【作者】 雅菁；

【导师】 徐廷献；

【作者基本信息】 天津大学 ， 材料学， 2008， 博士

【摘要】 TiO₂粉体或薄膜光催化剂在紫外光作用下可以杀菌、光催化降解有机污染物,从而达到净化环境的目的,具有广阔的应用前景。采用sol-gel法制备了具有可见光活性的粉体光催化剂Ag/TiO₂、V/TiO₂和La/TiO₂,并通过测试方法对其进行了表征。XPS结果表明在催化剂表面Ag以单质的形式存在,而La以氧化物的形式存在。XRD表明Ag/TiO₂、V/TiO₂和La/TiO₂光催化剂均以锐钛矿的形式存在,其中V离子的引入使衍射发生宽化。光吸收图谱表明Ag/TiO₂、V/TiO₂和La/TiO₂三种光催化剂的光吸收均发生红移,且在可见光区的吸收强度明显高于TiO₂。分别以黑光灯和荧光灯为光源,通过对大肠杆菌的抗菌实验和光催化降解甲基橙溶液,研究了Ag/TiO₂、V/TiO₂和La/TiO₂粉体光催化剂的光催化活性,结果表明三种光催化剂均具有较好的可见光活性。为了降低生产成本,实验以无机盐为原料,采用化学沉淀法和浸渍法相结合制备了具有可见光活性的N、金属离子双掺杂TiO₂粉体,光催化实验表明:双掺杂TiO₂粉体在可见光下具有较好的光催化活性。由于薄膜材料更具有发展前景,本实验对TiO₂薄膜的抗菌和降解有机污染物活性进行了研究。通过稀土元素掺杂,制备了La/TiO₂和Ce/TiO₂薄膜光催化剂,此光催化剂在可见光下能够有效杀死大肠杆菌和降解甲基橙溶液。钙钛矿型氧化物是另一类新型可见光活性光催化剂,实验采用柠檬酸络合法制备了形状均匀的纳米LaCoO₃及其复合钙钛矿型氧化物,并对其光催化活性及抗菌性能进行了分析。结果表明,随着LaCoO₃粉体粒径的增大及Cu掺入量的减少,其光催化活性和抗菌性都降低。各LaBO₃化合物粉体的光催化活性和抗菌性的变化趋势为:LaCoO₃>LaFeO3>LaMnO3。更多还原

【Abstract】 TiO₂ powder and film could purify circumstance due to their antibacterial action and photocatalytic degradation of organic polluted compounds under the radiation of UV. So TiO₂ photocatalyst has a variety of application prospects in the field of environmental protection.Ag/TiO₂, V/TiO₂ and La/TiO₂ powder photocatalysts with visible-light activities were prepared by sol-gel method. And, the so-prepared photocatalysts were characterized by XPS, XRD and UV-vis. XPS showed that Ag existed as metal, whereas La existed as oxide. The crystalline structure of Ag/TiO₂, V/TiO₂ or La/TiO₂ was all anastase, and doping V5+ ion in TiO₂ resulted in the peak shape of X-ray diffraction broadened. UV-vis absorbance spectra of Ag/TiO₂, V/TiO₂ or La/TiO₂ showed that absorption limits bathochromic shift occur in the doped photocatalysts. Moreover, the absorbance intensity of Ag/TiO₂, V/TiO₂ or La/TiO₂ was higher than that of pure TiO₂ under visible region.With black light lamp or fluorescent lamp as light source, the antibacterial experiments and photodegradation of methyl orange solution were carried out to investigate the visible-light activity of Ag/TiO₂, V/TiO₂ and La/TiO₂ powder. From the results, it could be found all the three kinds of photocatalysts took on good visible-light activity.In order to reduce the cost of TiO₂ powder, the inorganic salt was used as resource to prepare co-doped TiO₂ powder by the chemical precipitation and impregnating methods. The photocatalytic experiment results showed that the co-doped TiO₂ photocatalysts have good photocatalytic activity under visible light irradiation.Since film materials have more application prospects than powder, TiO₂ films were prepared in this study. The antibacterial properties and photodegradation of polluted organic compound were analyzed. By doping of rare earth element, the La/TiO₂ and Ce/TiO₂ film photocatalysts were prepared by sol-gel method. These La/TiO₂ or Ce/TiO₂ films can kill bacteria and degrade methyl orange under visible light irradiation.Perovskite type oxides are a new-style photocatalysts with visible-light activities. In our experiment, the LaCoO₃ and its multicomponent perovskite type oxides with uniform size were prepared by citric acid complex method. Simultaneity, the photocatalytic activity and antibacterial performance of the powders were analyzed. The results showed that the photocatalytic activity and antibacterial performance were decrease with the increase of the particle size and the decrease of Cu content. And, in LaBO₃ multicomponent perovskite type oxides, the trend of photocatalytic activity and antibacterial performance were LaCoO₃>LaFeO3>LaMnO3.更多还原