吸附相反应技术制备TiO2的结晶过程以及光降解气相甲苯

研究了吸附相反应技术制备纳米TiO2的结晶过程, 并探讨了该过程对TiO2光催化活性的影响. 利用XRD测定了不同温度和时间焙烧后TiO2的晶型以及晶粒粒径的变化, 发现即使焙烧温度高达900 ℃, TiO2仍维持纯锐钛矿晶型. 随着焙烧温度的增加, TiO2的晶粒粒径变化不大, 均在7 nm以下, 在焙烧温度高于700 ℃时, 锐钛矿结晶峰的峰面积随温度增加, 峰面积保持不变. 改变焙烧时间基本不影响TiO2的晶型和晶粒粒径, 因而其光催化活性变化也较小. 光降解气相甲苯实验表明, 700 ℃焙烧后样品的催化活性最高, 且优于商用P25光催化剂.

Crystallization of Nano TiO2 Prepared by Adsorption Phase Reaction Technique and Photo-degradation of Gaseous Toluene

The crystallization of nano TiO2 prepared by adsorption phase reaction technique and the influence of crystallization on photo-catalytic activity of TiO2 were explored. XRD was employed to study the change of crystalline form and gain size of TiO2 under different sintering temperatures and times. The results indicated that there was also pure anatase TiO2 in samples, even when the sintering temperature reached 900 ℃. With increase of sintering temperature, grain size of TiO2 was below 7 nm and changed little. Whereas the peak area of anatase TiO2 increased with sintering temperature and remained unchanged when temperature reached 700 ℃. However change of sintering time influenced little on crystalline form and grain size of TiO2, so its photo-catalytic activity also changed little with sintering time increasing. Photo-degradation of gaseous toluene indicated that the sample sintered under 700 ℃ had the highest photo-catalytic activity and its activity was better than P25.