熔盐法二氧化钛针状晶的制备及表征

Characterization of Salt Flux Method Prepared Titania Needle-Like Crystals

以纳米TiO2和AlCl3·6H2O为原料，利用NaCl和KCl复合熔盐体系在1200℃下制备出了直径为2～5μm，长度为30～80μm的金红石型TiO2针状晶。采用电子衍射、XRD、SEM和EDS方法对其形貌，组成及晶型进行了初步分析。结果表明，合成出的针状晶可分为实心针状晶和空心管状晶两种。在熔盐的液相环境中，TiO2晶粒沿着Z轴方向优先生长，最终生成实心针状晶，而管状晶认为是由长板状晶达到一定尺寸时通过卷曲成管形成。

By using nano-titania and A1Cl3· 6H2O as raw materials, rutile TiO2 needle-like crystals which are 2 - 5 μm in diameter and 30 - 80 μm in length were prepared at 1 200℃ in NaCl and KCl fluxs. The crystalline morphology and the compositions of the needle-like crystals were investigated by means of XRD,SEM,EDS and TEM. The results indicate that there are two kinds of forms for synthesized needlelike crystals; one is solid needle-like, and the other tube-like. In the presence of liquid phase of molten salt, TiO2 grains grow preferably along z-axis direction and form solid needle-like TiO2 single crystals finally. Tube-like crystals are formed by the crimp mechanism of board-like grains with proper size.