La-TiO_2/SiO_2光降解催化剂的制备及性能

Preparation and properties of La-TiO_2/SiO_2 photodegradation catalyst

以钛酸丁酯、正硅酸乙酯和氧化镧为前驱体,采用溶胶-凝胶法制备了不同La掺杂量的负载型催化剂x wt%La-TiO_2/SiO_2(x=0.5~3.0).通过X射线衍射(XRD)、扫描电镜(SEM)、比表面积分析(BET)、傅里叶红外光谱(FT-IR)、X射线光电子能谱(XPS)对样品进行了表征.以罗丹明B(Rh B)为模拟污染物,在紫外光和可见光下研究了不同La的加入量对TiO_2/SiO_2催化剂(其中,n(SiO_2)∶n(TiO_2)=1∶7)光催化效率的影响.结果表明:La的掺杂量为2wt%时,催化性能达到最佳.经过75min紫外光和150min可见光的照射,对Rh B的降解率可分别达到99.2%和71.3%.

The photocatalysts of（x wt%）La-TiO2/SiO2（x=0.5~3.0）were prepared with（Si（OC2 H5）4）,（Ti（OC2 H5）4 and（La2 O3）as precursors via a sol-gel method.The samples were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,specific surface area analyzer（BET）,Fourier transform infrared spectroscopy（FT-IR）and X-ray photoelectron spectroscopy（XPS）,respectively.Using rhodamine B（Rh B）as model pollutant,the effects of the addition of La on photocatalytic efficiency of TiO2/SiO2（the molar ratio of SiO2 to TiO2 was 1∶7）catalyst were investigated under visible light and UV light conditions,respectively.The results showed that the doping amount of La was 2%,the photocatalytic efficiency of the La-TiO2/SiO2 was the best.After 150 min visible light and 75 min UV light irradiation,the degradation rate of Rh B reached 99.2% and 71.3%respectively.