxide Nanostructures Formed by Wet Oxidation of Zn Foil

Zinc oxide (ZnO) nanostructures were successfully grown by wet oxidation of zinc (Zn) foil in water at 90 °C for 2 to 8 h. The effect of etching the Zn foil before oxidation treatment on the morphology of ZnO nanostructures was investigated. Hemispherical structures of ZnO nanowires, nanorods and nanotubes were produced on etched Zn foil at different oxidation times. The growth of hemispherical structures was possibly due to the formation of pits along the grains after etching. Without etching, relatively aligned nanorods were formed after wet oxidation with the structure becoming coarser after longer oxidation time. The anisotropic growth ZnO nanostructures on the surface of Zn foil by wet oxidation could be due to the inherent growth habit of ZnO crystal.