Ag@SiO_2核壳结构颗粒的可控合成与性能研究

Controlled synthesis and properties research of Ag@SiO_2 core shell particles

首先通过柠檬酸钠还原法制备了粒径分别约为20nm和50nm的银纳米颗粒。采用改进的Stber法在银颗粒外面包裹二氧化硅,通过控制正硅酸四乙酯(TEOS)的滴加时间和滴加量控制壳层生长来制备Ag@SiO_2核壳结构颗粒,采用TEM,红外、紫外–可见光光谱分析等方法系统表征了样品形貌、结构及光学性能。结果表明,采用上述方法成功制备了壳层厚度分别为16,22,60,69,79nm的核壳结构颗粒。光谱分析结果指出,该类核壳结构颗粒表面等离子共振吸收峰位对于分散介质相当敏感。

Silver nanoparticles with particle sizes of about 20 and 50 nm were firstly synthesized by reducing agent of sodium citrate, and then silver nanoparticles coated with amorphous silica were prepared using improved Stber method. Thickness of silica shell was altered by varying the droping volume and time of tetraethyl orthosilicate (TEOS), the morphology, structure and photographic properties of the samples were investigated by TEM, FT-IR and UV-VIS absorption spectrometer. Results show that Ag@SiO_2 core sh...