一元酸修饰剂对纳米二氧化钛形貌的控制

The control of monacid dressing agent on the topography of nano-sized TiO_2

以偏钛酸为起始反应物,一元酸为修饰剂,采用水热合成法制备纳米金红石型二氧化钛。研究了浓硫酸对偏钛酸的溶解情况,并用X射线衍射仪(XRD)和透射电子显微镜(TEM)对制得的粉体进行表征。结果表明:只有当偏钛酸完全溶解时,才能制得纯相的金红石型二氧化钛。同时一元酸修饰剂的加入对纳米二氧化钛的粒径大小、粒径分布影响很大,并对修饰剂的作用机理进行了讨论。一元酸的加入有助于生成小尺寸的纳米二氧化钛晶体,不同结构的一元酸的抑制作用不同,其中一元酸的酸性促进成核和晶粒长大,空间位阻抑制纳米二氧化钛晶粒的生长。

The hydrothermal synthesis method was adopted to prepare the rutile - type nano - sized TiO2 by using low- cost metatitanic acid as the starting reactant and the monacid as the dressing agent. In this paper, the effects of concentrated H2SO4 on dissolution of metatitanic acid was researched and the prepared powder was characterized by X - ray diffraction （ XRD ） and transmission electron microscopy （ TEM ）. The results showed that the ruffle - type phase - pure TiO2 can only be synthesized when the metatitanic acid was completely dissolved. In the meantime, the presence of dressing agent had big effects on the particle size and size distribution of nano - sized TiO2. The mechanism of action of dressing agent was discussed as well. The monacid favored the formation of small - sized TiO2 crystal and different structures of monacid had different inhibited effects. The acidity of monacid promote nucleation and crystal grain growth and steric effect inhibited the grain growth of nano - sized TiO2.