【摘要】 用共沉淀法和溶胶-凝胶法制备了La掺杂TiO2光催化剂(La3+-TiO2),并以罗丹明B为模型反应物,进行了光催化降解实验.结果发现,共沉淀法制备的La3+-TiO2具有较高的光催化活性,当掺La量为1.0%、于800℃煅烧2 h时获得的催化剂活性最佳.用X射线衍射、N2吸附、扫描电镜和电子探针等手段测定了两种方法制备的典型样品的结构和粒度分布.两种方法制备的催化剂都是含有锐钛矿和金红石型TiO2的混合晶体,但共沉淀法制备的催化剂具有较高的锐钛矿含量、较大的晶粒和大孔/介孔的多级孔结构,这是其具有较高光催化活性的主要原因.更多还原

【Abstract】 Lanthanum-doped TiO2,photocatalysts La3+-TiO2,were prepared by coprecipitation and sol-gel methods.Rhodamine B was used as the reactant to evaluate the photocatalytic activity of the catalyst samples.The results showed that the La3+-TiO2 catalyst prepared by coprecipitation exhibited obviously higher photocatalytic activity.The optimum preparation conditions of coprecipitation were lanthanum ions doped of 1%,calcination temperature of 800 ℃,and calcination time of 2 h.The best catalyst samples were characterized by X-ray diffraction,N2 adsorption-desorption measurement,scanning electron microscopy,and electron probe microanalyses.The two photocatalysts prepared by coprecipitation and sol-gel both had mixed crystal structure of anatase and rutile,and the anatase contents were 80% and 70%,respectively.The higher photocatalytic activity of the La3+-TiO2 catalyst prepared by coprecipitation was mainly attributed to its more regular structure of anatase,larger crystal size,and hierarchical macro/mesoporous structure.更多还原