复合电沉积制备SnO2/TiO2薄膜及其光电催化性能

为了寻求廉价、高效和稳定的光催化剂,用复合电沉积技术在紫铜片上制备了Sn/TiO2薄膜,经300℃热氧化使之形成SnO2/TiO2复合电极.利用SEM,XRD对薄膜进行了表征,以甲基橙为模型化合物,对复合电极的光催化和光电催化性能进行了测定.研究表明:该薄膜由0.3~1μm的颗粒构成,每个颗粒又由纳米晶粒形成;电极具有多孔结构,膜中的SnO2以两种不同的晶体结构存在;在薄膜质量相等的情况下,SnO2/TiO2薄膜的光催化活性是纯TiO2粒子膜的2.87倍;外加一定偏压下,其催化性能大幅度提高.     

Photocatalytic Property of TiO2 Films Deposited by Pulsed DC Magnetron Sputtering

TiO2 thin films were prepared by DC magnetron sputtering with the oxygen flow rate higher than the threshold. The film deposited for 5 h was of anatase phase with a preferred orientation along the <220> direction, but the films deposited for 2 and 3 h were amorphous. The transmittance and photocatalytic activity of the TiO2 films increased constantly with increasing film thickness. When the annealing temperature was lower than 700℃, only anatase grew in the TiO2 film. TiO2 phase changed from anatase to rutile when the annealing temperature was above 800℃. The photocatalytic activity decreased with increasing annealing temperature.     

负载型纳米二氧化钛光催化剂制备及其光催化性能研究

以粉煤灰分离出来的微珠为载体,采用不同方法制备TiO2负载膜光催化剂,通过XRD、SEM技术对粉煤灰微珠负载TiO2光催化剂的晶型结构和形貌进行了表征,以偶氮染料甲基橙为降解对象,考察不同负载方法、负载层数以及负载量对TiO2光催化活性的影响.结果表明:改良溶胶-凝胶法负载的TiO2薄膜催化剂的催化活性最高,同时负载的薄膜催化剂的催化活性明显高于TiO2 粉末催化剂.     

Effects of mineral tourmaline particles on the photocatalytic activity of TiO2 thin films

Titania composite thin films (T/TiO2) containing tourmaline particles were prepared by a sol-gel method, using alkoxide solutions as precursor. The tourmaline particles and thin films were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and so on. The effects of tourmaline on the photocatalytic activity of TiO2 were measured with methyl orange as an objective photodegradation substance. The results showed that the photocatalytic degradation of methyl orange conformed to the first-order kinetic equation and the composite thin films had better photocatalytic activity due to the cooperation of polarity and the far infrared emission of tourmaline. The T/TiO2 thin films including 0.5 wt% tourmaline exhibited better photocatalytic activity when heat-treated at 250 degrees C for 3 h, than pure TiO2 thin films under the ultraviolet irradiation.     

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。     

玻璃基TiO_2-Fe_2O_3-CeO_2复合纳米薄膜的光催化性能研究

在溶胶-凝胶法制备的TiO2胶膜表面涂覆金属离子,通过焙烧制备TiO2-Fe2O3-CeO2复合纳米薄膜。以甲基橙为目标降解物,讨论过渡金属离子Fe3+和稀土金属离子Ce3+的掺杂对TiO2薄膜光催化活性的影响。采用SEM、XRD、EDS等表征手段对复合氧化物薄膜进行表征。结果表明:所制备的薄膜具有纳米结构;Fe3+、Ce3+单掺和Fe3+/Ce3+共掺均可提高TiO2薄膜的光催化性能,但相同条件下共掺离子的光催化活性更高。     

热处理工艺对多孔TiO2薄膜光催化性能的影响

以十八胺为模板剂,采用溶胶-凝胶法在玻璃基体上制备了多孔TiO2薄膜,研究了热处理工艺对薄膜理化性质及光催化性能的影响。随煅烧温度和煅烧时间的增加,TiO2薄膜表面逐渐形成清晰的孔结构,晶粒尺寸增大。薄膜由锐钛矿型TiO2组成,Ti以Ti 4+的形式存在。制备的TiO2薄膜厚度在200nm左右,薄膜的UV-Vis透射率随煅烧温度的升高呈下降趋势,随煅烧时间的延长先下降而后又上升。多孔TiO2薄膜光催化降解甲基橙结果表明,随煅烧温度升高薄膜的光催化活性增加,在500℃煅烧2h制备的薄膜具有最佳的光催化活性。     

Surface structure of the TiO2 thin film photocatalyst

Control of the surface structure of titanium dioxide thin film photocatalysts was successfully carried out by a polymer-doped dip-coating process. The thin films prepared were either transparent or opaque, depending on the molecular weight of the polymer doped. All the thin film photocatalysts had anatase form with similar crystallinity. The surface of the transparent thin films looked plain consisting of uniformly aggregated nanometer-size TiO2 particles, while the opaque thin films were formed of cubic crystalline TiO2 at the micrometer level. Both the transparent and opaque films showed catalytic activity for the elimination of NOx in air. The specific surface area and photocatalytic activity of the transparent thin film was almost the same as that of the opaque one. The activity of the thin films was almost equal to the commercial photocatalyst P25. Decrease in the film thickness led to a decrease of the elimination of NO in air by the thin films. The thin films were porous and the surface area was dependent on the film thickness. Adsorbed NO was photooxidized to NO2 by the thin films, while the NO2 formed was re-photooxidized to HNO3 before the desorption of NO2 from the film surface.     

纳米TiO2／Al2O3复合薄膜光催化特性研究

以电化学方法合成的Al2O3多孔膜为基体，采用交流电沉积的方法在膜孔中沉积纳米TiO2，制备出纳米TiO2／Al2O3复合薄膜。对TiO2／Al2O3复合薄膜的形貌、结构和组成进行了表征；对TiO2／Al2O3复合薄膜光催化甲基橙溶液进行了研究。结果表明Al2O3／TiO2复合薄膜呈现出较好的光催化活性，电沉积TiO2的时间、热处理温度、选择不同光源照射均对TiO2／Al2O3复合薄膜光催化活性有一定的影响。     

TiO_2-Al_2O_3负载型催化剂的制备及其光催化性能

以钛酸四丁酯和氢氧化钠为反应物,采用两步水热法制备TiO2纳米线,并将其原位负载于Al2O3载体上,研究它们对甲基橙的光催化降解性能。结果表明,锐钛矿相TiO2主要呈纳米线和八面体状负载在Al2O3载体上,当TiO2负载质量分数为30%,焙烧温度为400℃,催化剂用量为1.332 0 g/L时,TiO2-Al2O3负载型催化剂光催化降解甲基橙的性能最佳,光照5 h后,甲基橙在紫外和太阳光下的降解率分别达到58.9%和55.6%。相同实验条件下,TiO2-Al2O3负载型催化剂对甲基橙的降解率比单纯TiO2提高了35.1%。     

Pt-TiO2 thin films on glass substrates as efficient photocatalysts

Photocatalytic Pt-TiO₂ thin films of various thicknesses (ca. 20 to 100 nm) were prepared on Vycor glass substrates by spray-coating. The photocatalytic activity of the films was examined through the dehydrogenation of methanol in aqueous solution. The plot of the activity against the thickness of the film gave a sigmoidal curve. A drastic increase in activity was observed at about 50 nm thickness. From thin-film X-ray diffraction measurements of the films it was revealed that anatase was formed at a thickness of more than 50 nm, whereas amorphous TiO₂ was formed at thicknesses of less than 50 nm. The increase of activity was, therefore, attributed to the formation of anatase. Compared with powder catalysts, the thin films showed a remarkable improvement in specific photocatalytic activity due to the high dispersion of the catalyst.     

磁控溅射制备掺银TiO2薄膜的光催化特性研究

利用交流磁控溅射设备采用金属Ti靶在石英和硅衬底制备掺银TiO2薄膜,并利用SEM,XRD及吸收光谱等方法分析测试TiO2薄膜的性质,探讨了掺银对TiO2薄膜吸收光谱的影响.并通过对甲基橙溶液浓度变化研究了掺银TiO2薄膜光催化特性,分析了掺银对TiO2薄膜增强光催化作用的工作机理,研究结果表明掺银有利于TiO2薄膜对有机物的降解作用.     

热处理温度对TiO2/SiO2复合气凝胶光催化性能的影响

采用溶胶–凝胶法在常压下经不同温度热处理制备了TiO2/SiO2复合气凝胶光催化剂,利用XRD、TGA和BET等手段对其微观结构进行表征,以甲基橙溶液光催化降解实验评价其光催化性能,研究了热处理温度对TiO2/SiO2复合气凝胶的微观结构及光催化性能影响规律.结果表明:随着热处理温度升高,TiO2/SiO2复合气凝胶中锐钛矿结晶度升高,晶粒尺寸增大,比表面积减小,使TiO2/SiO2复合气凝胶对甲基橙溶液的光催化降解活性呈现先升后降的变化趋势.当热处理温度为700℃左右,紫外光照20 min TiO2/SiO2复合气凝胶对甲基橙溶液的降解率达到95.4%.     

掺铁二氧化钛薄膜的自组装制备和光催化性能研究

以TiCl4为钛源,SAMs为模板,Fe（NO3）3·9H2O为铁源,采用自组装方法于低温液相反应体系中分别成功地制备出大面积二维结构纳米的纯净和掺铁Ⅱ0：薄膜,通过拉曼光谱、高分辨透射电镜、荧光发射光谱等方法对样品进行表征,研究紫外光和可见光下纳米薄膜对甲基橙溶液的光催化降解过程以及紫外光下对甲苯的降解效率,探讨了掺铁后对TiO2：的光催化活性的影响,结果表明,此方法不需要高温煅烧即可得到高催化活性的以金红石为主的掺铁二氧化钛纳米薄膜。     

HNO3处理对TiO2纳米薄膜的光催化活性和表面微结构的影响

通过sol-gel工艺分别在钠钙玻璃和预涂SiO2涂层的钠钙玻璃基体上制备了TiO2光催化纳米薄膜．然后用1mol／L HNO3水溶液对煅烧后的薄膜进行酸处理。用X射线光电子能谱(XPS)、扫描电镜(SEM)和紫外可见光谱(UV—VIS)对酸处理前后TiO2纳米薄膜进行了表征。用甲基橙水溶液的光催化脱色来评价TiO2薄膜的光催化活性。结果表明：SiO2涂层能有效阻止钠离子从玻璃基体向TiO2薄膜的扩散，普通玻璃表面的TiO2纳米薄膜经HNO3处理后，薄膜的光催化活性明显增强。这是由于TiO2纳米薄膜中的钠离子浓度降低以及表面羟基含量增加的缘故。     

磁性纳米TiO2/SiO2/Fe3O4光催化剂的制备及表征

以纳米Fe3O4磁粉为核心，采用溶胶一凝胶法制备了TiO2／SiO2／Fe3O4复合光催化剂．用XRD、TEM及元素分析对其结构和表面形貌进行了表征．以具有偶氮染料结构的甲基橙水溶液为目标反应物，评价其光催化活性．结果表明，所制TiO2／SiO2／FeaO4样品为双层包覆型结构，SiO2为中间层，最外层是锐钛矿型的TiO2,该复合光催化剂对甲基橙溶液有较高的光催化活性，并具有可利用其磁性回收重用的特点，应用前景广泛。     

Photocatalytic degradation of methyl orange using a TiO2/Ti mesh electrode with 3D nanotube arrays

To further improve the photocatalytic techniques for water purification and wastewater treatment, we successfully prepared a new type of TiO(2)/Ti mesh photoelectrode, by anodization in ethylene glycol solution. The three-dimensional arrays of nanotubes formed on Ti mesh show a significant improvement in photocatalytic activity, compared to the nanotube arrays formed on foil. This can be demonstrated by about 22 and 38% enhancement in the degradation efficiency per mass and per area, respectively, when TiO(2)/Ti mesh electrode was used to photocatalyze methyl orange (MO). Furthermore, the effects of different parameters on MO photodegradation were investigated, such as different photoelectrode calcination temperature, the initial pH value of MO solution, and the present of hydrogen peroxide. The superior photocatalytic activity could be achieved by the TiO(2)/Ti mesh photoelectrode calcinated at 550 °C, due to the appearance of mixed crystal phases of anatase and rutile. In strong acidic or caustic conditions, such as pH 1 or 13, a high degradation efficiency can be both obtained. The presence of H(2)O(2) in photocatalytic reactions can promote photocatalytic degradation efficiencies. Moreover, the experimental results demonstrated the excellent stability and reliability of the TiO(2)/Ti mesh electrode.     

FeS2/TiO2复合薄膜光电性能

采用溶液浸渍法在ITO导电玻璃表面的多孔TiO2薄膜上沉积了FeS2薄膜.使用Fe2O3粉末保护裸露在外的ITO导电膜在硫气氛中热处理后,制得了FeS2/TiO2复合薄膜.应用B531/H数显测厚指示表、数字式四探针测试仪、XJCM-8太阳电池测试仪等研究了FeS2/TiO2复合薄膜的厚度、ITO导电玻璃的电阻率以及FeS2/TiO2复合薄膜的光电性能.结果表明：此方法制得的FeS2/TiO2复合薄膜具有良好的光电性能;且ITO导电膜的电阻率变化较小.因而适宜制备色素增感太阳能电池（DSSC）.     

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.     

溶胶凝胶法制备的TiO2薄膜结构对光催化活性的影响

TiO2多孔纳米薄膜采用溶胶－凝胶法在普通载玻片上制得。薄膜的结构如孔径、孔分布和厚度可控制。通过稀醋酸的分解来测定锐钛矿TiO2多孔薄膜的结构对光催化活性的影响。