SiO_2/TiO_2核壳纳米复合粒子的制备与表征

Preparation and characterization of SiO_2/TiO_2 core-shell nanocomposites

利用钛酸丁酯的水解缩合在Si O2微球表面沉积Ti O2层,制得二氧化硅/二氧化钛(Si O2/Ti O2)核壳纳米复合材料。采用TEM、EDS、FT-IR和XRD等对所得的复合材料的形貌及结构进行表征。结果表明,该复合物具有明显的核壳结构。内核Si O2粒子粒径约220 nm,表面Ti O2包覆层厚度约20nm,两者之间形成了Ti-O-Si键。Ti O2层的厚度随着钛源的量增加而增大。该Si O2/Ti O2核壳结构复合物经高温处理后,壳层Ti O2由无定型转化为锐钛矿型。

Si O2/ Ti O2core-shell nanocomposites were prepared by the modification of titania on silica microspheres through the hydrolysis of tetra-butyl ortho-titanate（ TBOT） precursor. The morphology and structrue of the core-shell nanocomposites were characterized by transmission electron microscopy（ TEM）,energy dispersive spectroscope（ EDS）,Fourier transform infrared spectroscopy（ FT-IR） and X-ray diffraction（ XRD）. The results show that the composites comprise obvious coreshell structure composed of Si O2 core with an average diameter of about 220 nm and an outer Ti O2 layer with a thickness of about 20 nm. In addition,Ti-O-Si chemical bonds are formed between the Si O2-shell and the outer Ti O2layer（ during the formation of the core-shell composite particles）. The thickness of the Ti O2 layer is increased with the increase of TBOT precusor,whereas the amorphous crystalline Ti O2 layer is transferred into anatase after the heat treatment.