掺铁纳米TiO2光催化降解乐果的实验研究

以钛酸四丁酯CH3(CH2)3O]4Ti]为钛源，硝酸铁Fe(NO3)3×9H2O]为改性剂，采用溶胶-凝胶法合成了掺铁纳米TiO2催化剂. 纳米TiO2的最佳掺铁量为0.05%，最佳煅烧温度为500℃. 采用X射线衍射、热重-差热、紫外-可见光谱对其结构进行了表征. 结果表明，500℃时煅烧的掺铁0.05%的TiO2为锐钛矿型，晶粒粒径为17.5 nm，其光谱吸收边带发生了红移，吸收强度增大. 对50 mg/L氧化乐果溶液的光催化降解实验表明，当光催化剂的最佳用量为0.2 g/L、溶液pH为8.6时，250 W高压汞灯照射2.5 h，乐果的降解率达到了85.23%，降解反应符合一级动力学方程.

Photocatalytic Degradation of Omethoate with Iron Doped Nanometer TiO_2

Titanium dioxide sol was synthesized by sol-gel method with adulteration of Fe(NO_3)_3·9H_2O. The samples were characterized by XRD, DTA-TG and UV-Vis. The results show that the diameter of particles is 17.5 nm and pure anatase. From the UV-Vis spectra the absorption edge of iron-doped titania has a red shift and the absorption intensities are increased. The degradation rate of omethoate reaches 85.23% when the dosage of photocatalyst is optimally 0.2 g/L, pH=8.6 and 2.5 h illumination with high-voltage mercury lamp. The photocatalytic degradation kinetics follows the pseudo-first order reaction.