纳米二氧化钛的超声化学法合成

PREPARATION OF NANOCRYSTALLINE TITANIUM DIOXIDE BY SONOCHEMICAL METHOD

在超声波作用下 ,利用不同原料在较低温度下直接合成出二氧化钛纳米晶。实验结果表明 :以钛酸四丁酯作为原料时 ,在液相中可以直接合成锐钛矿相纳米二氧化钛 ,纳米晶粒为短柱状 ,粒径大小约为宽 5nm长 9nm ,粒径分布范围较窄且单分散性好 ;在以TiCl4 为原料时 ,得到金红石型样品 ,粒子为长柱状 ,粒径大小约为宽 3nm长 12nm ,且粒子之间相互取向连生形成羽状的枝蔓晶。利用XRD ,TEM ,TGDTA等测试手段对样品进行表征 ,并且对纳米二氧化钛在超声波作用下的形成机理进行了讨论。

A sonochemical method was used to prepare directly nanocrystalline TiO2 at lower temperature with different raw materials. The experimental results show that taking titanium alkoxide as raw material, nanocrystalline TiO2 of anatase phase is directly synthesized in the presence of water and ethanol under high-intensity ultrasonic irradiation(20 kHz, 100 W/cm2) at 90°C for 3 h. X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetry-differential thermal analysis (TG-DTA), and Fourier transform infrared (FTIR) spectroscopy were used to characterize the TiO2 powder obtained. The TEM images show that the particles of TiO2 are in short-columnar shape with a narrow size distribution and the average size is about 5 nm in width and 9 nm long. When TiCl4 is used as precursor, the products of rutile type are obtained with long-columnar in shape and an average size of 3 nm in width and 12 nm long. This columnar particles are linked together with each other at the certain principle, forming the shape like dendrite crystal. The formation mechanism of nanocrystalline TiO2 under high-intensity ultrasonic irradiation was also discussed.