微晶纤维素模板法制备纳米二氧化钛及表征

Preparation and characterization of nano-TiO_2 with template method of microcrystalline cellulose

以TiCl4为原料,微晶纤维素为模板,制备了具有微晶纤维素特征形貌的纳米二氧化钛。借助透射电子显微镜、环境扫描电子显微镜、傅里叶变换红外光谱、X射线衍射、热重分析等分析方法对样品进行表征,探讨纳米二氧化钛的形成机理。结果表明:在500℃焙烧得到准球形锐钛矿纳米二氧化钛,粒径为15 nm;在700℃和900℃焙烧分别得到夹有金红石型的锐钛矿和红晶石型纳米二氧化钛,并且随着焙烧温度的升高,纳米二氧化钛晶型由锐钛矿逐渐转变成金红石型,其粒径增大,烧结加剧致使形貌变得更不规则。700℃焙烧产物在紫外光下对罗丹明B具有较佳的光催化降解性能。

The nano-TiO2 with characterization of microcrystalline cellulose was prepared with raw material of TiCI, and microcrystalline cellulose （MCC） as template agent. The formation mechanism of nano-TiO2 was separately discussed with the analysis of transmission electron microscope （ TEM ） , environmental scanning electron microscope （ ESEM ） , fourier transform infrared spectroscopy （ FTIR ）, X-ray diffraction （ XRD ）, thermal gravimetric analysis （ TGA ）. The results show that particle size of the prepared quasi-spherical anatase nano-TiO2 is about 15 nm at sintering temprature of 500 ℃. The nano-TiO2 with a lot of rutile anatase and the red spar-type was prepared at 700℃ and 900℃, respectively. With the increase of the sintering temperature, the crystal type of nano-TiO2 changed gradually from anatase into rutile, and the particle size also increased. Meanwhile, the morphology of nano-TiO2 became more irregular with the sintering going ahead. The product of sintering at 700℃ has a better photo-catalytic degradation performance for rhodamine B under UV light.