开口型SnO_2空心球表面载银制备及其表征

Preparation and Characterization of Silver Coated Hollow SnO_2 Sphere with Open Structure

以锡酸钠和尿素为原料,采用一步水热法和两步原位化学还原法分别制备出SnO2空心球表面载有银亚纳米颗粒的复合粉体,通过X射线衍射（XRD）、扫描电子显微镜（SEM）、能谱仪（EDS）、透射电子显微镜（TEM）等研究了表面银颗粒的厚度及分布均匀性。结果表明,2种方法均能制备出平均粒径为14μm、分散性良好的空心微球;一步水热法制备的SnO2空心球表面银颗粒细小且有团聚现象,而采用两步原位化学还原法在SnO2空心球表面获得了一层由亚纳米银颗粒组成的厚度均匀的银壳,银颗粒的粒径为100300nm;还原剂葡萄糖的浓度对银颗粒粒径及分布影响明显。

Silver coated hollow SnO_2 microspheres were prepared by a one-step hydrothermal method and a two-step in situ chemical reduction method using sodium stannate and urea as the main raw materials. The thickness and uniformity of the surface of Ag nanoparticles were characterized by X-ray Diffraction(XRD), Scanning Electron Microscopy with Energy-dispersive(SEM/EDS) and Transmission Electron Microscopy(TEM). The results show that well dispersed hollow microspheres with diameter of 1~4 μm are prepared by both methods. The morphology of Ag nanoparticles on the surface of hollow Sn O_2 sphere prepared by the one-step hydrothermal method is fine with agglomeration, while an uniform thickness silver shell with a diameter of 100~300 nm is obtained by two-step in situ chemical reduction method. The concentration of reducing agent glucose influences the size of silver nanoparticles and silver layer thickness obviously.