固定在氧扩散膜表面的TiO2光催化膜

本文提出用氧扩散膜作ＴｉＯ２光催化膜的载体。介绍了氧扩散膜的制备及ＴｉＯ２在氧扩散膜表面的固定方法,ＴｉＯ２光催化膜的表面形态与微结构,不同条件下光催化分解草 的速度。     

TiO2纳米管阵列膜光催化降解苯胺

利用TiO2纳米管阵列光催化降解含苯胺水样,考察了影响苯胺降解率的各种因素。结果表明,在照射光源波长254 nm,反应时间120 min和苯胺水溶液pH=9时,TiO2纳米管阵列光催化氧化苯胺的效果最好,苯胺降解率达到87%;另外在苯胺水样中加入含Fe3+、Cu2+的金属盐和少量的H2O2氧化剂后,对TiO2纳米管阵列的催化活性具有促进作用,其苯胺降解率分别提高了42%、31%和19%。探讨了TiO2纳米管阵列光催化降解苯胺的反应机理。     

稀土掺杂TiO2光催化还原CO2

采用溶胶-凝胶法制备了稀土掺杂TiO₂纳米光催化剂,并应用于光催化还原CO₂/H₂O体系中。通过XRD对光催化性能进行表征,研究稀土离子掺杂和焙烧温度对光催化性能的影响。结果表明,稀土La和Ce的加入可以抑制TiO2的晶相转变,提高光催化性能。催化剂800 ℃焙烧可达到最好的光催化活性,在反应时间7 h、CO₂流量200 mL·min^-1和反应液中NaOH与Na₂SO₃浓度均为0.10 mol·L^-1条件下,甲醇产率高达315.49 μmol·g^-1。并对稀土掺杂TiO₂催化剂光催化还原CO₂的机理进行了探究。     

MoS2/TiO2光催化降解甲基红

利用硫化钠与钼酸钠为原料,通过盐酸酸化,在TiO2上沉积MoS2纳米片。利用甲基红为降解对象,研究合成的片状纳米MoS2/TiO2复合物的光催化性能。结果显示该复合物具有优良的光催化降解甲基红的性能;催化剂用量、甲基红初始浓度与初始pH等条件对甲基红降解存在明显影响。该催化剂在重复使用3次时,甲基红2 h的脱色率接近65%,表明催化剂具有较好的重复使用性能。     

富含氧空位纳米TiO2的合成及其光催化制备H2O2

本文以纳米TiO2（P25）为原料,通过简单的固相化学还原法制备了含有适宜含量氧空位（OV）的光催化剂TiO2-OV。对TiO2-OV的结构形貌、元素组成、OV含量和能带结构分别进行了XRD、SEM、XPS、EPR和UV-Vis DRS光谱测试,结合光催化实验、光电化学测量,考察不同NaBH4用量（当P25用量为2.0 g时的质量,下同）制备的TiO2-OV光催化生产H2O2的能力,并根据活性物种捕获实验推测光催化反应机理。结果表明,TiO2-OV是锐钛矿和金红石相混合物组成的高结晶;当NaBH4用量为10 mg时,所制备的材料TiO2-OV-10的直接带隙能（Eg）为2.77 eV,导带（CB）为-0.84 eV,此时展示出最佳的光催化生产H2O2性能,在模拟太阳光照射下,H2O2的生产效率为1752.8 μmol/(g·h)。经NaBH4热处理还原后之所以能表现出高效的光催化制备H2O2效率是因为TiO2表面产生了OV,适宜浓度的氧空位可作为电子陷阱,从而提高了光生电子-空穴的分离效率。经4次回收循环使用后,催化性能略有下降;TiO2-OV光催化生产H2O2的活性物种为超氧自由基（?O2-）、羟基自由基（?OH）和空穴（h+）。另外,CH3OH在促进光载体分离以及生成H2O2反应方面发挥了重要作用。本文为半导体光催化剂的设计策略提供了参考,并为了解光催化生产H2O2的机理提供了新视角。     

TiO2/FACs与TiO2/Mullite复合材料的制备及其光催化性能

分别以粉煤灰漂珠(简记为FACs)与海胆状莫来石球(简记为Mullite)为基体,采用溶胶浸渍工艺制备了TiO₂/FACs与TiO₂/Mullite型复合材料。通过X射线衍射(XRD)、扫描电子显微镜(SEM)以及电子能谱(EDS)对制备的材料进行了表征。研究了TiO₂/FACs与TiO₂/Mullite型复合材料在紫外光照射下对罗丹明B(RhB)的光催化性能。结果表明：经500℃煅烧后形成的锐钛矿型TiO₂均成功负载到粉煤灰漂珠与莫来石晶体上,在粉煤灰漂珠表面覆盖了一层厚薄不均的纳米级别的TiO₂薄膜,而在莫来石晶体上则出现了大量细小的TiO₂颗粒;在降解染料时间为180 min,TiO₂/FACs与TiO₂/Mullite复合材料对罗丹明B染料的降解率分别为84.8%和96.4%,降解速率为0.01088min^-1和0.02885 min^-1。     

TiO2光催化降解亚硝酸钠的研究

采用溶胶-凝胶法制备了TiO2光催化剂,以紫外光照射下的光催化降解亚硝酸钠为模型反应,以盐酸萘乙二胺显色法测定样品的吸光度,进而得出亚硝酸钠的转化率,并采用BET、XRD和IR对催化剂进行了表征。结果表明,500℃焙烧的TiO2催化剂比表面积为42.5 m2/g,平均孔径为5.8 nm,热稳定性好。400℃焙烧2 h的TiO2尚存在一定量的无定形相TiO2,500℃焙烧的TiO2完全转变为锐钛矿型TiO2,700℃时完全转化为金红石相。本实验最佳的反应条件为:TiO2(500℃,2 h)催化剂0.2 g,100 mL 0.125μg/mL亚硝酸钠溶液中,紫外光降解150 min,亚硝酸钠的降解率为100%;添加适量浓度的H2O2溶液,可促进亚硝酸钠溶液的转化。     

SiW12/聚苯胺/TiO2复合材料的光催化性能

以SiW12/PANI/TiO2为光催化剂。在紫外灯辐射下,研究了模拟染料废水甲基紫溶液的光催化降解的反应,考察了催化剂投加量、染料浓度、溶液的pH值对甲基紫降解率的影响。结果表明,甲基紫溶液光催化降解的最佳条件为:pH=5,SiW12/PANI/TiO2催化剂投加量为0.0125 g,浓度为5 mg/L,经30 W紫外灯照射90 min后,其降解率为90.69%。     

TiO2光催化氧化技术在水处理中的研究进展

TiO2光催化氧化技术具有工艺简单、能耗低、效率高、易操作、无二次污染等特点,被认为是降解持久性有机污染物最有前途、最有效的处理方法之一。本文综述了UV/TiO2光催化氧化技术在水处理中的应用研究进展。     

TiO2光催化降解有机染料的动力学研究

以灿烂绿和伊红-Y为研究对象,探讨了其在254 nm紫外光照条件下Ti O2光催化降解的影响因素以及光催化反应的动力学模型。研究结果表明,随着催化剂Ti O2投加量的增加以及反应时间的增长,两种染料的脱色率均随之升高。而增大两种染料溶液的起始浓度,两种染料的脱色率会随之下降。此外,p H值对于这两种染料的光催化降解影响十分明显。灿烂绿和伊红-Y的Ti O2光催化降解均符合准一级Langmuir-Hinshelwood方程。     

纳米TiO2多孔薄膜光催化剂制备的研究进展

TiO2多孔薄膜材料与体材料和厚膜材料相比，具有多孔结构和高比表面积，对外界的敏感程度大、响应快，吸附能力强、易于重复利用等优点，在光催化、催化剂载体、传感器及光电子器件等领域有着十分广泛的应用前景，因此，对纳米TiO2多孔薄膜制备及性能研究已成为材料相关领域的热点之一。本文综述了近年来制备纳米TiO2多孔薄膜的方法及影响因素，并讨论了目前存在的一些问题和今后的发展方向。     

新型Pyrex玻璃弹簧负载型TiO2催化剂构成的固定床光催化反应器

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TiO2, TiO2/Ag and TiO2/Au photocatalysts prepared by spray pyrolysis

TiO₂, TiO₂/Ag and TiO₂/Au photocatalysts exhibiting a hollow spherical morphology were prepared by spray pyrolysis of aqueous solutions of titanium citrate complex and titanium oxalate precursors in one-step. Effects of precursor concentration and spray pyrolysis temperature were investigated. By subsequent heat treatment, photocatalysts with phase compositions from 10 to 100% rutile and crystallite sizes from 12 to 120 nm were obtained. A correlation between precursor concentration and size of the hollow spherical agglomerates obtained during spray pyrolysis was established. The anatase to rutile transformation was enhanced with metal incorporations and increased precursor concentration. The photocatalytic activity was evaluated by oxidation of methylene blue under UV-irradiation. As-prepared TiO₂ particles with large amounts of amorphous phase and organic residuals showed similar photocatalytic activity as the commercial Degussa P25. The metal incorporated samples showed comparable photocatalytic activity to the pure TiO₂ photocatalysts.     

Fe_2O_3/FeVO_4新型光催化剂的制备及光催化性能

采用液相沉淀法制备新型FecO2/FeVO4光催化剂,研究不同Fe掺杂量和煅烧温度对Fe2O3/FeVO4光催化活性的影响.以甲基橙水溶液为光催化降解对象,考察掺杂后的样品在紫外和可见光作用下的光催化活性.结果表明:当Fe/V摩尔比为1.01:1,750℃煅烧4h制得的样品光催化活性最好,较纯FeVO4提高19%左右.实验确定了样品光催化甲基橙溶液的最佳投加量为4 g/L,100 min内对甲基橙溶液的脱色率达到82%.同时样品具有很好的重复利用性,循环使用5次后,样品的光催化效率仍能保持在80%左右.     

Photocatalytic activity of Cu2O/TiO2, Bi2O3/TiO2 and ZnMn2O4/TiO2 heterojunctions

Cu₂O/TiO₂, Bi₂O₃/TiO₂ and ZnMn₂O₄/TiO₂ heterojunctions were studied for potential applications in water decontamination technology and their capacity to induce an oxidation process under VIS light. UV–vis spectroscopy analysis showed that the junctions-based Cu₂O, Bi₂O₃ and ZnMn₂O₄ are able to absorb a large part of visible light (respectively, up to 650, 460 and 1000 nm). This fact was confirmed in the case of Cu₂O/TiO₂ and Bi₂O₃/TiO₂ by photocatalytic experiments performed under visible light. A part of the charge recombination that can take place when both semiconductors are excited was observed when a photocatalytic experiment was performed under UV–vis illumination. Orange II, 4-hydroxybenzoic and benzamide were used as pollutants in the experiment. Photoactivity of the junctions was found to be strongly dependent on the substrate. The different phenomena that were observed in each case are discussed.     

TiO2光催化剂的应用及其关键技术

通过论述TiO     

TiO2与TiO2—SiO2薄膜的表面性质及生物活性研究

采用溶胶－凝胶法在医用NiTi形状记忆合金表面制备了TiO2与TiO2-SiO2薄膜,用X射线（XRD）,红外光谱（FT－IR）,X射线光电子能谱（XPS）和原子力显微镜（AFM）对薄膜的表面组成,结构与形貌进行了研究,将表面涂有薄膜的试样浸入模拟体液（SBF）,用XPS分析Ca,P在薄膜表面的沉积情况,结果表明：TiO2-SiO2人有比TiO2膜更高的生物活性,主要原因是TiO2-SiO2薄膜表面存在较多的羟基基团,在模拟体液中诱导磷灰石沉积的能力较高,此外,薄膜的表面形貌对其生物活性也有一定的影响。     

Combined TiO2/SiO2 mesoporous photocatalysts with location and phase controllable TiO2 nanoparticles

Combined TiO₂/SiO₂ mesoporous materials were prepared by deposition of TiO₂ nanoparticles synthesised via the acid-catalysed sol–gel method. In the first synthesis step a titania solution is prepared, by dissolving titaniumtetraisopropoxide in nitric acid. The influences of the initial titaniumtetraisopropoxide concentration and the temperature of dissolving on the final structural properties were investigated. In the second step of the synthesis, the titania nanoparticles were deposited on a silica support. Here, the influence of the temperature during deposition was studied. The depositions were carried out on two different mesoporous silica supports, SBA-15 and MCF, leading to substantial differences in the catalytic and structural properties. The samples were analysed with N₂-sorption, X-ray diffraction (XRD), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) to obtain structural information, determining the amount of titania, the crystal phase and the location of the titania particles on the mesoporous material (inside or outside the mesoporous channels). The structural differences of the support strongly determine the location of the nanoparticles and the subsequent photocatalytic activity towards the degradation of rhodamine 6G in aqueous solution under UV irradiation.