水热法合成Bi_(1.5)ZnNb_(1.5)O_7纳米粉体

SYNTHESIS OF Bi_(1.5)ZnNb_(1.5)O_7 NANOPOWDER BY THE HYDROTHERMAL METHOD

以Bi(NO3)3·5H2O,ZnO和Nb2O5为原料,KOH作为矿化剂,用水热法合成了单相Bi1.5ZnNb1.5O7粉体。用N2吸附法测定单相Bi1.5ZnNb1.5O7粉体的比表面积并计算相应的粒径。研究了KOH浓度、合成温度和反应时间对粒径的影响。用X射线衍射分析合成粉体的物相组成,并通过Scherrer公式计算粉体晶粒的尺寸。用透射电子显微镜分析合成粉体的形貌。结果表明:采用水热法可以合成单相立方焦绿石结构的Bi1.5ZnNb1.5O7纳米粉体。改变水热反应条件,可以控制合成粉体的粒径和比表面积大小。当KOH浓度为1.8mol/L,温度为180～220℃,反应时间为24h时,合成的Bi1.5ZnNb1.5O7纳米粉体的最小粒径为51nm,最大比表面积为28.8m2/g。

Cubic pyrochlore phase Bi1.5ZnNb1.5O7 powder was successfully synthesized by the hydrothermal method （HTM） with Bi（NO3）3·SH2O, ZnO and Nb2O5 as starting materials and KOH as mineralizer. The specific surface area of the powders was detected by the N2 adsorption method, and the sizes of synthesized powder were calculated. The effects of KOH concentrations, synthesis temperature and reaction time on particle size were investigated. The phase and microstructure of the powder were analyzed using X-ray diffraction and transmission electron microscope. The crystalline sizes were determined by the Scherrer equation. The results show that the cubic pyrochlore phase Bi1.5ZnNb1.5O7 powder can be obtained by HTM. The minimal powders＇ size is 51 nm and the maximal specific surface area is 28.8 m^2/g when the Bi1.5ZnNb1.5O7 powder is synthesized under hydrothermal conditions with a synthesis temperature of 180-220 ℃, a reaction time of 24h and a KOH concentration of 1.8 mol/L.