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采用溶胶-凝胶法制备出了锐钛和金红石型两种准晶型纳米TiO2颗粒,ESEM结合XRD显示,锐钛型近似呈球状,粒径约30~40nm;金红石型呈圆棒状,粒径约40~50nm,两种粒径分布均匀,单分散性好,无团聚现象。FT-IR分析表明硬脂肪和其它溶剂加入并不会改变纳米TiO2形成的晶型结构,但煅烧温度对TiO2晶型结构产生较大影响,450~600℃之间产物为锐钛型(最佳温度550℃),650~750℃之间为锐钛型向金红石型转变,750℃时已完全转化成金红石晶型。光催化实验表明,锐钛型催化活性大于金红石型。荧光光谱分析表明,锐钛型纳米TiO2在λ=414nm处有一个特征激发峰,这是因为纳米TiO2中O空位Ti填隙缔合缺陷能级向价带跃迁可能参与了激发光形成过程而导致的。
The anatase and rutile TiO2 nanocrystalline TiO2 particles were prepared by sol-gel method. ESEM and XRD showed that the anatase phase was approximately spherical and the particle size was about 30-40 nm. The rutile type was rod-shaped, About 40 ~ 50nm, two kinds of particle size distribution, good monodispersity, no reunion. FT-IR analysis showed that the addition of hard fats and other solvents did not change the crystal structure of TiO2. However, the calcination temperature had a significant effect on the crystal structure of TiO2. The product between 600 and 600 ° C was anatase Temperature 550 ℃), anatase to rutile transition from 650 ℃ to 750 ℃, which has been completely transformed into rutile crystal at 750 ℃. Photocatalytic experiments show that, anatase catalytic activity than rutile. Fluorescence spectrum analysis showed that anatase TiO2 has a characteristic excitation peak at λ = 414nm, which is due to the potential valence transition of O vacancy Ti interstitial defects in nanostructured TiO2 may be involved in the formation of excitation light of.