微量Sn^(4+)掺杂TiO_2纤维结构材料的两步法制备及光催化性能  

Two-Step Preparation of TiO_2 Structured Fibers Doped with Trace Sn^(4+) and Its Photocatalytic Property

作　　者：莘俊莲 李建娇[1] 董娜[1] 何方振 苏碧桃[1] 

机构地区：[1]西北师范大学化学化工学院,甘肃兰州730070

出　　处：《精细化工》2015年第7期751-755,788,共6页Fine Chemicals

基　　金：甘肃省科技计划项目(1204GKCA006);国家自然科学基金项目(21174114);教育部"长江学者和创新团队发展计划"创新团队项目(IRT1177);甘肃省自然科学基金项目(1010RJZA024);西北师范大学科技创新项目(nwnu-kjcxgc-03-63)~~

摘　　要：以脱脂棉花纤维为模板,利用浸渍-热转化两步法制备了具有中空结构的微量Sn4+离子(<0.050at.%)掺杂TiO2纤维结构光催化材料(Sn4+/TiO2);通过XRD、SEM、TEM、UV-Vis以及在300 W汞灯和500 W氙灯(模拟太阳光)下对亚甲基蓝(MB)溶液的光催化降解脱色对样品进行了表征。结果表明,利用两步法制备了中空结构的Sn4+/TiO2纤维结构材料;掺入的微量Sn4+均匀分布于TiO2晶格中;TiO2中微量的Sn4+掺杂使TiO2的吸收边发生明显红移,对整个紫外-可见光吸收增强;在紫外、模拟太阳光下显示出好的光催化活性。在模拟太阳光下,Sn4+/TiO2-0.030at.%的光催化活性是TiO2的近4.5倍,而在紫外光下,仅为2.7倍。Sn4+/TiO2良好的光催化性能主要归于少量Sn4+掺入使TiO2的结构多级化、TiO2价-导带间掺杂能级(DE)的形成以及TiO2晶格中活性中心的形成等因素。MB溶液在Sn4+/TiO2上的光催化降解脱色动力学行为比较好地服从一级动力学方程。TiO2 structured fibers doped with trace Sn4＋（ Sn4＋/ TiO2） were prepared via dipping-thermal conversion method（ herein referred to as two-step method） by using absorbent cotton fiber as the template,and the product was characterized by means of X-ray diffraction（ XRD）,scanning electron microscopy（ SEM）,resolution transmission electron microscopy（ TEM）,and ultraviolet-visible spectroscopy（ UV-Vis） techniques. Under the irradiation of Hg and Xe lamps（ simulated sunlight）,the degradation of methylene blue（ MB） on the samples was used as the model reaction to investigate their photocatalytic property. The results show that Sn4 ＋/ TiO2 structured fibers with trace Sn4＋are prepared via the two-step method,and the doping Sn4 ＋ions are well-distributed in TiO2 lattice,which causes a red shift in the absorption edge of TiO2 and a remarkable increase in the intensity of the light adsorption in the range of UV to visible light. And under Hg and Xe lamps,the as-prepared samples show good photocatalytic activity for the degradation of MB solution. The photocatalytic activity of the samples Sn4 ＋/ TiO2-0. 030 at. % is 4. 5 times as that of TiO2 under Xe lamp（ simulated sunlight）,in contrast to its 2. 7 times under Hg lamp（ UV light）. Good photocatalytic property of Sn4 ＋/ TiO2 can beascribed to its multi-structure and the increase of active centers of TiO2 material and doped energy level between valence and conduction bands of TiO2 due to doping Sn4 ＋ions in TiO2. In addition,the photocatalytic degradation of MB solution follows first-order kinetic behavior well on the samples.

关 键 词：Sn^4+/TiO2纤维材料 微量掺杂 模板法 光催化活性 催化与分离提纯技术 

分 类 号：O643[理学—物理化学]