摘要：通过单流匀速滴定法在二氧化钛颗粒表面均匀包覆一层二氧化硅,系统地研究热处理温度对这层硅包覆层的形貌和相组成的影响;采用X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)、透射电子显微镜(TEM)和傅立叶红外光谱仪(FTIR)等手段对包硅二氧化钛颗粒进行表征。结果表明:150℃热处理形成连续致密的硅二氧化硅覆层;500℃热处理3 h后形成岛状二氧化硅膜;700℃热处理后形成不连续的硅二氧化硅覆层,并有脱落的倾向;当温度升到1 000℃时,硅二氧化硅覆层会脱落,二氧化钛的粒径增大,大约在1 000℃,二氧化硅包覆层结晶化。

关键词： 二氧化钛;二氧化硅;包覆层;热处理

Abstract：The silica-coated titania particles were prepared by the cocurrent titration method under mild conditions. The influences of thermal treatment on the microstructure and phase composition of the silica coating were systematically investigated. The titania particles were characterized by X-ray diffraction（XRD），X-ray photoelectron spectroscopy（XPS）， transmission el ectron microscopy （TEM） and Fourier transform infrared spectroscopy （FTIR）. The experimental results showed that the continuous and dense silica coating were obtained under low temperature（150 ℃）， the island-like coating layer was observed on the surface of titania particles at 500 ℃ for 3 h. At 700 ℃， the discontiguous silica coating was found on the surface of titania particles. With further increasing calcining temperature， the silica coating came away from the surface of titania particlesat 1 000 ℃ and the particle size of the titania particles increased. The silica layer was crystallized at about 1 000 ℃. 

Keywords： titania； silica； coating layer； thermal treatment