Growth of superhydrophobic Zinc oxide nanowire thin films

Abstract

The growth of ZnO nanowire films by the annealing of Zn films deposited onto borosilicate glass and quartz substrates, at 500 °C, is demonstrated. The as deposited Zn films are polycrystalline with triangular grains aligned along the plane of the substrate. On annealing to 500 °C, the Zn films transform in to polycrystalline ZnO films comprised entirely of nanowires. The ZnO nanowires are 15-100 nm in diameter and about 500 nm long. Wettability studies reveal that the ZnO nanowire films on quartz are superhydrophobic with contact angle as high as 153°. The wettability is reversible under UV irradiation making these films extremely suitable for self-cleaning applications. The growth of nanowires by this technique is attractive since it does not involve very high temperatures and the use of catalysts. © 2012 Elsevier B.V. All rights reserved.