TiO_2光催化降解甲基橙性能的研究

Study of Properties of TiO_2 Photocatalytic Degradation of Methyl Orange

用工业级TiO2(110℃干燥的产品)经焙烧后得到晶粒尺寸为15-30 nm(锐钛矿为主)的二氧化钛纳米光催化剂。用甲基橙降解脱色为模型反应,结合XRD、BET、UV-Vis等表征手段,考察了TiO2焙烧条件与晶粒尺寸和相结构的关系及相应的光催化活性。实验结果表明,锐钛矿的含量为96.7%,晶粒尺寸为24.4 nm时,TiO2光催化降解甲基橙的活性最好。当催化剂用量为0.6 g.L-1,甲基橙溶液质量浓度为20 mg.L-1,pH为3时;光催化反应20 min后,甲基橙的脱色率达到95.60%,CODMn的降解率为72.33%。

Nanometer TiO2 photocatalysts with size range from 15 nm to 30 nm （anatase as the main phase） were prepared with industrial TiO2 （dried at 110℃）. The influence of the calcination conditions on the size and the crystalline phase of the TiO2 crystalline and its photocatalytic activity were studied by means of XRD, BET and UV-Vis technique. These TiO2 samples were also performed as photocatalyst in the degradation and decolorization of methyl orange. The results showed better photocatalytic activity when the percentage of anatase is 96.7% and the size is 24.4 nm. The decolorization rate of methyl orange reached 95.60% and the CODMn degradation rate reached 72.33% under the reaction conditions of the catalyst amount of 0. 6 g· L^-1 , the initial concentration of 20 mg · L^-1 , pH value of 3 and the reaction time of 20 min.