摘要
以硝酸铋和硝酸锆为起始原料,分别采用共沉淀法和聚丙烯酰胺凝胶法制备系列锆掺杂改性Bi2O3的混合氧化物Bi2-xZrxO3+x/2(x=0～1.0)。采用XRD,FTIR和SEM对样品的结构及微观形貌进行分析。研究结果表明:于650℃焙烧处理后,由以上2种方法制备的纯Bi2O3的主晶相均为单斜晶型α-Bi2O3,其中采用聚丙烯酰胺凝胶法及乙二醇和水混合溶剂反序滴定共沉淀法可制备出纯度较高的单斜相α-Bi2O3。锆掺杂改性制备的系列混合氧化物中,当ZrO2掺杂量(摩尔分数)为10%(x=0.2)时,反序滴定共沉淀法能实现均匀共沉淀,形成了组成为Bi1.8Zr0.2O3.1的类似立方相δ-Bi2O3的单一结构固溶体,顺序滴定共沉淀法会产生相分离,导致四方相Bi7.38Zr0.62O12.31固溶体的出现。然而,当采用聚丙烯酰胺凝胶法时,没有得到类似立方相δ-Bi2O3结构的固溶体,主相结构为单斜相α-Bi2O3以及混合部分四方相Bi7.38Zr0.62O12.31和立方相ZrO2。由此可见:采用反序滴定共沉淀法,在650℃低温及合适条件下,掺杂适量的ZrO2能稳定立方相结构的高温离子传导相δ-Bi2O3。
ZrO2-doped Bi2O3 powders Bi2？xZrxO3＋x/2（x=0-1.0） were prepared by coprecipitation and polyacrylamide gel method using Bi（NO3）3？5H2O and Zr（NO3）4？5H2O as materials.The products were characterized using XRD,FTIR and SEM.The results show that after calcined at 650 ？C,for the pure Bi2O3,in the process of coprecipitation with reverse dropping method（adding precipitant to a solution of Bi3＋）,and using ethylene glycol？water system as the dissolvent,pure α-Bi2O3 powder is obtained.But using water as the dissolvent,α-Bi2O3 powder is impurities.And in the process of polyacrylamide gel,pure α-Bi2O3 powder is obtained too.When Bi2O3 is doped with ZrO2 at x=0.2,the process of coprecipitation with reverse dropping method can precipitate Bi and Zr ions simultaneously and form a cubic δ-Bi2O3 phase solid solution with the general formula of Bi1.8Zr0.2O3.1.The process of coprecipitation with natural dropping method results in the phase separation,and the tetragonal Bi7.38Zr0.62O12.31 solid solution is observed.However,the samples prepared by polyacrylamide gel method show no cubic δ-Bi2O3 phase,but only a mixture of α-Bi2O3,the tetragonal Bi7.38Zr0.62O12.31 and the cubic ZrO2.Consequently,the highly conducting phase δ-Bi2O3 can be obtained at 650 ℃ by solid solution formation of Bi2O3 with ZrO2,using reverse dropping coprecipitation method.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2011年第9期2600-2605,共6页
Journal of Central South University:Science and Technology
基金
陕西省科技攻关项目(2008K07-32)
陕西省教育厅专项科研计划项目(08JK228)
