NaF改性纳米TiO_2粉体光催化性能  

Photocatalytic Performance of Nanometer Titanium Dioxide With Sodium Fluorid Doping

作　　者：孙彤[1] 翟玉春[1] 马培华[1] 

机构地区：[1]东北大学材料与冶金学院

出　　处：《石油化工高等学校学报》2006年第2期5-8,共4页Journal of Petrochemical Universities

基　　金：国家自然科学基金资助项目(5007014)

摘　　要：对P25型纳米TiO2粉体光催化降解罗丹明B的光催化过程的动力学分析表明,光催化降解为一级反应。以反应速率常数为评价指标,确定了光催化降解的最优条件为:罗丹明B初始质量浓度为10 mg/L,灯与液面距离6 cm,液层厚度6 cm,TiO2加入量0.4 g/L。采用浸渍法制备了NaF掺杂改性的P25型纳米TiO2粉体。焙烧使样品的晶体颗粒长大,会导致纳米粉体的量子尺寸效应下降,NaF掺杂改性使F-进入TiO2晶格,取代了O位,从而造成了晶格畸变,使光生载流子增多,抵消了纳米粉体的量子尺寸效应下降的影响,表现为样品光催化活性提高。NaF最佳掺杂质量分数为3%。NaF掺杂量过多时,光生载流子产生量较大,纳米颗粒表面电子和空穴相邻较近,电子和空穴的复合几率增加,样品光催化性能下降。The dynamics analysis on photocatalytic process of degradating Rhodarnine B with the powder of P25 nanometer titanium dioxide shows that photocatalytic oxidation is first order. According to reaction velocity constants, the optimum initial conditions of degradation were detemlined. It is 10 mg/L of Rhodamine B, 6 cm between light and solution, 6 cm thickness of solution and 0.4 g/ L of titanium dioxide. The powder of P25＇ nanometer titanium dioxide with sodium fluorid was prepared by doping method. The crystal grains grow up because of burning and the quanta sizes function of nanometer powders decrease. After sodium fluorid doping, the fluorin ions are entered into the crystal lattice of titanium dioxide and oxygen are replaced, so the crystal lattices are contorted and the number of light produced electrons and cavities is increased, the quanta sizes function of nanometer powders is counteracted and the photocatalytic performance of the sample is increased. The optimum mass fraction of sodium fluorid is 3 %. When the amount of sodium fluorid doped is overmuch, the light - produced electrons and cavities are overmuch, too. The distance of electrons and cavities on the surface of nanometer powders is small, then the compounding probability of electrons and cavities inereases and the photocatalytic performance of the ,sample decreases.

关 键 词：P25型纳米TiO2 光催化 罗丹明B NaF改性 

分 类 号：O643[理学—物理化学] X703[理学—化学]