银纳米粉的比表面积研究

Study on Specific Surface Area of Ag Nanopowders

采用阳极弧放电等离子体方法制备了高纯银纳米粉末。利用X射线衍射(XRD)、透射电子显微镜(TEM)对样品的形貌、晶体结构、粒度进行性能表征。利用静态表面吸附仪依据BET多层吸附原理,在液氮温度下(78K)和气体饱和蒸气压力范围内测试样品对N_2的吸附-脱附等温线,用图解法根据吸附等温线求出单层吸附容量,由BET吸附公式计算出纳米粉末比表面积。结果表明:银纳米粉末的晶体结构为fcc结构,粒径范围在10～50nm,平均粒径为26nm,比表面积为23.81m^2/g。

The pure Ag nanopowders were prepared by anodic arc discharging plasma method. The product was characterized by X-ray diffraction (XRD)and transmission electron microscopy (TEM)to determine the morphology, crystal structure, particle size and size distribution. According to BET multiplayer adsorption theory, N_2 absorption-desorption isotherm of the samples at liquid Nitrogen circumstance (78k), and gas saturation vapor pressure range were measured by using the static volumetric absorption analyzer. Based on absorption isotherm, illustration method was adopted to obtain the single layer adsorption capacity, and BET adsorption equation was utilized to calculate the specific surface area of the nanopowders. The experimental results showed that the crystal structure of the Ag nanopowder was bcc structure, with average size of 26 nm, ranging from 10 to 50nm, and the specific surface area being 23.81m^2/g.