【作者】 黄美莹；

【导师】 赵晓旭；

【作者基本信息】 哈尔滨理工大学 ， 材料物理与化学， 2007， 硕士

【摘要】 本文系统研究六种金属离子掺杂TiO₂薄膜的掺杂机理,并结合X-射线衍射（XRD）以及扫描电镜（SEM）形貌分析,分别研究了掺杂离子的种类、掺杂浓度、离子半径、离子价态、离子电荷、离子稳定氧化态的电子亲和势以及氧化物的生成焓与纳米TiO₂薄膜的光催化性能之间的关系。以钛酸四丁酯和无水乙醇为原料,加硝酸盐溶液引入金属离子,采用溶胶-凝胶法和浸渍-提拉法在玻璃表面施涂膜层,镀膜速度控制在2³mm/min。通过热处理以后,得到均匀透明、颗粒分布均匀的掺杂纳米TiO₂薄膜,并且薄膜相结构均为锐钛矿相和金红石相,每次制备出的纳米粒子粒径稳定在30⁵0nm。光催化降解甲基橙试验结果表明,La³⁺、Ce³⁺、Fe³⁺、Ni²⁺、Cu²⁺的掺杂明显提高了TiO₂的光催化活性,其中Fe³⁺掺杂的TiO₂薄膜光催化降解率最高,达到90.01%,而Zn²⁺的掺杂则在一定程度上降低了TiO₂光催化降解甲基橙的能力,本试验条件下光催化降解能力依次为Fe³⁺>La³⁺>Ni²⁺>Cu²⁺>Ce³⁺>Zn²⁺。离子掺杂浓度与光催化性能试验结果表明,随着掺杂Fe³⁺浓度的增加光催化活性提高,随着掺杂La³⁺浓度的增加光催化活性下降;Cu²⁺、Ce³⁺的最佳掺杂浓度为5%,Ni²⁺的最佳掺杂浓度为3%;随着光照时间的增加,掺杂上述离子均使TiO₂的降解率增大。经过多次试验和各种测试结果证明,除了Ce³⁺外,掺杂离子后随着粒径的减少,锐钛矿相的含量呈递增的趋势,光催化活性也越来越好。在掺杂Fe³⁺浓度为5%时粒径较小,达到38.23nm,光催化活性较高;而掺杂Zn²⁺时粒径较大,为41.86nm,光催化活性较低。此外,离子电荷与半径的比值q/r与催化活性的变化规律基本相同,q/r值越大即离子的得电子能力越强。掺杂元素稳定氧化态电子亲和势与离子半径的比值Ea/r与催化活性之间有很好的一致性,掺杂元素的稳定氧化态对电子的亲和能力越大,催化活性越高;第一电离能与光催化活性的关系不大,而MO_X /TiO₂光催化性能与对应金属氧化物生成焓间具有较好的相关性,即氧化物生成焓越小,光催化活性越好;除Fe³⁺外,氧化物生成焓越大,光催化活性越差。更多还原

【Abstract】 In this thesis, the doping mechanism of six kinds of metallic ions-doped TiO₂ film was systematically researched. The relationships between the ion species, the ion concentration, the ion radius, the ion valence, the electron charge, the electron affinity potential under stable oxidation state, the formation enthalpy of oxide and the photocatalytic activity of nanometer TiO₂ film were respectively studied in terms of the X-ray diffraction and the pattern analysis with scanning electron microscope.Acted as raw materials for the tetrabutylester titanic and the absolute ethyl alcohol, metal irons were introduced by nitrate solution. TiO₂ film was daubed on the surface of glass by sol-gel method and dipping-hang method with a coating speed 2³mm/min. Transparent and homogeneous TiO₂ film was obtained after heat-treating and the phase structure of this film was anatase and rutile. The mean particle size of nano particles prepared was 30⁵0nm every time. It was indicated from the results of photocatalytic degradation tests upon the methyl orange that the photocatalytic activity of TiO₂ was increased obviously by doped La³⁺, Ce³⁺, Fe³⁺, Ni²⁺ and Cu²⁺, especially the photocatalytic activity coefficient of that doped with Fe³⁺ was 90.01% which was the highest one, however, the activity was decreased by doped Zn²⁺. The photocatalytic activity under the given experiment condition was: Fe³⁺ > La³⁺ > Ni²⁺ > Cu²⁺ > Ce³⁺ > Zn²⁺. It was indicated from the results of tests on the relationship between the content of doped ions and the photocatalytic activity that the photocatalytic activity increased with the increasing of content of doped Fe³⁺ and decreased with the increasing of content of doped La³⁺; the optimum content of Cu²⁺ and Ce³⁺ was 5%, and that of Ni²⁺ was 3%; the photocatalytic activity was increased by all doped ions with the increasing of light time. It was proved from results of many tests that the content of anatase phase and the photocatalytic activity increased with the decreasing of particle size caused by the doped ions except for Ce³⁺. The minimum particle size of TiO₂ was 38.23nm and the photocatalytic activity was preferable when the content of doped Fe³⁺ was 5%, however, when doped with Zn²⁺, the particle size was 41.86nm and the photocatalytic activity was minor. Besides, the varying regularity of the ion charge-radius ratio q/r was similar to that of photocatalytic activity, the more the ratio q/r, the more the ability of capturing electron. The ratio of eletron affinity potential under stable oxidation state for the doped ions and ion radius （Ea/r） was in good consistence with the photocatalytic activity, the more the electron affinity potential under stable oxidation state for the doped ions, the higher the photocatalytic activity; there was little relationship between the initial ionization potential and the photocatalytic activity, but better correlation between the formation enthalpy of the corresponding metallic oxide and the photocatalytic activity of MO_X /TiO₂, the less the formation enthalpy of oxide, the higher the photocatalytic activity, and vice versa except for Fe³⁺.更多还原