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以硫酸钛为钛源,浓氨水为沉淀剂,通过水热水解法合成了锐钛矿型纳米TiO2,并利用XRD、SEM、TEM和分光光度计对试样进行了分析。结果表明:未加入浓氨水时,随着水解时间的延长,所得TiO2颗粒的粒径没有明显变化。加入浓氨水后,随着pH值的增加,所得TiO2颗粒的粒径明显变小;但当pH值大于7后,所得TiO2颗粒的粒径则不再随pH值的继续增加而明显变化。UV-VIS分析显示,TiO2颗粒粒径变小有利于TiO2吸收峰的蓝移。在240℃、48h和pH值为9的条件下,合成了呈方形或近椭圆形、粒径约为20nm且分散性较好的TiO2纳米颗粒。
Anatase nano-TiO2 was synthesized by hydrothermal method using titanium sulfate as titanium source and concentrated ammonia as precipitating agent. The samples were analyzed by XRD, SEM, TEM and spectrophotometer. The results showed that when the concentration of ammonia water was not added, the particle size of TiO2 particles did not change significantly with the prolongation of hydrolysis time. With the addition of concentrated aqueous ammonia, the particle size of TiO2 particles decreased obviously with the increase of pH value. However, when pH value was above 7, the particle size of TiO2 particles no longer changed obviously with the increase of pH value. UV-VIS analysis showed that the smaller particle size of TiO2 favored the blue shift of the absorption peak of TiO2. Under the conditions of 240 ℃, 48h and pH value of 9, TiO2 nanoparticles with a square or nearly oval shape, a particle size of about 20nm and good dispersibility were synthesized.