萃取沉淀法制备纳米TiO2及其对活性红M-3BE的降解研究

采用萃取沉淀法制备TiO2，并以其作为催化剂降解活性红M-3BE。通过正交实验考察了催化剂用量、pH值、光照时间对活性红M-3BE光催化脱色的影响；研究了活性红M-3BE的初始浓度以及Na⁺、K⁺、Cl^－和SO₄^2－等对活性红M-3BE光催化降解的影响。结果表明，适宜的反应条件为：pH=4, 催化剂用量0.8 g/L, 反应时间80 min。在此条件下脱色率为　89%，COD去除率为71%。在酸性条件下，脱色效果优于碱性条件，并且盐离子对脱色率几乎无影响。而在碱性条件下，盐离子对脱色率影响较大。温度对光降解反应影响很小，可以忽略。 降解过程遵循准一级动力学方程。

Preparation of nanometer titania by extraction-precipitation and its application in degradation of reactive red M-3BE

Photocatalytic degradation of reactive red M-3BE over nanometer titania prepared by extraction-precipitation was studied. Effects of the catalyst amount , illumination time and pH on photocatalytic decolorization of reactive red M-3BE was investigated, as well as effect of initial reactive red M-3BE concentration and incorporation of Na⁺, Cl^－, K⁺, SO₄^2－ on the degradation. The result showed that the appropriate reaction condition is : pH=4, catalyst amount=0.8 g/L, illumination time= 80 min , under which decolorization efficiency of 89% and COD removal efficiency of 71% is attainable. Alkalinity favours the decolorization rather than acidity. Incorporation of Na⁺, Cl^－, K⁺, SO₄^2－ greatly decreases decolorization efficiency under alkaline condition while no remarkable influence was observed under acidic condition. Effect of temperature on the reaction is negligible. Kinetics of the decolorization reaction can be expressed by a first-order equation.