Abstract: The ultrafine ZrO₂ nanocrystals with high surface area have been synthesized by the solvent-assisted vapor hydrolysis method. The effects of solvent and precursor concentration on the crystal structure of the ZrO₂ nanocrystals were investigated. The structural properties of the samples were characterized by X-ray diffraction(XRD),N₂ adsorption-desorption,scanning electron microscope(SEM),transmission electron microscope(TEM) and corresponding selected area electron diffraction(SAED). The experimental results demonstrated that the synthesized ZrO₂ nanocrystals had an average crystal size below 5nm and specific surface areas in the range of 237—450m²/g. Moreover,the synthesized samples possessed tetragonal phase and even higher specific surface areas using precursor of low concentration and in the presence of solvent,while,the samples with the monoclinic and tetragonal phase coexisted and lower specific surface areas were also obtained when we increased the precursor concentration or did not use solvent. These findings indicated that the precursor concentration and the solvent both exhibited excellent controllability over the properties of ZrO₂ nanocrystals such as crystal structure,specific surface area and crystal size.

Key words: zirconia, solvents, synthesis

摘要： 在溶剂辅助作用下，通过蒸汽相水解一步合成了具有高比表面积的超细二氧化锆纳米晶体， 着重研究了前体浓度与溶剂种类等合成因素对二氧化锆纳米晶体结构的可控性。采用X射线衍射（XRD）、N₂吸附-脱附、扫描电镜（SEM）、透射电镜（TEM）、选区衍射（SAED）等手段对纳米晶体的结构进行了表征。结果表明，合成的样品具有高达237~450m²/g的比表面积和平均粒径小于5nm的超细纳米晶体颗粒。研究还发现，在较低的前体浓度和溶剂存在的条件下合成的样品显示了纯四方相结构和更高的比表面积，增加前体浓度或无溶剂条件下合成的样品则具有四方相和单斜相的混合相结构和更低的比表面积，表明通过调变前体浓度和溶剂可以实现对二氧化锆纳米晶体的晶相、比表面积和颗粒尺寸的有效调控。

关键词: 氧化锆, 溶剂, 合成