Facile hydrothermal synthesis of large scale ZnO nanorod arrays and their growth mechanism

Large scale ZnO nanorod arrays (ZNAs) were grown on the indium-doped tin oxide (ITO) glass substrate by a novel and facile hydrothermal method at low temperature. The obtained nanorods were characterized by SEM, XRD, TEM and PL. It is shown that the average diameter of ZnO nanorods (similar to 500 nm) grown on the bare substrate is much bigger than that of nanorods grown on the ZnO-seed-coated substrate (similar to 100 nm). ZNAs grown on ZnO-seed-coated substrate are highly aligned. All the as-grown ZnO nanorods have a very good crystallinity with hexagonal wurtzite structure and grow along the c-axis. Zinc metal spiral plays important roles for the growth of ZnO nanorods, which conduces to generate the additional growth unit of [Zn(OH)(4)](2-). (C) 2013 Elsevier B.V. All rights reserved.