Substrate effect on the growth of well-aligned ZnO nanorod arrays from aqueous solution

A novel method to fabricate the one-dimensional nanostructure of ZnO nanorod arrays onto both Si substrate and zinc foil by a low-temperature aqueous solution method is presented. In the studies reported previously, the use of ZnO nanoparticles on substrates as seed layer helps reduce the diameter of ZnO nanorods. Process parameters such as the pre-deposition of ZnO nanoparticles, aging temperature and time and concentration of reactants are critical for the formation of arrays of nanorods with thin diameter. In this article, we report on an inexpensive and easy process to prepare large-scale, highly oriented arrays on a zinc foil directly without the need of pre-depositing ZnO nanoparticles. A dense and homogeneous ZnO thin film grown on a zinc foil was used as a seed layer; the large-scale ZnO nanorod arrays could be prepared easily by way of varying the pre-treatment conditions of the zinc foil. The use of zinc foil had no influence on the crystal growth and orientation of the ZnO nanorod arrays. The structure of ZnO nanorods on the zinc foil was single crystalline and grown in the [ 0 0 0 1] direction with the zincite structure. We also suggest that the surface condition of the zinc foil strongly influenced the diameter and uniformity of ZnO nanorod arrays. Scanning electron microscopy, glancing X-ray diffraction and transition electron microscopy were employed. (C) 2004 Elsevier B. V. All rights reserved.