Zn掺杂SrTiO_3光催化剂的制备及性能研究

Study on Preparation and Properties of SrTiO_3 Photocatalyst Doped Zn

采用溶胶-凝胶法制备了不同Zn含量掺杂的SrTiO_3光催化剂(Zn-SrTiO_3),通过X射线衍射(XRD)、扫描电子镜显微(SEM)和荧光光谱(PL)对其进行了表征,用亚甲基蓝(MB)光催化降解实验评价了其光催化活性。结果表明,SrTiO_3经Zn掺杂后仍然保持了钙钛矿结构,Zn^(2+)进入SrTiO_3晶格对Sr2+进行了替位掺杂,导致晶格畸变;热处理温度升高,样品发生热团聚;适量的Zn掺杂,能有效降低光生电子和空穴的复合几率,提高SrTiO_3的光催化活性;当掺杂量n(Zn)∶n(Sr)=1.5∶100,热处理温度900℃时制备的样品光催化活性达95.5%,明显优于同等条件下纯SrTiO_3活性58.5%,样品具有较高的光催化活性和良好的稳定性。

Zn-doped SrTiO3 photocatalysts with different Zn contents were prepared by a sol-gel method, and characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and photoluminescence（PL）. The pho- tocatalytic activity were evaluated by photo-degradation of methylene blue（MB）. The results show that Zn-doped Sr- TiO3 keeps a perovskite structure and producing lattice strain due to doping Zn2＋ in the crystal lattice of SrTiO3 and isomorphic substituting Sr2＋ site. The increasing of heat treatment temperature cause thermal reunite of sample particles. Appropriate doping amount of zinc can reduce recombination probability of photogenerated electron-hole pairs and increase the photocatalytic activity of SrTiO3. Meanwhile, the photocatalytic activity of the sample reaches 95.5 % at mole ratio n（Zn） ： n（Sr）= 1.5 ： 100 and the calcined temperature of 900℃,which is obviously higher than 58.5 % of pure SrTiO3. The sample has high catalytic activity and good stability.