反相微乳液合成单分散的四方形SnO_2纳米晶(英文)

Reverse Microemulsion Synthesis of Monodispersed Square-shaped SnO_2 Nanocrystals

通过设计反相微乳液反应体系,在水热条件下缓慢氧化SnF_2,合成了单分散的四方形SnO_2纳米晶,利用X射线多晶粉末衍射、扫描电镜、高分辩透射电镜对合成样品的形貌和结构进行了表征.实验结果表明,通过控制油胺的添加量调控微乳液水相的pH值,可以对SnO_2的形貌进行调控.使用适当量的油胺,可以获得分散性极好、大小为10 nm左右的规则四方SnO_2纳米晶.合适的pH值有利于晶核的定向生长,从而在微乳液反应器中形成了规则的SnO_2四方纳米晶。

A nanosized reverse microemulsion reactor was designed for the fabrication of monodispersed SnO2 nanosquares by oxidation of SnF2 under hydrothermal conditions. As-prepared samples were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope and high resolution transmission elec- tron microscope. The results show that the morphology of the SnO2 nanocrystals can be controlled by regulating the amount of the used oleylamine which direct influenced the pH values of the aqueous phase. Well monodispersed SnO2 nanosquares with the size around 10 nm can be obtained. A proper pH value could benefit the oriented attachments of the crystalline seeds which gradually grew into a square-plate NCs shape in the microemulsion reactor.