An alternative approach to in situ synthesize single crystalline ZnO nanowires by oxidizing granular zinc film

ZnO nanowires were synthesized by a relatively simple process—oxidizing granular Zn films at a relatively low temperature (450–600 °C) without catalyst. The zinc film was initially fabricated by sputter deposition in an argon atmosphere at ambient temperature using Zn metal as the sputter target. After subsequent annealing in an air or oxygen atmosphere, ZnO nanowires were found to grow from individual Zn nanograins. The investigation has also showed that the nanowires preferably grow from relatively porous Zn film and a small amount of oxygen flow is beneficial to the growth of nanowires. The resultant single crystal ZnO nanowires obtained from annealing at 600 °C in an oxygen atmosphere had a mean diameter less than 50 nm and had a very good structural quality. This process provides an alternative method to produce ultra-fine ZnO nanowires standing on the substrate.