低温水热合成四方相纳米二氧化锆

用硝酸锆作原料，180℃下水热反应18h制得二氧化锆纳米粉体.用XRD、TEM等对所制备粉体作了表征.结果表明硝酸锆直接水热反应，在不同pH条件下，均得到单斜相和四方相混合的ZrO₂粉体.当反应料液中加入一定量的丙三醇时，控制一定pH，硝酸锆180℃水热反应可直接得到单纯四方相ZrO₂粉体，粉体颗粒的粒径在10nm左右.丙三醇的加入还使粉体的粒径更加均匀.对比同样条件下未加入丙三醇的实验表明，丙三醇在实现低温水热合成四方相二氧化锆的过程中起到了重要作用.

Synthesis of ZrO2 nano-powders with pure tetragonal phase by low temperature hydrothermal method

The ZrO₂ nano-powders were prepared from zirconium(Ⅳ) nitrate by the hydrothermal method at 180℃ for 18 h in reaction solution with different pH.The ZrO₂ powders were characterized by XRD and TEM.The ZrO₂ powders of a mixture of m-ZrO₂ and t-ZrO₂ can be directly synthesized from zirconium(Ⅳ) nitrate by the low hydrothermal process in reaction solution with different pH. When the reaction solution was added with glycerin, it was found that ZrO₂ powders with pure tetragonal phase could be directly synthesized at 180℃ with certain pH.The proportion of glycerin and the pH value of reaction solution were interrelated to the crystallographic forms of the zirconia powders.The ZrO₂ powders with pure tetragonal phase are formed at 180℃ for 18 h when glycerin was added to the reaction solution with the ratio ［glycerin］∶［ Zr⁴⁺］ greater than 1∶1 and the pH 9—11, in other experiments mixtures of monoclinic and tetragonal phase ZrO₂ were formed. The ZrO2 powders with pure tetragonal phase were about 10nm and homogenous in size. Compared with the similar experiments without glycerin, addition of glycerin was important in synthesizing the tetragonal phase-ZrO₂ powders by the low temperature hydrothermal method.