铁、铬离子掺杂对TiO2薄膜光催化活性的影响

采用溶胶-凝胶法在釉面砖表面制备了均匀的TiO2薄膜,并研究了铁、铬离子掺杂对TiO2光催化性能影响。对罗丹明B的光降解实验表明,适量的铁、铬离子掺杂均可提高TiO2薄膜的光催化活性,铁离子的掺杂效果明显高于铬离子,而铬离子的掺杂方式影响TiO2薄膜的光催化活性,这主要基于它们不同的掺杂机理。     

Y^3＋掺杂TiO2复合粒子的光催化活性研究

以钛酸丁酯和氧化钇为原料,采用溶胶－凝胶法研究了Ｙ＾３＋掺杂对ＴｉＯ２光催化活性的影响,通过红外光谱（ＩＲ）分析了ＴｉＯ２复合粒子的结构,结果表明：Ｙ＾３＋掺杂能够显著提高ＴｉＯ２粒子的光催化活性,当掺杂比为１００∶１．５（Ｙ＾３＋外加１．５％）时光催化活性最高,分析了Ｙ＾３＋掺杂ＴｉＯ２粒子光催化活性提高的原因。     

溶胶—凝胶法制备TiO2／Pt／glass纳米薄膜及其光电催化性能

本文采用Ｓｏｌ－ｇｅｌ法制备了ＴｉＯ２／Ｐｔ／ｇｌａｓｓ纳米光催化薄膜，并进行了结构和乐电催化性能的测试。薄膜对染料溶液的光电催化降解结果表明，当输入正向偏压后，ＴｉＯ２／Ｐｔ／ｇｌａｓｓ薄膜的光催化性能有一定提高，且随着偏压增大而增强。同时，薄膜的中间层Ｐｔ及光源强度对薄膜的光电催化活性也有较大影响。     

离子束辅助沉积制备TiO_2-Nb_2O_5氧敏薄膜

采用离子束辅助沉积方法在Ａｌ２Ｏ３陶瓷衬底上制备了ＴｉＯ２Ｎｂ２Ｏ５氧敏薄膜。考察了薄膜组分比及退火温度对薄膜氧敏特性和结构的影响。电阻氧分压特性测试结果表明，纯Ｎｂ２Ｏ５薄膜的氧敏特性优于纯ＴｉＯ２薄膜；掺入少量的Ｔｉ可使Ｎｂ２Ｏ５薄膜的氧敏特性提高，以５ｍｏｌ％ＴｉＯ２掺杂的Ｎｂ２Ｏ５薄膜最佳；过量掺杂则使Ｎｂ２Ｏ５薄膜的氧敏特性明显变差。在５ｍｏｌ％ＴｉＯ２Ｎｂ２Ｏ５薄膜中再掺入少量的Ｐｔ（０３％０５％）可使其氧敏特性更好，而且其响应时间大大缩短。Ｘ射线衍射谱（ＸＲＤ）和Ｘ射线光电子谱（ＸＰＳ）分析表明，在退火后的ＴｉＯ２Ｎｂ２Ｏ５薄膜中Ｎｂ２Ｏ５为单斜（Ｍｆｏｒｍ）结晶相，而掺杂的Ｔｉ以非晶的ＴｉＯ２形式存在，即使在高达３４ｍｏｌ％ＴｉＯ２Ｎｂ２Ｏ５薄膜中也不例外。纯ＴｉＯ２膜为金红石结构。不同退火温度（９００１１０００Ｃ）对薄膜的氧敏特性和结构无明显影响。     

离子束辅助沉积制备TiO2—Nb2OT氧敏薄膜

采用离子束辅助沉积方法在Ａｌ２Ｏ３陶瓷衬底上制备了ＴｉＯ２－Ｎｂ２Ｏ５的氧敏薄膜。考察了薄膜组分比及退火温度对薄膜氧敏特性和结果的影响。电阻－氧分压特性测试结果表明，纯Ｎｂ２Ｏ５薄膜的氧敏特性优于纯ＴｉＯ２薄膜；掺入少量的Ｔｉ可使Ｎｂ２Ｏ５薄膜的氧敏特性提高，以５ｍｏｌ％ＴｉＯ２掺杂的Ｎｂ２Ｏ５薄膜最佳；     

TiO2光催化薄膜的XPS研究

利用ＴｉＯ２溶胶通过浸涂技术在钠钙玻璃表面制备了ＴｉＯ２光催化薄膜,根据Ｘ射线光电子能谱（ＸＰＳ）对薄膜进行了表征。结果表明,薄膜中除含有＋４价Ｔｉ的氧化物外,还有一定量的＋３和＋２价Ｔｉ的氧化物。结合有机基团燃烧的还原作用、玻璃中钠与钙离子的扩散和Ａｒ离子刻蚀,对这种现象作了讨论。Ｏｌｓ的高分辨谱比文献报道的更复杂。元素在薄膜内层的分布更均匀,从表面到内层,Ｏ和Ｔｉ元素的含量明显增加,而Ｃ、Ｎａ     

离子掺杂对纳米TiO2薄膜光催化活性的影响研究

研究了Ag 、Cu2 、La3 、Ni2 及W6 5种离子掺杂对釉面瓷砖表面TiO2薄膜光催化活性的影响,并采用XRD和UV-VIS检测技术对所制备的TiO2薄膜材料进行了表征.结果表明,掺杂离子能有效提高TiO2薄膜的光催化活性,且离子的掺杂存在一个最佳浓度.UV-VIS及XRD衍射发现,掺杂后的纳米TiO2薄膜有不同程度的吸收光谱带边蓝移及粒径减小的现象,具有量子尺寸效应.     

掺杂TiO_2对C_4A_3形成及水化性能的影响

研究了掺杂 ＴｉＯ２对Ｃ２Ａ３Ｓ矿物的形成及水化性能的影响在１３００℃保温１ｈ, ＴｉＯ２稳 定过渡产物ＣＡ的作用使Ｃ４Ａ３Ｓ的形成速度降低;在１３００℃保温３ｈ,适量的 ＴｉＯ２增加 Ｃ４Ａ３Ｓ的 形成量;ＴｉＯ２的含量过高,使Ｃ４Ａ３Ｓ的形成量减少并出现 ＣＴ（ＣａＴｉＯ３）．掺杂ＴｉＯ２使Ｃ４Ａ３Ｓ 以四方晶系的结构存在掺杂提高了Ｃ４Ａ３Ｓ的水化反应活性,其原因是晶体结构的畸变     

TiO2-SiO2复合半导体气凝胶制备及光催化活性研究

ＴｉＯ２－ＳｉＯ２复合半导体气交是一种新型纳米光催化氧化剂。本文以正硅酸乙酯、钛酸丁酯为原料,用溶胶－凝胶法经超临界干燥制备出了ＴｉＯ２－ＳｉＯ２复合半导体气凝胶。研究了ＴｉＯ２：ＳｉＯ２不同配比对溶胶－凝胶过程的影响;用ＢＥＴ、ＸＲＤ、ＳＥＭ、ＴＥＭ等测试方法对其结构进行了表征;以苯酚为探针考察了ＴｉＯ２－ＳｉＯ２复合半导体气凝胶的光催化氧化活性,并与普通锐钛矿型钛白粉光催化剂进行了对比结果表明     

纳米TiO2的光化学特性及其在环境科学中的应用

纳米ＴｉＯ２是一种优异的光电功能材料。介绍了其奇特的表面结构、优异的光化学特性及其光催化作用的机理,并概述了纳米ＴｉＯ２在环境科学中有机污染物的光催化降解、重金属离子的光催化还原及光催化杀菌等方面的应用。     

稀土掺杂TiO2光催化材料的制备和性能

采用溶胶-凝胶法制备了5种稀土（Pr、Nd、Sm,Eu、Dy）掺杂TiO2光催化薄膜,研究了稀土掺杂量,镀膜层数、烧结温度和烧结时间对光催化活性的影响．结果表明,各因素对材料的催化活性均存在一最佳值．薄膜中仅含TiO2而未见稀土氧化物,除掺锴TiO2薄膜完全由金红石相组成外,其余均由锐钛矿相和金红石相的混晶组成,其中金红石相所占比例较大,薄膜表面均存在大量缺陷;稀土掺杂TiO2薄膜对罗丹明B的光降解率可达89．3％．稀土掺杂TiO2显著提高了TiO2对可见光的响应能力,提高了材料的光催化活性．     

非金属掺杂TiO2催化剂的制备及可见光诱导活性

通过金属及非金属离子掺杂改性、离子注入以及染料光敏化等方法可以将只能紫外光激发的TiO2光催化反应红移到可见光区域进行,近年来国内外在非金属掺杂TiO2可见光催化剂研究取得了积极进展。本文主要对N掺杂和C掺杂TiO2的制备方法进行了介绍,同时对其掺杂的非金属存在形态及掺杂机理作了理论分析。     

Photocatalytic activities of Ion doped TiO2 thin films when prepared on different substrates

Pure and ion doped TiO₂ thin films were prepared by sol-gel dip coating process on metallic and non-metallic substrates. Test metal ion concentration ranged from 0.000002 to 0.4 at.%. The resulting films were annealed in air and characterized by optical spectroscopy and X-ray diffraction. The photodegradation of methyl orange under UV irradiation by pristine and ion-doped TiO₂ films was quantified in a photocatalytic reactor developed in this study. In general, both doped and undoped TiO₂ crystals appeared in anatase phase and the photocatalytic activities of the TiO₂ thin films varied with substrates, calcination temperature, doping ions and their concentrations. The best calcination temperature for different substrates ranged from 450 to 580 °C. Films prepared on the metallic substrates resulted in higher photocatalytic activities, while ion doping lowered their efficiencies. On the contrary, for non-metallic substrates except ceramic the photocatalytic efficiencies of undoped films were much lower (< 30%), while ion doping was shown to increase the photocatalytic efficiencies remarkably in some cases, e.g., Cr³⁺ with the tile substrate. Overall, ion doping affected the photocatalytic efficiency of TiO₂ films, and an optimal doping concentration of between 0.0002 and 0.002 at.%, close to an estimate by the Debye length equation, resulted in the highest efficiency for most substrates.     

Preparation of re-usable photocatalytic filter for degradation of Malachite Green dye under UV and vis-irradiation

Sn(4+) doped and undoped nano-TiO(2) particles easily dispersed in water were synthesized without using organic solvent by hydrothermal process. Nanostructure-TiO(2) based thin films were prepared on flyswatter substrate, made with stainless steel, by dip-coating technique. The structure, surface and optical properties of the particles and thin films were characterized by element analysis and XRD, BET, SEM and UV/vis/NIR techniques. The photocatalytic performance of the films were tested for degradation of Malachite Green dye in solution under UV and vis-lights. The results showed that the coated flyswatter has a very high photocatalytic performance for the photodegradation of Malachite Green irradiated with UV and vis-lights. The results also proved that the hydrothermally synthesized nano-TiO(2) particles are fully anatase crystalline form and are easily dispersed in water, the coated surfaces are hydrophilic, and the doping of transition metal ion efficiently improved the degradation performance of TiO(2)-coated flyswatter. The photocatalytic performances determined at both irradiation conditions were very good and were almost similar to each other for Sn(4+) doped TiO(2)-coated flyswatter and it can be repeatedly used with increasing photocatalytic activity compared to undoped TiO(2)-coated flyswatter.     

Fe2O3/TiO2和ZnO/TiO2纳米颗粒薄膜的亲水性能和光催化性能的研究

采用溶胶-凝胶法在玻璃上制备了锐钛矿型TiO_2和过渡金属铁、锌离子掺杂的TiO_2薄膜,并通过XRD、XPS、AFM表征了合成的薄膜。结果表明铁和锌离子掺入后,TiO_2薄膜变的更加致密。铁离子和锌离子分别以Fe_2O_3和ZnO的形式存在,在紫外光照射下,TiO_2薄膜表现明显的亲水性,金属离子掺杂的TiO_2薄膜,亲水性能明显增强,铁离子掺入对光催化降解甲基橙有一定的抑制作用;少量的锌离子掺入对光催化降解甲基橙有促进作用,锌离子掺入量增大后,效果并不明显。     

双微乳液法制备掺杂Fe~(3+)的纳米TiO_2及其光催化性能

为了研究双微乳液法在制备纳米级光催化剂的应用,以TiCl4和NH3.H2O为原料,采用十六烷基三甲基溴化铵-正丁醇-环己烷-水微乳体系制备Fe3+掺杂纳米TiO2,对粉末的晶体结构进行X射线衍射表征,并以其对p-甲酚的降解考察其光催化活性。结果表明,在较小的掺杂量时,Fe3+掺杂量的提高可以提高TiO2的光催化活性,进一步提高掺杂量将引起光催化活性的降低;掺杂Fe3+可导致纳米TiO2的粒径减小;Fe3+的半径较小以及Fe2O3的熔点较低均有利于TiO2从锐钛矿向金红石的相变;当Fe3+掺杂摩尔分数为0.06%,煅烧温度为550℃时,纳米TiO2的光催化活性最高,此时形成TiO2的锐钛矿和金红石相的混晶;乳液中含水量也会影响晶相的组成和粒径大小,随着含水量增加产物中出现了一定比例的金红石相。     

泡沫镍负载TiO2和TiO2/Al2O3薄膜的光催化性能研究

以泡沫镍为载体，Al2O3作为过渡中间层，用溶胶-凝胶法在泡沫镍上负载锐钛矿相的TiO2薄膜，制成泡沫金属基的TiO2和TiO2／Al2O3光催化剂，利用XRD和FE-SEM等测试手段对其性质进行表征，用乙醛气体的光催化降解测试其活性．研究表明：泡沫镍负载的TiO2和TiO2／Al2O3薄膜具有良好的光催化活性，特别是TiO2／Al2O3薄膜具有更高的催化活性．这是由于负载的Al2O3过渡中间层增大了载体的比表面积，具有吸附浓缩作用，同时也增加了负载光催化剂的活性位数量．实验表明：TiO2／Al2O3薄膜的光催化活性和稳定性较单一的TiO2薄膜有非常显著的提高．     

Photocatalytic degradation of monocrotophos pesticide--an endocrine disruptor by magnesium doped titania

Mg-doped TiO(2) with different Mg concentrations were prepared using sol-gel method and characterized by XRD, UV-visible, XPS, SEM and FT-IR. The XRD results revealed that Mg(2+) goes into the TiO(2) lattice. SEM images of the doped and pure TiO(2) indicated that there is a smaller particle size for the doped catalyst compared to that of the pure TiO(2). UV-visible absorption spectra indicated that upon doping with Mg(2+) ion, the catalyst exhibits absorption in visible region. FT-IR and XPS spectra demonstrated that the presence of Mg(2+) ion in the TiO(2) lattice as substitutional dopant. Photocatalytic activity of doped TiO(2) has been evaluated by degradation of the monocrotophos (MCP) pesticide. The effect of solution pH, catalyst dosage and initial concentration of MCP on the photocatalytic activity of Mg-doped TiO(2) with different loadings was studied. It was observed that the rate of degradation of MCP over Mg-doped TiO(2) is better than Pure TiO(2) and Degussa P-25.     

Ag/TiO2薄膜结构和光催化性能研究

采用溶胶-凝胶技术制备了Ag掺杂的TiO2薄膜.用XRD、氮吸附法、UV-VIS-NIR分光光度计以及XPS对Ag掺杂后TiO2薄膜结构的变化进行了分析;用分光光学法通过在紫外光照下分解亚甲基蓝的实验比较了TiO2薄膜与Ag/TiO2薄膜的光催化性能.结果发现,掺杂适量的Ag有助于TiO2薄膜光催化氧化性能的提高,原因在于:（1）Ag通过引入耗尽层提高了TiO2的电荷分离能力,并吸引空穴向薄膜表面移动,结果使薄膜表面空穴的浓度提高,薄膜光催化效率提高;（2）Ag减小了TiO2粒子的粒径,使TiO2禁带宽度增大,薄膜光催化氧化的能力提高;（3）Ag掺杂后,TiO2薄膜表面对-OH基和水的吸附增加,使光照后TiO2薄膜表面活性自由基·OH的浓度增加,空穴向薄膜所吸附物质的转移能力提高.