水热法制备大比表面积二氧化钛纳米片空心微球

Preparation of Hollow Microspheres of Titania with Nanosheets by Alkaline Hydrothermal Method

常温下在SiO2纳米球表面包覆一层TiO2,通过碱性水热法移除SiO2纳米球后,被包覆的微球转变成由纳米片组成的TiO2空心微球。采用X射线衍射,扫描电子显微镜,透射电子显微镜和氮气吸附--脱附分析对包覆微球和TiO2空心微球进行表征。结果表明,氨水和钛酸四丁酯的含量对包覆微球的形貌有重要影响,NaOH浓度也直接影响空心微球的形貌和比表面积。TiO2空心微球表面是由厚度仅为几个nm,长度为100nm以上的纳米片组成,其晶体结构为锐钛矿相。TiO2空心微球的比表面积高达185.7m2/g。

The hollow microspheres of TiO2 with the nanosheets were obtained after the SiO2 nanospheres coated with the monolayer TiO2 were removed by an alkaline hydrothermal method.The coated microspheres and TiO2 hollow microspheres were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy and nitrogen adsorption-desorption analysis,respectively.The results indicate that the amount of ammonia and tetrabutyl titanate has an important influence on the morphology of the coated microspheres,and the concentration of NaOH affects the morphology and the surface area of the TiO2 hollow microspheres.The surface of TiO2 hollow microspheres is composed of TiO2 nanosheets with the thickness of several nanometers and the length of more than 100 nm,and the crystal phase of TiO2 hollow microspheres is pure anatase.The specific surface area of the TiO2 hollow microspheres is up to 185.7m2/g.