ZnO nanorods (NRs) were hydrothermally synthesized by using equimolar zinc nitrate hydrate (Zn(NO3)2 · 6H2O) and hexamethylenetetramine (C6H12N4) solutions. The shape of the nanostructures, obtained by aqueous method, was greatly influenced by the growth temperature and the molar concentrations. NRs grown at higher temperature (90°C) have rounded tips, whereas nanostructures of hexagonal flat-end shape were obtained at 75°C. Hardly any nanostructures were observed by further reducing the temperature to 60°C. In addition, solutions with higher molarity favored the appearance of nanoflowers. Scattered ZnO NRs were observed on silicon substrate, whereas aligned ZnO nanowires (NWs) 50-70nm in diameter were obtained at 75°C by introducing sputtered ZnO film as a seed layer. Highresolution transmission electron microscopy (HRTEM) confirmed the growth of ZnO nanowires along  direction. A band-edge luminescence along with a broad visible spectrum was observed for the ZnO nanowires.
Bibliographical noteFunding Information:
This work was supported by the ‘‘System IC 2010’’ Project of Korea Ministry of Commerce, Industry and Energy, and the Second Stage of Brain Korea 21 Project in 2007.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)