ZnO-TiO_2纳米复合材料的制备及光催化性能研究

Preparation and photocatalytic property of ZnO-TiO_2 nanocomposites

以工业级偏钛酸、醋酸锌和尿素为原料,采用一步均匀沉淀法,在600℃、2h条件下,成功制备出ZnO-TiO2纳米复合材料。采用X射线衍射仪(XRD)、透射电镜(TEM)和X射线光电子能谱(XPS)测试手段对反应产物进行了分析。实验结果表明,400℃时,只有锐钛型TiO2的衍射峰;500℃时,开始出现ZnO的衍射峰;600℃以上,开始出现金红石型TiO2和ZnTiO3的衍射峰,并且随着煅烧温度的升高,衍射峰强度逐渐增强。600℃制备的复合粉体结晶完整,无明显团聚现象,颗粒呈球形或类球形,平均粒径在20nm左右。复合粉体表面主要由Zn、Ti、O和C4种元素组成,Zn和Ti元素主要以ZnO、TiO2和Zn-TiO3形式存在。在室内自然光条件下,ZnO-TiO2纳米复合材料可以在一定程度上降解甲基橙。

ZnO-TiO2 nanocomposites were successfully prepared by one-step homogeneous precipitation method with zinc acetate,industrial-grade metatitanic acid and urea as raw materials under 600℃ for 2h.The reaction products were analyzed by X-ray diffraction（XRD）,transmission electron microscope（TEM）and X-ray photoelectron spectroscopy（XPS）.Experimental results showed that only diffraction peaks of anatase TiO2 existed at 400℃,and the diffraction peaks of ZnO occurred at 500℃.When the calcination temperature reached to above 600℃,the diffraction peaks of rutile TiO2 and ZnTiO3 appeared,and the diffraction peaks strength became stronger with the increasing temperature.Nanocomposites synthesized at 600℃ had no obvious agglomeration,and the particles showed the morphology of spherical or near spherical with the average particle size of about 20nm.The surface of the specimen mainly consisted of Zn,Ti,O and C four species elements.Zn and Ti elements mainly existed as ZnO,TiO2 and ZnTiO3.ZnO-TiO2 nanocomposites could degrade methyl orange at a certain extent under light irradiation.