Orientation and actual growth mechanism of ZnO nanorods through hydrothermal method on gold seed layer

In this study, the hydrothermal method was employed to synthesize an oriented ZnO nanorod array on an annealed gold seed layer coated on a glass substrate from different precursor concentrations. Zinc nitrate hexahydrate and hexamethylenetetramine were used as starting materials for ZnO nanorod growth. The effect of gold seed layer roughness on the orientation of ZnO nanorods is presented. The morphology of the nanorods shows that oriented ZnO nanorods were obtained after deposition on the annealed gold seed layer. Energy dispersive x-ray spectroscopy was used to identify the elemental composition and identify the elements present in the samples. The XRD pattern shows that the nanorods have a good crystalline structure, with dominant (002) peaks for all concentrations, which reflects that the c-axis of the elongated nanorods is oriented normal to the substrate. The proposed growth mechanism for the growth of ZnO nanorods is presented.