Growth of zinc oxide nanowires by a hot water deposition method

Recently, various methods have been developed for synthesizing zinc oxide (ZnO)nanostructures, including physical and chemical vapor deposition, as well as wet chemistry.These common methods require either high temperature, high vacuum, or toxic chemicals. Inthis study, we report the growth of zinc oxide ZnO nanowires by a new hot water deposition(HWD) method on various types of substrates, including copper plates, foams, and meshes, aswell as on indium tin oxide (ITO)-coated glasses (ITO/glass). HWD is derived from the hotwater treatment (HWT) method, which involves immersing piece(s) of metal and substrate(s) inhot deionized water and does not require any additives or catalysts. Metal acts as the source ofmetal oxide molecules that migrate in water and deposit on the substrate surface to form metaloxide nanostructures (MONSTRs). The morphological and crystallographic analyses of thesource-metals and substrates revealed the presence of uniformly crystalline ZnO nanorods afterthe HWD. In addition, the growth mechanism of ZnO nanowires using HWD is discussed. Thisprocess is simple, inexpensive, low temperature, scalable, and eco-friendly. Moreover, HWDcan be used to deposit a large variety of MONSTRs on almost any type of substrate material orgeometry.