Synthesis of crystalline ZnO nanostructures on arbitrary substrates at ambient conditions

Abstract

In this paper, we report on a new method of synthesis for ZnO nanowires on arbitrary substrates and nanowalls on aluminum coated substrates at ambient conditions. Our method is based on sonochemical reaction of Zinc acetate dihydrate (Zn(O2CCH3)2-2H2O) Zinc nitrate hexahydrate (Zn(NO3)2-6H2O) and hexamethylenetetramine (HMT, (CH2).6N4) in aqueous solutions. Repetitive growth cycles resulted in synthesis of ZnO nanowires and nanowalls with controlled dimensions and large aspect ratios. Extensive analysis by transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS) and UV-Visible spectroscopy revealed the crystalline ZnO composition of the synthesized nanostructures. The proposed method is a rapid, inexpensive, low-temperature, catalyst-free, CMOS compatible and environmentally benign alternative to existing growth techniques.