A Novel Multi-Tube Photoreactor with UV Light and Immobilized TiO_2 Thin Film for Water Treatment

A novel multi-tube photoreactor with 0.0188m3 valid reaction volume was constructed in pilot-scale. This rectangular reactor consisted of 13 regularly distributed silica glass tubes coating with TiO2 thin film photo-catalyst. Total active area of TiO2 thin film is 0.3916m2. The ratio of surface area to volume achieves 20.8m-1. Photocatalytic experiment of phenol red demonstrates that the apparent reaction rate constant (k) is 0.074 65 h-1 and 0.16502h-1 for reaction system with and without micro-bubbles mixing. The corresponding apparent quantum efficiency (a) is 8.1771 X 10-7g.J-1 and 4.9036 x 10-7g-J-1, respectively. COD value of reactant could decrease to 17mg.L-1 and high performance liquid chromatography (HPLC) only shows two absorption peaks in 24 h pho-tocatalytic process time, so this photoreactor has good photomineralization effect. Experimental results reveal that photocatalytic destruction of organics is possible by using the multi-tube photoreactor.

Properties of TiO_2 Thin Films Prepared by Magnetron Sputtering

With rapid progressive application of TiO2 thin films, magnetron sputtering becomes a very interesting method to prepare such multi-functional thin films. This paper focuses on influences of various deposition processes and deposition rate on the structures and properties of TiO2 thin films. Anatase, rutile or amorphous TiO2 films with various crystalline structures and different photocatalytic, optical and electrical properties can be produced by varying sputtering gases, substrate temperature, annealing process, deposition rate and the characteristics of magnetron sputtering. This may in turn affect the functions of TiO2 films in many applications. Furthermore, TiO2-based composites films can overcome many limitations and improve the properties of TiO2 films.

OPTICAL CHARACTERIZATION OF TiO_2 THIN FILM ON SILICON SUBSTRATE DEPOSITED BY DC REACTIVE MAGNETRON SPUTTERING

TiO2 thin film has attracted considerable attention in recent years, due to its different refractive index and transparency with amorphous and different crysta ls in the visible and near-infrared wavelength region, high dielectric constant, wide band gap, high wear resistance and stability, etc, for which make it being used in many fields. This paper aims to investigate the optical characterizatio n of thin film TiO2 on silicon wafer. The TiO2 thin films were prepared by DC re active magnetron sputtering process from Ti target. The reflectivity of the film s was measured by UV-3101PC, and the index of refraction (n) and extinction coef ficient (k) were measured by n & k Analyzer 1200.

Preparation and Properties of Ag-TiO_2 Thin Films on Glass Substrates

Ag TiO 2 thin films were prepared on glasses.The morphology and structure of Ag TiO 2 films were investigated by XRD, SEM and FT IR.The photocatalytic and hydrophilic properties of Ag TiO 2 thin films were also evaluated by examining photocatalytic degradation dichlorophos under sunlight illumination and the change of contact angle respectively.The research results show that the Ag TiO 2 thin film is mainly composed of 20-100nm Ag and TiO 2 particles.The Ag TiO 2 thin films possess a super hydrophilic ability and higher photocatalytic activity than that of pure TiO 2 thin film.

Effect of initial precursor concentration on TiO_2 thin film nanostructures prepared by PCVD system

TiO2 thin film was prepared on Si substrate by plasma chemical vapor deposition （PCVD） system and the morphologies of ZiO2 thin film were controlled by adjusting the initial precursor concentration. As the initial titanium tetra-isopropoxide （TTIP） concentration increases in PCVD reactor, the shapes of TiO2 particles generated in PCVD reactor change from the spherical small-sized particles around 20 nm and spherical large-sized particles around 60 nm to aggregate particles around 100 nm. The TiO2 particles with different shapes deposit on the substrate and become the main building blocks of resulting TiO2 thin film. We observed the TiO2 thin film with smooth morphology at low initial TTIP concentration, granular morphology at medium initial TTIP concentration, and columnar morphology at high initial TTIP concentration. It is proposed that we can prepare the TiO2 thin film with controlled morphologies in one-step process just by adjusting the initial precursor concentration in PCVD .

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.

PREPARATION AND SURFACE CHARACTERIZATION OF TiO_2 THIN FILMS ON GLASS BY MAGNETRON SPUTTERING METHOD

Ti thin films were firstly deposited on glass substrates by magnetron sputtering method, then sintered the Ti thin films in air atmosphere and finally TiO2 transparence thin films on glass substrates were obtained. The structure and surface morphologies of the thin films were characterized by X-ray diffraction and SEM. The growth process of the thin films has been observed. The annealing time and annealing temperatures have an affect on the growth of the films.

Sensitizing Mechanism and Adsorption Properties of Dye-sensitized TiO2 Thin Films

The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces, and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were investigated. The influence of the application conditions of dye adsorbed on TiO2 films on the amount of dye adsorption was discussed. Experimental results show that the concentration, the temperature of dye solutions and the dipping time of TiO2 films in the dye solutions have a significant influence on the amount of dye adsorption. Cell test indicates that the conversion efficiency of light to electricity increases with the amount of dye adsorption.

Nanostructure Study of TiO2 Films Prepared by Dip Coating Process

The microstructure properties of the sol-gel derived TiO2 films were studied by the atomic force microscopy (AFM). The films were prepared by dip coating process. The optical properties of the films were explained on the basis of the microstructure of the films.

Low Temperature Coating of Anatase Thin Films on Silica Glass Fibers by Liquid Phase Deposition

Uniform crystalline TiO2 thin films were coated on silica glass fibers by liquid phase deposition from aqueous solution of ammonium hexafluorotitanate at low temperature. TiO2 thin films and nanopowders were prepared by adding H3BO3 into （NH4）2TiF6 solution supersaturated with anatase nano-crystalline TiO2 at 40 ℃. The effects of the deposition conditions on the surface morphology, section morphology, thickness of the deposited TiO2 thin films were investigated. The results indicate that the growth rate and particle size of the thin films were controlled by both the deposition conditions and the amount of anatase nano-crystalline TiO2.

TiO_2薄膜光电协同催化氧化降解活性艳红

以不同波长紫外光为光源 ,研究了活性艳红在间歇式反应器中的光降解、光催化降解、光电协同催化降解行为 .结果表明 :在相同条件下 ,光催化降解速度快于光降解速度 ,而光电协同催化降解速度取决于协同电场的方向 ,当电场方向与紫外线照射方向相同时 ,降解速度比光催化速度慢 ,而当电场方向与紫外线照射方向相反时 ,其降解速度快于光催化降解速率 .

液相沉积法制备光催化活性TiO_2薄膜和纳米粉体

采用液相沉积法 ,在 3 5℃通过向六氟钛酸铵水溶液中添加硼酸和结晶诱导剂锐钛矿型TiO2 纳米晶 ,沉积出具有光催化活性的TiO2 薄膜和纳米粉体 .用XRD ,AFM ,阶梯仪 ,UV vis ,BET法对TiO2 薄膜和粉体的沉积条件、结构、厚度和性能进行了测定和表征 ,并用亚甲兰的降解 ,评价了TiO2 薄膜和纳米粉体的光催化活性 .结果表明 ,当反应物六氟钛酸铵与硼酸的摩尔比为 1∶2～ 1∶4时 ,沉积的粉体和薄膜含有锐钛矿相TiO2 ;经 3 0 0℃热处理的TiO2 薄膜和纳米粉体具有最高的光催化活性 ,它的光催化活性是未经热处理前的 5倍 .本文还解释了经 3 0

Fe_2O_3掺杂TiO_2薄膜对甲基紫溶液光催化降解

甲基紫是一种相当稳定的有机物 ,能被 Ti O2 光催化降解 .本文采用 sol-gel工艺在玻璃表面制得了均匀透明的 Ti O2 薄膜 ,研究了热处理温度、涂覆层数、掺杂 Fe2 O3 等制备工艺 ,以及溶液 p H值和助催化剂H2 O2 等因素对 Ti O2 薄膜的光催化性能和稳定性的影响 .结果表明 ,掺 Fe2 O3 的 Ti O2 薄膜对甲基紫的降解率明显优于未掺 Fe2 O3 的 Ti O2 薄膜 .

碳黑改性TiO_2薄膜光催化剂的结构性质

通过碳黑掺杂制备了改性的TiO2 薄膜光催化剂 (CB TiO2 ) ,并采用液氮吸附、X射线衍射 (XRD)和紫外 可见光漫反射光谱 (DRS)对催化剂的比表面积、物相、晶粒度和最大激发波长等结构性质进行了表征 .结果表明 ,CB TiO2 的吸附性能大大改善 ,不同热处理温度下 ,BET比表面积增加 5 0 %～ 80 % ;同时碳黑掺杂能够减小催化剂的晶粒尺度 ,使相变温度降低 .相应的光催化降解试验也表明 ,碳黑改性TiO2 的活性大大提高 ,其一级反应速率常数为普通TiO2 的 1

退火温度对纳米TiO_2薄膜结构和亲水性的影响

采用射频磁控溅射方法制备出纳米二氧化钛 (TiO2 )薄膜 ,研究了不同退火温度对薄膜微观结构和超亲水性的影响。结果表明 :退火温度升高 ,晶粒长大 ,孔隙率减小 ;常温制备 30 0℃以下退火的TiO2 薄膜为无定形结构 ,亲水性差 ;4 0 0℃～ 6 5 0℃退火的薄膜为锐钛矿结构 ,表现出超亲水性 ;80 0℃退火薄膜为金红石结构 。

TiO_2薄膜的结构和光学性质的研究

以金属钛为靶材 ,用反应射频溅射法制备了TiO2 薄膜 ,并在 6 0 0～ 90 0℃下进行了热处理 .经XRD测量 ,在 6 0 0～ 80 0℃下TiO2 薄膜为锐钛矿和金红石两种结构的混合态 ,在 90 0℃下TiO2 薄膜为纯金红石结构 .研究TiO2薄膜的SEM照片和UV vis透射光谱发现 ,不同的热处理温度会影响TiO2 薄膜中锐钛矿和金红石两种结构的比例 ,从而导致TiO2 薄膜的微观形貌、折射率、禁带宽度等性质的变化 .

碳黑改性TiO_2薄膜光催化剂的研制

通过掺杂碳黑来提高 Ti O2 薄膜光催化剂的吸附性能 ,消除固定膜反应体系中经常出现的传质限制问题 ,使催化剂的活性由未经改性的 3 .2 mg/L提高到 4.8mg/L ,相当于浓度为 0 .2 g/L Degussa P2 5 Ti O2 悬浮体系的效果。同时研究了影响催化剂活性的主要制备条件。获得的适宜制备条件为浓硝酸添加量 1.0 m L,热处理温度 5 0 0℃ ,热处理时间 2 h,最佳涂覆次数为 8次。

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 。

染料敏化TiO_2纳晶太阳能电池研究进展

介绍染料敏化纳米晶 Ti O2 太阳电池的结构及其原理 ,对影响其光电转换效率的关键因素如纳米 Ti O2 膜、敏化染料、电解质做了探讨 .同时 ,对有机太阳能电池进行讨论并提出今后的研究方向 .

纳米TiO_2/玻璃膜的制备及其光催化性能

以钛醇盐为原料 ,采用溶胶 凝胶法制备了纳米TiO2 /玻璃薄膜。XRD、AFM和厚度分析表明 ,纳米TiO2 /玻璃薄膜中TiO2 为锐钛矿型结构 ,粒径为纳米级 ,三层膜的总厚度为 2 0 0nm。通过调节热处理温度 ,能有效控制薄膜中粒子的大小。UV VIS吸收光谱表明 ,TiO2 /玻璃薄膜可以有效地降解罗丹明B染料废水 ,其光催化活性随TiO2 粒径的减小而增大 ,受膜厚增加的影响不大。