TiO_2/HZSM-5的制备及光催化性能的表征

Preparation and characterization of HZSM-5 supported TiO_2 photocatalyst

以钛酸四丁酯为钛源,采用溶胶-凝胶法在HZSM-5分子筛表面合成TiO2前驱体,程序升温处理制得TiO2/HZSM-5负载型光催化剂。采用X射线衍射、扫描电镜、傅里叶变换红外光谱、X射线光电子能谱对光催化剂晶相结构、表面形貌及化学组成进行了表征。结果表明,HZSM-5可提高TiO2分散性能,降低TiO2晶粒的尺寸。TiO2/HZSM-5中的Ti都以TiO2形式存在,没有Ti—O—Si键生成。甲基橙溶液的光催化降解结果表明,负载后提高了TiO2对甲基橙溶液的光催化降解活性。TiO2的质量分数为30%,400℃下煅烧2h时的催化剂光催化性能最好。

HZSM-5 supported TiO2 photocatalysts（TiO2/HZSM-5） were prepared by a sol-gel method from Ti（OBu）4.The photocatalysts were characterized by X-ray diffraction,Fourier transform infrared spectroscopy,scanning electron microscopy,X-ray photoelectron spectroscopy analysis.The results indicated that HZSM-5 could improve the dispersion of TiO2,decrease the aggregation size,and inhibit the phase transformation of TiO2 from anatase to rutile.Ti—O—Si bonds were not formed between the HZSM-5 bulk and the supported TiO2.The titanium was in the oxidation state of Ti^4＋,and the oxygen was in the form of O^2-in TiO2 and also in SiO2.The photocatalytic activity was investigated by using methyl orange degradation under UV irradiation.The results showed that TiO2/HZSM-5 photocatalyst with a suitable TiO2 content exhibited higher activity than pure TiO2.The optimum photocatalytic activity for the samples with 30% TiO2 was obtained after being calcinated at 400℃ for 2h.