Synthesis and Optical Absorpition Properies of Anatase TiO2 Nanoparticles via a Hydrothermal Hydrolysis Method

摘要:

以硫酸钛为钛源，浓氨水为沉淀剂，通过水热水解法在240 ℃，48 h，pH=9时合成了粒径约为20 nm的锐钛矿TiO2纳米颗粒。利用X射线衍射仪（XRD）、热场发射扫描电子显微镜（SEM）、热场发射透射电子显微镜（TEM）和紫外可见分光光度计（UV-VIS）对试样进行分析。结果表明：硫酸钛溶液水热水解法不加入浓氨水时，随着水解时间的延长，虽然获得的锐钛矿型TiO2颗粒的粒径已达到了纳米级，但是其粒径的变化不明显；硫酸钛溶液水热水解法时加入浓氨水，合成锐钛矿型TiO2颗粒的粒径明显变小，但是，随着pH值的增加，合成锐钛矿型TiO2颗粒的粒径变化不明显。对不同条件下水热水解法合成的TiO2进行UV-VIS分析可得，TiO2颗粒粒径的变小有利于TiO2吸收峰的蓝移。

Abstract:

Anatase TiO2 nanoparticles with the size of about 20 nm were synthesized using Ti(SO4)2 as titanium source and stronger ammonia water as precipitant at 240 °C for 48 h with pH=9 by a hydrothermal hydrolysis method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and ultraviolet-visible absorption spectroscopy (UV-VIS). XRD analysis shows that the phase of the sample is anatase TiO2. SEM and TEM analysis confirms that with the increase of the reaction time, the size of TiO2 nanoparticles prepared without stronger ammonia water can reach nanometer grade, but its change is not obvious. With the addition of stronger ammonia water, the size of TiO2 nanoparticles becomes small noticeabley. With the further increase of pH value, its influence on the TiO2 nanoparticles size is not obvious. And UV-VIS analysis shows that the reduction in the size of anatase TiO2 nanoparticles is beneficial to the blue shift of their absorption peak.