Fabrication of ZnO nanowires through thermal heating of metallic Zn by solar energy

ZnO nanowires were synthesized in a short time of a few seconds through a simple thermal evaporation of Zn powder using solar energy under air atmosphere. The Zn powder was heated by focusing sunlight on the Zn powder employing a magnifying lens. This strategy heated Zn to its evaporation temperature resulting in its oxidation in air. This procedure formed ZnO nanowires of ∼10 nm diameter and ∼2 μm length. As only Zn powder without any catalysts was used as the source material, it is suggested that the growth of the nanowires occurs through a vapor-solid mechanism. The cathodoluminescence (CL) spectrum from such ZnO nanowires showed strong ultraviolet emission indicating their highly crystalline quality besides good optical properties.