三维形貌ZnO一维纳米结构的微波水热合成、机理及性能研究

以Zn(NO3)2·6H2O和NaOH为原料,采用微波水热法成功合成了具有三维形貌的单晶ZnO一维纳米结构。采用XRD、SEM及紫外-可见光谱分析等手段对ZnO纳米结构及性能进行了表征;探讨了ZnO复杂纳米结构的形成机理。结果表明:在不同工艺条件下可分别合成ZnO纳米棒、纳米线、纳米推进器、纳米蒲公英及纳米纺锤等结构;微波在合成复杂ZnO纳米结构中起非常重要的作用;纳米ZnO紫外-可见光谱吸收带边出现红移现象。该法没有引入任何金属催化剂、模板或者表面活性剂,从而避免了去除残余添加剂的后续复杂工序。另外,与传统水热法相比,该法可以显著减少反应时间和降低反应温度。

Preparation, Growth Mechanism and Property of Zinc Oxide One-Dimensional Nanostructure with Three-Dimensional Morphology by Microwave Hydrothermal Synthesis

A simple microwave hydrothermal (M-H) solution route employing the reaction of Zn(NO3)2 ·6H2O and NaOH under hydrothermal conditions was demonstrated to successfully synthesize a single-crystal Zinc Oxide (ZnO) one-dimensional nanostructure (ODNS) with a novel three-dimensional (3D) morphology. The microstructures and properties of as-obtained ZnO nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis spectrophotometer. The formation mechanism of the complex nanostructures was proposed. Results show that ZnO nanostructures, such as nanorods, nanowires, nanothruster vanes, nanodandelions and nanospindles can be synthesized under different growth conditions. The microwave plays an important role for the synthesis of ZnO with the complex nanostructures. A red shift of the absorption edge of nano-ZnO was also observed. The absence of metal catalyst, template or surfactant in this method avoids the subsequent complicated workup for the removal of the residual additives. Furthermore, a substantial reduction in the reaction time as well as the reaction temperature is observed compared with the hydrothermal process.