SiO_2:nm-Ag的制备及其结构特性

Preparation and Structural Properties of SiO_2 :nm-Ag Fine Powders

采用溶胶–凝胶法制备了掺纳米银的二氧化硅(SiO2:nm-Ag)微粉,并探讨其形成机理。用TG-DTA、XRD和TEM研究了微粉的结构特性及其影响因素。结果表明,通过控制制备条件和退火温度可以得到不同结构的SiO2:nm-Ag微粉。干凝胶研磨后在500℃退火,得到的微粉中SiO2主要以非晶硅藻土形式出现,银簇细小而均匀;在900℃退火时得到的微粉中,SiO2主要以低温方石英形式出现,银簇较大且分散。

Fine powders formed by nanometer Ag clusters embedded in SiO2 (SiO2:nm-Ag) were prepared by sol-gel method. The mechanism of the forming process was also explored. By using TG-DTA, XRD and TEM, the samples structural properties and their dependence on the fabrication parameters were studied. The result shows that SiO2:nm-Ag fine powders with different structures can be prepared by controlling preparation conditions. In the SiO2:nm-Ag fine powders prepared by annealing the grinded gel at 500℃, SiO2 mostly appeared with amorphous diatomite, Ag clusters are fine and well-distributed; and if changing the annealing temperature to 900℃, SiO2 mostly appeared with cristobalite low, and the Ag are aggregated into big clusters.