PBST/TiO_(2)/MgO复合薄膜的制备及性能

采用硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)对TiO_(2)/MgO NPs改性,采用溶液共混法制备了聚丁二酸-共-对苯二甲酸丁二醇酯(PBST)/TiO_(2)/MgO NPs纳米复合薄膜,并探讨了其在食品包装方面的应用。研究了改性TiO_(2)/MgO NPs对PBST基体机械、阻隔、抗菌和保鲜性能的影响。结果表明:复合膜的抗拉强度和水蒸汽透过率分别为29.39MPa和2.43×10^(-11) g·m/(m^(2)·s·Pa),相较PBST基体抗拉强度提高了24.32%,水蒸汽透过率降低了32.37%,且对金黄色葡萄球菌(S.aures)和大肠杆菌(E.coli)抑菌效果显著,分别达到98.7%和97.2%,并对圣女果有良好的保鲜性能,当改性后的TiO_(2)/MgO NPs质量含量为5%时,复合薄膜的性能最佳。

Formation Mechanistism Study of TiO2 Film Comprising Nanotubes and Nanoparticles

A novel titanium dioxide （TiO2） film comprising both nanotubes and nanopaticles was fabricated by an anodization process of the modified titanium. The local electric field at the anodized surface was simulated and its influence on the morphology of the TiO2 film was discussed. The results show that the electric field strength is enhanced by the covering. The growth rate of TiO2 increases with the assist of the local electric field. However, TiO2 dissolution is hindered since the local electric field prevents [TiF6]6- from diffusing. It means that the balance condition for the formation of nanotubes is broken, and TiO2 nanoparticles are formed. Moreover, the crystal structure of the TiO2 film was confirmed using X-ray diffraction and Raman analysis. The anatase is a main phase for the proposed film.

STUDY ON PHOTOCATALYTIC MECHANISM OF SOL-GEL-DERIVED Pb-DOPED TiO_2 THIN FILMS

Pb-doped TiO2 photocatalytic thin films were prepared on a soda-lime glass substrate via sol-gel method using TiO2 sol solution containing lead and characterized by X-ray photoelectron spectroscopy (XPS). The results showed that besides oxides of Ti(IV) there is a certain amount of oxides of To(?) and Ti(?) and Pb exists in the forms of PbTiO3 and PbO. The photocatalytic activity of the Pb-doped TiO2 films was evaluated by the photocatalytic decolorization of aqueous methyl orange and photocatalytic mechanism mas also analyzed.

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.

Study on UV Shielding TiO_2 Thin Film Prepared by Sol-Gel Method

Titanium dioxide (TiO_2) thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated sols.The results show that there exists anatase and rutile structure of TiO_2 when heat treatment temperature is 450℃,and at 800℃,TiO_2 particle size is of below 100 nm and rutile structure is presented.In the range of 360 nm～400 nm the transmittance of TiO_2 sol increases with the increasing of the concentration of Ti(OC_4H_9)_4 in ethanol solution. The transmittance of TiO_2 films with various number of the layer is measured to be 0% below 320 nm,and the three-layer TiO_2 film is of the best UV resistance in the range of 320 nm～400 nm.

Electrically enhanced photodegradation of an azodye(Acid Orange II) using a Pt/TiO_2 film electrode irradiating with an UV lamp

A photoelectrochemical process in the degradation of an azodye (Acid Orange II) on a Pt/TiO 2 film electrode was investigated. By using the glass device and the voltage stabilized source of direct current, decolorization ratios higher than 78% were observed during a period of 5h. Comparing this value with the sum of the decolorization ratios obtained by a sole application of electrochemical(lower than 3%) and photochemical(about 23%) procedures, a significant synergic effect between both processes was observed. The effects of adscititious voltage and pH value on the decolorization ratios were obvious while the effect of the amount of aeration was minor.

A STUDY ON PHOTOELECTROCHEMICAL CHARACTERIZATION OF TiO_2 NANOCRYSTALLINE THIN FILMS

Abstract:Nanocrystalline TiO2 thin films have been prepared on a conducting glass surface by coating quantized TiO2 colloids. The photoelectrochemical properties of TiO2 thin films and their dependence on various factors have been Studied. To obtain maximum photocurrent optimization of film thickness,sintering temperature and the PH of the electrolyte are very important.

Photostability Study of Nanoporous TiO_2 Film Electrodes in Basic Solutions

The nanoporous TiO2 film electrodes have been prepared by a sol-gel deposition process. The photostability of the electrodes in basic solutions has been studied. The results show that the photostability of the electrodes decreases rapidly in strong basic solutions with or without methanol. The reaction of holes to O2-ad produces active O-ad atoms and the products O-ad atoms oxidize Ti3+ to Ti4+ on TiO2 film surface and subsurface. This results in the TiO2 film electrodes unstable in basic solutions both without methanol and with too low concentration.

Dye-sensitized solid-state solar cells fabricated by screen-printed TiO_2 thin film with addition of polystyrene balls

The screen-printed nanoporous TiO2 thin film was employed to fabricate dye-sensitized solid-state solar cells using CuI as hole-transport materials. The solar cell based on nanoporous TiO2 thin film with large pores formed by the addition of polystyrene balls with diameter of 200 nm to the TiO2 paste exhibits photovoltaic performance enhancement, which is attributed to the good contact of CuI with surface of dye-sensitized thin film due to easy penetration of CuI in the film with large pores.

高硅氧纤维负载纳米Dy/TiO_2薄膜的制备及性能

为提高纳米TiO_2的光催化降解性能和稳定性,先采用微波-溶胶法制备Dy/TiO_2溶胶,再以高硅氧玻璃纤维编织体为载体,经过浸渍-提拉法制备具有高催化性能的高硅氧纤维负载纳米Dy/TiO_2薄膜。采用XRD,SEM,PL,EDS,XPS等仪器对薄膜的物相、表面形貌结构、表面元素组成及薄膜的稳定性进行表征,并且研究预处理液和涂覆方式对高硅氧纤维薄膜的影响。另外以甲基橙为目标降解物,考察样品的光催化性能。结果表明:以高硅氧玻璃纤维编织体为载体制备的Dy/TiO_2薄膜稳定性很好;经5次涂覆后,Dy/TiO_2高硅氧纤维薄膜对甲基橙的降解率在30min后达到94%。

Preparation and characterization of ZrO_2/TiO_2 composite photocatalytic film by micro-arc oxidation

ZrO2/TiO2 composite photocatalytic film was produced on the pure titanium substrate using in-situ Zr（OH）4 colloidal particle by the micro-arc oxidation technique and characterized by scanning electron microscope （SEM）, energy dispersive X-ray （EDX）, X-ray diffraction （XRD） and ultraviolet-visible （UV-Vis） spectrophotometer. The composite film shows a lamellar and porous structure which consists of anatase, futile and ZrO2 phases. The optical absorption edge of film is shifted to longer wavelength when ZrO2 is introduced to TiO2. Furthermore, the photocatalytic reaction rate constants of degradation of rhodamine B solution with ZrO2/TiO2 composite film and pure TiO2 film under ultraviolet irradiation are measured as 0.0442 and 0.0186 h 1, respectively.

Study of Properties of Lead Selenide （PbSe） Thin Films Deposited on TiO2

The study of nano properties of PbSe （lead selenide） thin films deposited on TiO2 semi conductor film prepared by sol gel method was a new work destined to perfect the nano materials used in photovoltaic energy. The growth of the first group of the fihns （Set 1： P（9）） ＆ P（14）） was based on the decomposition of lead citrate and sodium selenosulphite in the presence of sodium citrate and sodium hydroxide with ammonia and triethalamine （TEA） acting as the complexing agents and P.H stabilizers; while in the second group （Set 2： Pc15~）, the reaction bath was made up of solutions of lead nitrate Pb（NO3）2, PVA （polyvinyl alcohol）, H20 （distilled water）, NH3 （ammonia）, sodium selenosulphite （Na2SeSO3） and Triethalamine [N（CH2CH2OH）], which was used as the complexing agent. The deposited materials were identified by X-ray diffraction. In addition, nano optical and morphological investigations were also performed. The sample P9 has the lowest absorbance of about 0.3 nm in the ultra-violet region. It was found that there was a reduction in the optical absorbance as the wavelength increases. The optical band gap shows a range of 1.26-2.00 eV with sample PcIs~ having the lowest direct band gap.

Photoelectrocatalytic reduction of CO_2 into formic acid using WO_(3-x)/TiO_2 film as novel photoanode

A novel WO3-x/TiO2 film as photoanode was synthesized for photoelectrocatalytic（PEC） reduction of CO2 into formic acid（HCOOH）. The films prepared by doctor blade method were characterized with X-ray diffractometer（XRD）, scanning electron microscope（SEM） and transmission electron microscope（TEM）. The existence of oxygen vacancies in the WO3-x was confirmed with an X-ray photoelectron spectroscopy（XPS）, and the accurate oxygen index was determined by a modified potentiometric titrimetry method. After 3h of photoelectrocatalytic reduction, the formic acid yield of the WO3-x/TiO2 film is 872 nmol/cm^2, which is 1.83 times that of the WO3/TiO2 film. The results of PEC performance demonstrate that the introduction of WO3-x nanoparticles can improve the charge transfer performance so as to enhance the performance of PEC reduction of CO2 into formic acid.

Effect of Zn and Ti mole ratio on microstructure and photocatalytic properties of magnetron sputtered TiO_2-ZnO heterogeneous composite film

Series of TiO 2-ZnO heterojunction composite films with different n（Zn）/n（Ti） ratios were prepared by UDP450 magnetron sputter ion plating equipment, and the mole ratio of Zn to Ti was controlled by adjusting the current values of sputtering target. The effects of n（Zn）/n（Ti） on the microstructures of TiO2-ZnO films were investigated by SEM, AFM, Raman and XPS, and their photocatalytic decomposition of methyl orange solutions was evaluated. The results show that an increase in n（Zn）/n（Ti） typically results in a decrease in the grain size of composite films firstly and then an increase of grain size, while an increase in n（Zn）/n（Ti） leads to an increase in film roughness firstly and then a decrease in film roughness. Both grain size and roughness of TiO2-ZnO films reach the maximum and minimum at n（Zn）/n（Ti） of 1/9.3, respectively. The n（Zn）/n（Ti） shows little effect on the valences of Zn and Ti elements, which mainly exist in the form of TiO2 and ZnO phases. The n（Zn）/n（Ti） has influence on the amount of anatase/rutile TiO2 heterojunction in the film. With increase of the n（Zn）/n（Ti）, the absorption intensity of the composite film increases and the absorption region extends to 450 nm, which is redshifted as much as 150 nm in comparison with the pure TiO2 films. However, the photocatalytic abilities of heterogeneous composite films do not depend on the n（Zn）/n（Ti） but rather on the microstructures of the TiO2-ZnO composite films. Degradation rate of the film reaches the maximum and the photocatalytic decomposition of pollutants works best when n（Zn）/n（Ti）=1：9.3.

纳米Dy/TiO_2粉体的制备及光催化性能研究

以钛酸正丁酯和硝酸镝为主要原料,主要采用了微波-溶胶胶法制备出了一系列稀土Dy掺杂的纳米TiO_2粉体(Dy/TiO_2)。并且以甲基橙溶液为目标降解物,系统地研究了煅烧温度、稀土Dy掺量、煅烧时间等因素对纳米Dy/TiO_2粉体光催化性能的具体影响。通过SEM、XRD、UV-vis-DRS等表征手段对样品进行了分析。结果表明:在550℃下将稀土Dy掺量为1.3%的纳米TiO_2粉体煅烧4 h,降解效率就达到90%以上。稀土掺杂后不仅仅使得纳米TiO_2颗粒尺寸减小,带隙减小,吸收波长红移约30 nm,还能有效的抑制光生电子-空穴的复合。

稀土Dy^(3+)掺杂TiO_2的制备及光催化性能研究

采用溶胶-凝胶法合成了不同Dy3+掺杂量、不同焙烧温度的Ti O2光催化剂.并对所制得的光催化剂进行了SEM、XRD和FT-IR的表征和光催化活性研究.结果表明:所得粉体均为锐钛矿相纳米Ti O2,稀土掺杂能细化晶粒.以酸性品红为降解物的光催化实验表明:500℃煅烧,当Dy3+掺杂量为0.20%时其光催化活性最好,加入1 m L 30%H2O2,无灯源照射,常温常压无须通氧气条件下,催化时间6 h,降解率达到81.19%.

Sr_4Al_(14)O_(25):Eu^(2+),Dy^(3+)/TiO_(2-x)N_x复合材料制备及光催化性能

采用溶胶-凝胶法在长余辉发光材料(Sr4Al14O25:Eu2+,Dy3+)的表面包覆TiO2-xNx。利用X-射线衍射(XRD)、扫描电子显微镜(SEM)对复合材料的结构,形貌进行了表征;并研究了Sr4Al14O25:Eu2+,Dy3+/TiO2-xNx复合材料对甲基橙的光催化降解性能。

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.

光照对Sr_4Al_(14)O_(25):Eu^(2+),Dy^(3+)/TiO_(2-x)N_x复合材料光催化性能的影响

采用溶胶-凝胶法制备出Sr4Al14O25:Eu2+,Dy3+/TiO2-xNx复合材料。该复合材料对甲基橙具有较高的光催化效果,复合材料经紫外激发后,其光催化效果高于没有经紫外激发的复合材料的光催化效果,而且明显高于Sr4Al14O25:Eu2+,Dy3+和TiO2-xNx光照激发后光催化效率之和,同时讨论了Sr4Al14O25:Eu2+,Dy3+/TiO2-xNx复合材料的光催化机理。