纳米TiO2低温制备及光催化降解有毒有机污染物

Low-temperature Preparation of Nanometer TiO_2 and Photo-degradation of Toxic Organic Pollutants

通过设计不同的实验方案低温(180℃)制备得到纳米TiO2,并在紫外光(λ≤387nm)照射下利用有机染料罗丹明B(Rhodamine B,RhB)光催化降解为探针反应,以有机污染物降解活性最佳为目的,优选低温制备得到纳米TiO2最佳方案.结果表明以Ti(SO4)2为原料,在低温条件下通过蒸汽热法制得TiO2为最佳方案.对制备高催化活性的纳米TiO2利用透射电子显微镜(TEM),X射线衍射仪(XRD)对其进行了物理特性及光化学性质的初步表征,探讨了纳米TiO2制备时反应温度和反应时间对其粒径大小、晶型转变以及光催化活性的影响.实验结果表明:在以紫外光(λ≤387nm)照射下的探针反应有良好的光催化降解效果为条件,优选低温制备得到纳米TiO2最佳反应温度为180℃,最佳反应时间为12h.通过紫外-可见光谱(UV-vis)、红外光谱(FTIR)和总有机碳(TOC)的测定分析,发现UV/TiO2体系在pH=3.00的条件下,能使RhB发生有效的降解和矿化,矿化率达到93.2%.

Nanometer TiO2 have been prepared at low temperature （ 180 ℃ ） by different methods. The photocatalysis degradation under UV（ ≤387 nm） of organic dye Rhodamine B（RhB） was used as probe reaction to evaluate the best method. For the purpose of the best degradation activity of organic dye, the best method used to prepare TiO2 at low temperature was optimal selected. The results show that the TiO2 prepared at low temperature （ 180 ℃ ） by Ti（ SO4） 2 in the method of steam heating is the best method. The physical and photocatalysis characteristics of high activity TiO2 were carried out using transmission electron mixroscopy （TEM）, and X-ray diffraction （XRD） spectroscopy. In this paper, the influence of the crystalline phase transition, size of particles and of photo-catalytic degradation activity of TiO2 which have been prepared in different temperatures and time were discussed. The resuits show that the best reaction temperature is 180℃ and the best reaction time is 12 h were chosen out by the condition that the probe reaction has good photo-catalytic degradation effect under UV （ ≤ 387 nm）. By UV-vis,FTIR and the measurement of TOC found that RhB can be degraded and mineralized under the TiO2/UV system at pH = 3.00. The mineralized rate of RhB was 93.2%.