由粉煤灰制备MCM-41及其负载纳米TiO_2的光催化性能研究

Synthesis of MCM-41 from coal ash and photocatalytic performance of MCM-41 doped nano-sized TiO_2

不同TiO_2负载量的TiO_2/MCM-41催化剂通过由粉煤灰制备的MCM-41与钛酸四丁酯溶胶-凝胶制备而成。使用了X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、紫外-可见光谱(UV-Vis)、扫描电镜(SEM)与透射电镜(TEM)对其进行了表征。采用亚甲基蓝的光催化降解反应为模型来评价TiO_2/MCM-41的光催化活性。结果表明:在模拟日光下TiO_2/MCM-41光催化性能远高于同等方法制备的纯纳米TiO_2,且反应属于动力学一级反应。当TiO_2负载质量分数为60%时,TiO_2/MCM-41催化剂催化性能最好且稳定。此外,pH值和温度均可显著影响光催化降解率,pH值和温度越高越有利于提高降解率。

TiO_2/MCM-41 catalyst doped with different TiO_2 content was prepared via Sol-Gel method using MCM-41 which prepared by fly ash and tetrabutyltitanate.The catalysts were characterized by X-ray diffraction（XRD）,Fourier Transform Infrared Spectros（FT-IR）,ultraviolet-visible（UV-Vis）absorption spectroscopy,scanning electron microscope（SEM）and transmission electronmicroscopy（TEM）techniques.The photocatalytic activity of TiO_2/MCM-41 was evaluated by the photocatalytic degradation of methylene blue.The results showed that under simulated sunlight TiO_2/MCM-41 photocatalytic performance is higher than pure TiO_2 prepared by the same way and the degradation followed first-order reaction kinetics.60%TiO_2/MCM-41 exhibited more excellent catalytic performance than others.In addition,pH and temperature can influence the photocatalytic degradation rate significantly and increasing pH and temperature is helpful to increase the degradation rate.