Preparation of Nanometer-structured TiO_2 Thin Films by Sol-Gel Method

The transparent anatase TiO 2 nanometer thin films were prepared by the sol-gel method on soda-lime glass.X-ray diffraction,thermal analysis and UV-visible spectrophotometer were used to analyze the formation of the phases.Only increasing the heat-treatment time,the average grain size has no obvious change.The mechanism of grain growth in TiO 2 thin film is probably as follows:the grain of coating will become grain core later;TiO 2 sol constantly deposited on the surface of TiO 2 grain and formed membrane with increasing of coating cycle times;TiO 2 grain in the film grow steadily.

Surface Microstructure Characterization of Sol-gel Derived Porous TiO_2 Thin Films

Porous TiO2 thin films were prepared from alkoxide solutions with and without polyethylene glycol (PEG) by sol-get route on soda lime glass, and were characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that TiO2 film prepared from precursor solution without PEG is composed of spherical particles of about 100 nm and several nanometer mesoporous pores. With the increase of the amount of PEG added to the precursor solution, the diameter and the depth of the pores in the resultant films increas on the decomposition of PEG during heat-treatment, which lead to them increase of the surface roughness of the films. XRD and TEM results show that the single anatase phase is precipitated and there are some orientation effects in (101) direction.

Time-resolved Microwave Conductivity Studies on the Chemical Treatment of the Nanocrystalline Porous TiO2 Films

Effect of Ti(iso-C3H7O)4 treatment on the photoinduced charge carrier kinetics of nanocrystalline porous TiO2 films is studied by time-resolved microwave conductivity measurements. Analysis of the transient photoconductivity decays indicates that Ti(iso-C3H7O)4 treatment leads to an increased concentration of photogenerated charge carriers and a fast interfacial transfer rate of holes via the surface modification of the freshly growing TiO2 nanocrystallites.

Synthesis and Characterization of TiO₂Porous Films for Heterogeneous Photocatalysis

Heterogeneous photocatalysis is one of the advanced oxidation processes (AOP’s). These are very used nowadays for their implementation in tertiary water treatment with solar activation, with very good results. In this study, TiO2 porous films were synthesized by sol-gel method. Polyethylene glycol (PEG) 4000 was used as a templating reagent, which is oxidized at a lower temperature than TiO2. This allows the formation of a “skeleton” of porous TiO2 with increased surface area, resulting in higher photocatalytic activity. The film characterization was made with help of FE-SEM microscope, XRD diffractometer and scotch tape test. Finally, the oxidation experiments were performed using methylene blue as a model pollutant and they revealed an increase in the photocatalytic activity of porous films in comparison with the non-porous films.

Preparation and Characterization of Nano-ZnFe_2O_4/TiO_2 Films

The nano-ZnFe2O4/TiO2 films possess the functions of desulfurization and degradation for organic pollutants. The sols of ZnFe2O4/TiO2 were prepared by sol-gel method and coated on glass and porous ceramic by vertical coating and dipping-lift processes, respectively, and the samples were obtained after drying and sintering. The composition, appearance, absorption spectrum of the films, and the influence of the film on porous ceramic performances were analyzed using SEM, AFM, UVVis spectrometer, and mercury porosimeter, respectively, to determine the operation parameters of the multifunction porous ceramic elements for gas-purification.

In-situ fabrication of dual porous titanium dioxide films as anode for carbon cathode based perovskite solar cell

We develop a dual porous （DP） TiO2 film for the electron transporting layer （ETL） in carbon cathode based perovskite solar cells （C-PSCs）. The DP TiO2 film was synthesized via a facile PS-templated method with the thickness being controlled by the spin-coating speed. It was found that there is an optimum DP TiO2 film thickness for achieving an effective ETL, a suitable perovskite]TiO2 interface, an efficient light harvester and thus a high performance C-PSC. In particular, such a DP TiO2 film can act as a scaffold for complete-filling of the pores with perovskite and for forming high-quality perovskite crystals that are seamlessly interfaced with Ti02 to enhance interracial charge injection. Leveraging the unique advantages of DP TiO2 ETL, together with a dense-packed and pinhole-free TiO2 compact layer, PCE of the C-PSCs has reached 9.81% with good stability.

Preparation and Photocatalytic Property of Porous TiO_2 Film with Net-like Framework

By the UV-curing method, a porous TiO2 film with net-like framework has been prepared. The characterization results of the porous TiO2 film by means of SEM, TEM, XRD, and N2 adsorption-desorption analysis show that the net-like framework of the porous TiO2 film is composed of TiO2 nanoparticles, forming three dimensional porous structure. The porous TiO2 film exhibits higher photocatalytic activity for the degradation of methylene blue（MB） dye compared with the conventional dense TiO2 film.

Preparation of TiO2 and SiC Films from Their Precursors Using Electrospraying

Titanium dioxide(TiO2) films were prepared by cone - jet mode electrospraying a titanium ethoxideprecursor solution onto a silicon substrate.The effects of spraying time,substrate temperature and aging on thesurface morphology of the films prepared were studied.Thin films obtained after spraying for 600 s were aged atroom temperature to form a porous TiO2 network with pores in the size range of 100 - 500 nm.Thicker filmswere prepared by spraying for 3 000 s,but these cracked on drying although it can be concluded that films pre-pared using a higher substrate temperature were denser.By this method,SiC coating was also prepared on anAl2O3 substrate using polysilane as a precursor.The result implies the potential of an industrial production ofdye sensitized solar cells by electrospraying technique.

界面电子转移对纳米TiO_2薄膜导电性的影响

研究纳米 Ti O2 薄膜的导电性与薄膜厚度和基底材料的关系 .结果表明 ,沉积在 Ti和Si基底上的 Ti O2 薄膜的电阻率随着膜厚的增加而非线性增大 ,分别经历了导体、半导体到绝缘体或半导体到绝缘体的电阻率范围的变化过程 ,Ti O2 薄膜导电层厚度也不相同 ,沉积在玻璃表面 Ti O2 薄膜为绝缘体 .这些现象是界面电子在界面的转移所致 。

醋酸处理对TiO_2纳米薄膜光催化性能的影响

用溶胶 -凝胶方法在普通玻璃基体上制备了均匀透明的TiO2 纳米薄膜 ,并经 5 0 0℃煅烧 2h ,煅烧后的TiO2 薄膜在2mol·L-1的CH3 COOH水溶液中处理 2 4h ,最后分别在 10 0和 5 0 0℃进行第二次热处理 .醋酸处理前后的薄膜分别用UV vis ,SEM ,XRD和XPS进行了表征 ,并用甲基橙水溶液的光催化降解评价TiO2 纳米薄膜的光催化性能 .结果发现 :用醋酸处理后的TiO2 纳米薄膜的光催化活性高于处理前薄膜的光催化活性 ;而且 ,酸处理后经 5 0 0℃热处理的TiO2 纳米薄膜的光催化活性明显高于经 10 0℃热处理的TiO2

溶胶—凝胶工艺制备的TiO_2纳米薄膜及其表面结构

采用溶胶—凝胶工艺在玻璃表面制备了均匀透明的锐钛矿型ＴｉＯ２ 纳米薄膜， 其颗粒大小在４０ ～８０ ｎｍ 。薄膜的Ｘ 射线衍射分析表明， 当薄膜的厚度小于０ ．４５ μｍ 时， 薄膜中未出现明显的锐钛矿的衍射峰。Ｘ 射线光电子能谱（ＸＰＳ） 和电子自旋共振谱（ＥＳＲ） 的实验结果表明： 薄膜中除含有Ｔｉ， Ｏ 元素外， 还有一定量的来自有机前驱物中未完全燃烧的碳和少量从玻璃表面扩散到薄膜中的Ｎａ 和Ｃａ 元素； Ｔｉ 元素除了以＋ ４ 价形式存在外， 还有一定量的Ｔｉ 以＋ ３ 和＋ ２ 价形式存在。ＴｉＯ２ 薄膜在５３０ ｎｍ附近的宽吸收带也证实了ＴｉＯ２ 薄膜中低价钛元素的存在。

TiO_2多孔纳米薄膜的溶胶—凝胶法制备和光催化特性研究

锐钛矿型ＴｉＯ２ 多孔纳米薄膜可以从含聚乙二醇的钛醇盐溶胶前驱体中通过溶胶—凝胶法制备。涂层的形貌，如孔的大小和孔的分布可以通过聚乙二醇的加入量来控制。当聚乙二醇的加入量为０～２．０ｇ 时，孔径大小在０～４００ｎｍ 范围内变化。可见光透过光谱分析表明：随着ＴｉＯ２ 薄膜中气孔孔径增大，光的散射增强，透过率减小，该ＴｉＯ２ 镀膜玻璃对于紫外线具有吸收作用。有机磷农药敌敌畏水溶液在紫外灯照射和ＴｉＯ２ 多孔纳米薄膜的共同作用下被完全降解为无机物。光催化降解实验表明：在ＴｉＯ２ 薄膜中引入气孔增强了光催化活性，孔的大小和薄膜厚度对光解率有显著的影响。当孔径大小为５０～２００ｎｍ ，镀膜次数为１０～１５ 次时。

陶瓷表面TiO_2薄膜的制备及光催化性能研究

采用化学溶胶-凝胶法制备TiO2溶胶,用浸渍-提拉方式在陶瓷表面制成锐钛矿相TiO2薄膜。用X射线衍射法(XRD)确定了晶型及晶粒的大小;用光电子能谱测定了其微观成分及其含量;考察了7种过渡金属离子掺杂后对甲基橙降解的光催化性能的影响及其变化规律,并对陶瓷和玻璃的光催化活性进行了比较。实验结果表明:掺杂Mn及Ni离子对于提高TiO2薄膜的光催化活性有明显的促进作用,降解30min后,降解率分别达到79.7%,80.8%。瓷片和玻璃的光催化活性要视掺杂的金属离子而定,不同的掺杂离子对瓷片和玻璃的光催化活性有不同的作用效果。

多孔结构TiO_2纳米膜的光催化活性及其动力学研究

考察了多孔结构TiO2 膜的光催化活性 ,并通过X射线衍射 (XRD)、电镜分析 (SEM)、光电能谱分析 (XPS)对催化剂表面进行了表征 ,结果表明 :TiO2 的晶型为锐钛矿型 ,粒子平均半径为 32 .94nm ;这种结构TiO2 纳米膜在对甲基橙的降解中显示了较好的光催化活性 ( 5 0min光照后 ,最高降解率达到了 92 .1% ) ;对光催化动力学进行了初步研究 ,结果表明 。

纳米TiO_2/玻璃薄膜光催化降解亚甲基蓝的研究

用溶胶 -凝胶法在玻璃表面制备了均匀透明的纳米TiO2 薄膜 .采用高压汞灯为光源 ,敞口固定床反应器对水中染料亚甲基蓝进行了光催化氧化实验 .实验结果表明 :随着涂膜次数的增加 ,薄膜TiO2 负载量增加 ,锐钛矿晶相粒径增大 .TiO2 薄膜对亚甲基蓝氧化降解具有较高的光催化活性 ,降解反应符合一级速率方程 .

太阳光TiO_2多孔纳米薄膜光催化降解有机磷农药的研究

锐钛矿型 Ti O2 多孔纳米薄膜可以从含聚乙二醇的钛醇盐溶胶前驱体中通过浸渍提拉法制备 ;涂层的形貌如孔的大小和孔的分布可以通过聚乙二醇的加入量来控制 ,当聚乙二醇的加入量为 0— 2 .0 g时 ,孔径大小在 0— 40 0 nm范围内变化。可见光透过光谱分析表明 :随着 Ti O2 薄膜中孔径增大 ,光的散射增强 ,透光率减小 ,该 Ti O2 镀膜玻璃对于紫外线具有吸收作用。有机磷农药水溶液的太阳光催化降解实验表明 :在 Ti O2 薄膜中引入气孔增强了光催化活性 ,孔的大小和薄膜厚度对光解率有显著的影响。当孔径大小为 1 0 0— 2 0 0 nm,镀膜次数为 1 0— 1 5次时 ,Ti O2 薄膜显示光催化效率高。

涂层层数和保温时间对纳米TiO_2薄膜显微结构的影响

用溶胶凝胶法和高温煅烧在玻璃基体上制备纳米TiO2 薄膜 ,测试在各种工艺条件下制备的薄膜的亲水性、紫外线激发活性等性能 ,利用X射线衍射法和扫描电镜法表征其显微结构 ,并重点进行了涂层层数和保温时间对显微结构性能影响的研究。结果表明 ,涂层层数增加和保温时间延长不影响涂层中锐钛矿晶型的稳定性 ,对纳米TiO2 的颗粒长大也无明显影响。

Preparation and Characterization of Nanotitanium Dioxide Coating Film Doped with Fe^(3+) Ions on Porous Ceramic

The nanotitanium dioxide （TiO2） photocatalytic and porous ceramic filtering technique is one of the advanced methods to effectively treat organic wastewater. The TiO2 sol doped with Fe^3＋ ions was prepared by sol-gel processing. The influences of the process conditions of coating nanophotocatalytic material- Fe^3＋-TiO2 film on the surface of porous ceramic filter by dipping-lift method on the performance of porous ceramic filter were studied. The porous ceramic filters have two functions at the same time, filtration and photocatalytic degradation. The results of this study showed that the pH and viscosity of the sol, amount of Fe^3＋ ions doped as well as the coating times greatly affect the quality of coating film, the performance parameters and the photocatalytic activity of the porous ceramic filter. When the pH of the sol is 3-4, the viscosity is about 6 mPa.S, the amount of doped Fe^3＋ ions is about 2.0 g/L, the porous ceramic filter has been shown to have the best filtering performance and photocatalytic activity. In this condition, the porosity of porous ceramic is about 42.5%, the pore diameter is 8-10μm. The degradation of methyl-orange is 74.76% under lighting for 120 rain.

溶胶-凝胶工艺制备TiO_2薄膜的表面组成和价态研究

通过Ｘ射线光电子能谱（ＸＰＳ）和电子自旋共振谱（ＥＳＲ）， 确定了采用溶胶－凝胶工艺制备的ＴｉＯ２光催化纳米薄膜中元素的化学组成和价态． 实验结果表明， 薄膜中除含有钛和氧元素外，还有一定量的来自有机前驱物中未完全燃烧的残余碳和少量从玻璃表面扩散到薄膜中的钠和钙离子； Ｔｉ除了以Ｔｉ４＋ 价形式存在外， 还有一定量的Ｔｉ以Ｔｉ３＋ 和Ｔｉ２＋ 形式存在． 这种情况主要是由于有机基团的燃烧、来自玻璃基体中钠与钙离子的扩散和热处理工艺等原因造成的． ＴｉＯ２薄膜在５３０ ｎｍ 附近的宽吸收带， 也证实了ＴｉＯ２薄膜中低价钛元素的存在．