二氧化钛水热合成单分散立方形貌PZT粉体

本文以TiO2、ZrOCl2·8H2O和Pb（NO3）2为反应物、KOH为矿化剂水热合成得到组成均一且外观具有规则立方形貌的单分散PZT粉体．研究了矿化剂浓度、水热反应温度和反应时间对产物相组成和外观形貌的影响。结果表明：在KOH浓度为2．0mol／L、水热合成温度为160℃、反应时间为18h时可得到最佳形貌和颗粒尺寸（1．5～2μm）的PZT。进一步的研究表明，水热温度的增加有利于得到大尺寸立方形貌的PZT粉体，这一现象与以钛的醇盐为原料时所得的结果正好相反。反应机制的分析表明：在本合成体系中，PZT的形成过程主要是TiO2的溶解、Pb^2＋和ZrOCl2的水解以及PZT晶核的形成和生长过程。其中矿化剂对TiO2的溶解是整个水热过程的控制步骤。

Hydrothermal Synthesis of Monodisperse Cubic Morphology PZT Powders from TiO2 Precursor

The homogeneous and regular cubic morphology lead zironate titanate （PZT） particles had been synthesized by hydrothermal method using TiO2, Pb （NO3）2, ZrOCl2·8H2O as starting materials and mineralizer concentration, hydrothermal temperature and hydrothermal time on KOH as mineralizer. The effects of product phase composition and morphology had been investigated. The results showed that PZT with the best morphology and particles size （1.5- 2μm） was obtained with KOH concentration of 2. 0mol/L, the hydrothermal temperature of 160℃ and the hydrothermal time of 18h. The increasing of mineralizer concentration and hydrothermal temperature would yield the bigger cubic morphology PZT, which is opposite to the hydrothermal method with titanium alkoxide as starting material. A possible formation mechanism is proposed. The formation process of PZT consists of the dissolution of TiO2, the hydrolyzation of Pb^2＋ and ZrOCl2, the nucleation and growth of PZT. In which, the dissolution of TiO2 is rate-controlling step of the whole hydrothermal process.