纳米TiO2的溶胶—凝胶法制备及其表征

摘要

以钛酸正丁酯(TNB)-去离子水-盐酸-乙酰丙酮(Acac)的乙醇溶液为反应体系,采用溶胶—凝胶法制备纳米TiO2溶胶颗粒.通过DLS、XRD和HRTEM等表征手段对TiO2颗粒的生成过程、其粒径和晶型的调控等方面进行研究.发现低温环境下TiO2的生成主要经历水解反应形成螯合物、缩合反应生成TiO2溶胶、TiO2溶胶颗粒融合这三个阶段.并且通过调节反应温度和催化剂浓度,可在无需高温锻烧的情况下,制得具有典型锐钛矿晶型的高分散性TiO2溶胶颗粒.%Nano-TiO2 sol particle is prepared by sol-gel method using the designed ethanol solution of butyl titanate (TNB), deionized water, hydrochloric acid and acetylacetone (Acac). The generation process of TiC>2 and its particle size and crystal are characterized by dynamic light scattering (DLS), X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM). It is found that TiO2 generation process consists of three stages; hydrolysis reaction, condensation reaction, and sol-particle combination. The particle size and crystal can be controlled by reaction temperature and catalyst concentration. Especially when the reaction temperature is 70°C, the amount of hydrochloric acid catalyst 0. 5 mol/ L, the molar ratio of deionized water to TNB 4, a kind of nano-Ti02 sol particle with high dispersion and typical anatase crystal can be obtained just via a low-temperature sol-gel process.