可见光活性负载型Fe_2O_3/TiO_2光催化剂的制备

PREPARATION OF Fe_2O_3/TiO_2 SUPPORTED PHOTOCATALYST WITH VISIBLE LIGHT ACTIVITY

以FeCl3·6H2O和TiOSO4为原料,尿素为沉淀剂,采用均匀共沉淀法制备了Fe3+掺杂的纳米TiO2粉体,并通过X射线衍射、透射电镜分析及观察粉体的相结构、形貌和粒径。以甲基橙溶液为降解对象,考察了掺杂后的粉体在紫外和可见光作用下的光催化性能并对其机理进行了探讨。结果表明:Fe3+部分固溶于TiO2的晶格;当Fe3+掺杂量<0.8%(摩尔分数,下同)时,随铁离子掺入量的增加,TiO2的光催化性能提高;当Fe3+掺杂量为0.8%时,复合粉体的光催化性能提高15%以上;当Fe3+掺杂量>0.8%时,随铁离子掺入量的增加,TiO2的光催化性能降低,而当Fe3+掺杂量>1.2%时,粉体的光催化性能受到抑制,低于纯TiO2粉体。

The composite photocatalyst of nanocrystalline TiO2 doped with Fe^3＋ was prepared by the homogeneous co-precipitation method and using FeCl3·6H2O and TiOSO4 as precursors and urea as precipitant. The structures and morphology of the photocatalyst were characterized by X-ray diffraction and transmission electron microscopy. The photocatalystic activity under visible and ultra- violet light was evaluated by photocatalytic degradation of methyl orange. The reaction mechanism also was studied. The experimental results show that the photocatalytic activities of TiO2 can be improved by doping 0.8%-1.2% （in mole, the same below） Fe^3＋. The optimum doping content of Fe^3＋ is 0.8%, and the photocatalytic activity of the photocatalyst increases more than 15% whether under visible or ultraviolet light. With the increase of Fe^3＋ content, the photocatalytic activity decreases. When the content of Fe^3＋ exceeds 1.2%, the photocatalytic activity of the material is less than that of pure TiO2.