常压水解法制备纳米二氧化钛及表征

Preparation and characterization of nano-sized TiO_2 by atmospheric hydrolysis method

以硫酸法工业生产钛白粉的中间产物硫酸氧钛及工业尿素为原料,采用常压水解法,研究了制备纳米二氧化钛粉体的最佳工艺条件。详细考察了纳米二氧化钛制备工艺过程中的主要影响因素,即硫酸氧钛质量浓度、尿素质量浓度、硫酸氧钛与尿素物质的量比等。根据实验工艺参数,得出纳米二氧化钛的最佳制备方案：硫酸氧钛与尿素物质的量比为1∶2,硫酸氧钛质量浓度为40 g/L,尿素质量浓度为50 g/L;在反应体系中添加适量表面活性剂,反应温度为85℃±5℃,在高速搅拌下反应2 h,始终保持pH为2;反应完成后,产物用去离子水洗涤,再用无水乙醇洗涤1次;滤饼在85℃干燥2~3 h,最后在700℃焙烧2 h,即得到纳米二氧化钛产品。制备的纳米二氧化钛超细粉晶相为锐钛型,粒径为7~13 nm。

Optimum conditions of preparing nano-sized titanium dioxide （ TiO2 ） powder by atmospheric hydrolysis method were studied,in which the intermediate product titanyl sulfate （ TiOSO4 ） from industrial titanium dioxide production with sulfuric acid process and industrial urea were used as raw materials. Major influencing factors, such as mass concentrations of titanyl sulfate and urea,as well as amount-of-substance ratio of titanyl sulfate to urea in production process of nanosized TiO2 were investigated. According to experimental parameters, optimum program for preparation of nano-sized TiO2 was obtained. Namely, amount-of-substance ratio of TiOSO4 to CO（NH2 ）2 was 1：2, mass concentrations of TiOSO4 and CO （ NH2 ）2 were 40 g/L and 50 g/L, respectively;adding a certain amount of surfactant into the reaction system;reaction temperature was 85℃ ± 5 ℃, reaction time was 2 h under high - speed stirring, and maintaining pH at 2. After reaction, the product was washed with deionized water, and then washed again with ethanol. Finally, nano-sized TiO2 was obtained after the product was dried at 85 ℃ for 2 - 3 h and calcined at 700 ℃ for 2 h. Prepared TiO2 was anatase with particle size of 7 - 13 nm.