TiO2-Loaded WO3 Composite Films for Enhancement of Photocurrent Density

Titanium dioxide （TiO2） loaded tungsten trioxide （WO3） composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO2 and WO3, the prepared TiO2-WO3 composite film shows enhanced photocurrent density, four times than the pure WO3 film illuminated under xenon lamp, and higher incident-photon-to-current conversion e^ciency. By varying the initial TiO2 film thickness, such composite structures could be optimized to obtain the highest photocurrent density. We believe that thin TiO2 films improve the light response and increase the surface roughness of WO3 films. Furthermore, the existence of the heterojunction results in the e^cient charge carriers＇ separation, transfer process, and a lower recombination of electron-hole pairs, which is beneficial for the enhancement of photocurrent density.

Preparation and photocatalysis properties of composite photocatalyst CoPcS/TiO2/K2Ti4O9

Photocatalyst CoPcS/TiO2 was prepared by sol-gel method. Composite CoPcS/TiO2/K2Ti4O9 was prepared by dipping. It was incandesced at various temperatures and modification effect was compared. The results showed that optical absorption of sample incandesce at 423K occurred significant red-shift. Light absorption width extended from ultraviolet region to visible region, especially there was an intensive absorption between 600 nm and 680 nm. X-ray diffraction spectrogram showed that TiO2 in sample still maintained anatase crystal form. Under the illumination of visible light, photocatalysis degradation experiment was taken with Eosin B as simulated pollutants. Decoloration rate of Eosin B was much improved. The rate can reach 80% in 300 minutes.

Electrophoretic Deposition of TiO2/Nb2O5 Composite Electrode Thin Films for Photovoltaic Application

Nano sized powders of TiO2 （titanium dioxide） and Nb2O5 （Niobium （V） oxide） were used to fabricate TiO2/Nb2O5 composites thin films by EPD （electrophoretic deposition） technique. The metal oxide powders, together with magnesium nitrate hexahydrate pellets, were suspended in propan-2-ol inside an EPD cell. The electrodes, placed 1.2 cm apart, were partially immersed in the suspension and a DC potential applied across them. Key EPD process parameters, which include applied DC electric field, deposition time and solid concentration in suspension, were optimized through visual inspection and from UV-Vis-NIR spectrophotometer spectra. The highest （55%） transmittance was obtained for films with deposition time of 90 s, powder concentration of 0.01 g/40 mL, and 35 V DC （direct current） voltage. XRD micrographs confirmed that TiO2 and Nb2O5 particles were presented in the composite film. SEM （scanning electron microscope） micrographs of the composite electrode thin films showed that porous films of high quality with well controlled morphology were deposited by using the EPD technique.

PREPARATION AND CORROSION RESISTANCE OF NiP/TiO_2 COMPOSITE FILM ON CARBON STEEL IN SULFURIC ACID SOLUTION

A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM （environmental scanning electron microscopy） and EIS （electrochemical impedance spectroscopy） measurements. Results showed that the NiP/ TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS （X-ray photoelectron spectroscopy） spectrum, and an anticorrosion mechanism of the composite film was discussed.

Preparation and photocatalytic activity of PANI/TiO_2 composite film

A PANI/TiO2 composite film deposited on the glass surface was successfully prepared using sol-gel dip-coating technique and chemical oxidation method. The film was characterized using XRD, AFM, and UV. The result showed that the TiO2 film consists of both cuboid-shaped and anatase-phased TiO2 nanoparticles. The average grain size of TiO2 in the film was approximately 20 nm. After coating with PANI, the particle was changed into irregular spherical-shaped and the size was increased up to approximately 35 nm in diameter. UV-Vis spectroscopy analysis indicated that the coating of TiO2 with PANI would result in an enhancement of photocatalytic efficiency and an extension of the photoresponse of TiO2. The band gap of the PANI/TiO2 film was 3.18 eV. The photocatalytic property of the film was evaluated by the degradation of rhodamine-B. It was found that 67.1% and 83.2% of rhodamine-B could be degraded under sunlight and UV irradiation within 120 min using the PANI/TiO2 composite t-tim as photocatalyst.

Formation of TiO2 Modified Film on Carbon Steel

A new technique for preparing TiO2 modified film on carbon steel was accomplished by electroless plating and sol-gel composite process. The artificial neural network was applied to optimize the preparing condition of TiO2 modified film. The optimized condition for forming TiO2 modified film on carbon steel was that NiP plating for 50 min, dip-coating times as 4, heat treatment time for 2 h, and the molar ratio of complexing agent and Ti(OC4HZ9)4 kept 1.5:1. The results showed that TiO2 modified film have good corrosion resistance. The result conformed that it is feasible to design the preparing conditions of TiO2 modified film by artificial neural network.

Synthesis and Photocatalytic Property of ZnO/TiO2 Inverse Opals Films with Controllable Composition and Topology

A novel method to fabricate composition- （IO） films using a positive sacrificial ZnO and topology-controlled ZnO/TiO2 inverse opals IO template has been developed. This method includes a two-step process, preparation of ZnO IO by a simple electrochemical deposition using a self-assembly polystyrene colloidal crystal template and preparation of ZnO/TiO2 IO by a liquid phase deposition （LPD） process at room temperature. The composition and topology of ZnO/TiO2 IO can be easily controlled by changing the duration of the LPD. After 20 min LPD process, a ZnO/TiO2 composite IO with non-close-packed face-centered cubic air sphere array was obtained. Prolonging the duration to 60 min, a pure TiO2 IO （TIO-LPD60） with obviously thickened walls was formed. The formation mechanism for the compositional and topological variation was discussed. A preliminary study on UV photocatalytic property of the samples for degradation of methylene blue reveals that the composition and topology significantly influenced the photocatalytic activity of the IO film. The ZnO/TiO2 composite IO demonstrates a higher degree of activity than both pure ZnO and pure TiO2 IO, although they have a similar IO wall thickness. Moreover, with increasing IO wall thickness from -52 nm to -90 nm, TIO-LPD60 exhibits the highest level of photocatalytic performance.

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.

High photocatalytic activity of Cu2O/TiO2/Pt composite films prepared by magnetron sputtering

Cu2O/TiOa/Pt three-layer films were deposited on glass substrates using magnetron sputtering method. The surface morphology and the optical properties of the composite film were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, ultraviolet- visible spectroscopy （UV-Vis） and photoluminescence spectroscopy （PL）. The photocatalytic activity of the samples was evaluated by the photocatalytic degradation of methyl orange （MO） aqueous solution under visible light irradiation. The results indicate that the Cu2O/TiO2/Pt composite films are made up of three layers which are Pt layer, anatase-TiO2 layer and Cu2O layer from bottom to top. The surface of the films is even and composed of regular-shaped spherical particles. The photocatalytic activity of the Cu2O/TiO2/Pt three-layer film is much higher than that of the Cu2O/TiO2 double-layer film. Such enhancement is ascribed to the presence of Pt layer, which further inhibits the photogenerated electron-hole recombination, prolongs the lifetime of the photogenerated carriers, increases the quantum efficiency and hence improves the photocatalytic activity of the film effectively.

复合材料TiO2/MoS2的制备及对油田废水处理

以钛酸丁酯和钼酸铵为前驱体,采用溶胶-凝胶法和水热法分别制备TiO 2、MoS 2和TiO 2/MoS 2纳米材料,并通过FTIR、XRD、SEM、DRS和BET等手段表征其结构、组成、形貌和孔径大小。以油田废水为光催化降解反应模型,考察了光催化活性,测定了催化剂的容量、反应条件如投加量、pH值、反应时间等因素。处理废水为200 mL,TiO 2、TiO 2/MoS 2投加量为0.8 g,pH=3~4,反应时间为40 min对油田废水中油污的去除率分别为79.4%、92.7%;悬浮物的去除率分别为83.5%、94.3%。结果表明TiO 2/MoS 2对油田废水处理效果明显高于纯TiO 2。

Cd S/TiO2/ACFs光催化处理染料废水的试验研究

采用负载型CdS/TiO2/ACFs复合半导体材料对孔雀石绿染料废水进行光催化处理,分别考察了pH、反应时间、催化剂投加量等因素对处理效果的影响。结果表明:负载型CdS/TiO2/ACFs复合半导体对色度为250倍、COD为444mg/L的孔雀石绿染料废水,色度、COD去除率分别为97%和88%。

N-TiO2/g-C3N4复合光催化剂的制备及其光催化性能

采用水热法制备N掺杂TiO2,将其与二氰二胺混合进行高温焙烧合成N-TiO2/g-C3N4复合光催化剂。采用XRD、UV-Vis、N2吸附-脱附和SEM等对催化剂进行微观结构表征,以200W氙灯模拟光源并过滤掉420nm以下的紫外光,对比研究TiO2、g-C3N4、N-TiO2和复合光催化剂对罗丹明B的可见光降解性能。结果表明,N掺杂后TiO2的禁带宽度降低,催化活性提高;而复合光催化剂可见光吸收边距相对N-TiO2进一步红移,禁带宽度为2.75eV,降解罗丹明B的一级动力学常数k可达0.12158min-1,是g-C3N4、N-TiO2的2倍;复合催化剂重复使用4次后,对罗丹明B的降解率仍达92%以上,表明催化剂具有较好的光催化活性和稳定性。

TiO2-Ag复合薄膜的制备及其抗菌性能

采用水热处理-光化学沉积两步法在钛片表面构筑出TiO 2-Ag复合薄膜。借助扫描电镜(SEM)、X射线衍射(XRD)、拉曼光谱(Raman)、X射线光电子能谱(XPS)对薄膜的形貌、物相及化学组成进行表征。结果表明:钛片经历水热处理并煅烧后,在其表面获得了由厚度10~30 nm的纳米片自组装而成的锐钛矿型TiO 2多孔薄膜;将该薄膜置于AgNO 3水溶液中用紫外光照射10 min后,在其表面得到了分散均匀的以单质形态存在的Ag纳米颗粒;随紫外光照射时间的延长,Ag纳米颗粒的尺寸逐渐增大,并出现聚集生长的趋势。以大肠杆菌为实验菌种,采用覆膜-平板计数法对不同光沉积时间下得到的3种载Ag二氧化钛薄膜的抗菌性能进行了评价。结果表明:3种TiO 2-Ag复合薄膜对大肠杆菌均显示出良好的抗菌效果。

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.

Corrosion Resistance of Sintered NdFeB Permanent Magnet With Ni-P/TiO_2 Composite Film

The Ni-P/TiO2 composite film on sintered NdFeB permanent magnet was investigated by X-ray diffraction （XRD）,environmental scanning electron microscopy （ESEM）,and energy dispersive X-ray spectrometer （EDX）. The corrosion resistance of Ni-P/TiO2 film coated on NdFeB magnet,in 0.5 mol/L NaCl solution,was studied by potentiodynamic polarization,salt spray test and electrochemical impedance spectroscopy （EIS） techniques. The self-corrosion current density （icorr） and the polarization resistance （Rp） of Ni-P/TiO2 film are 0.22 μA/cm2 （about 14% of that of Ni-P coating）,and 120 kΩ·cm2 （about 2 times of that of Ni-P coating）,respectively. The anti-salt spray time of Ni-P/TiO2 film is about 2.5 times of that of the Ni-P coating. The results indicate that Ni-P/TiO2 film has a better corrosion resistance than Ni-P coating,and the composite film increases the corrosion resistance of NdFeB magnet markedly.

Photocatalytic properties of P25-doped TiO_2 composite film synthesized via sol–gel method on cement substrate

TiO2 films have received increasing attention for the removal of organic pollutants via photocatalysis. To develop a simple and effective method for improving the photodegradation efficiency of pollutants in surface water, we herein examined the preparation of a P25-TiO2 composite film on a cement substrate via a sol–gel method. In this case, Rhodamine B（Rh B）was employed as the target organic pollutant. The self-generated TiO2 film and the P25-TiO2 composite film were characterized by X-ray diffraction（XRD）, N2 adsorption/desorption measurements, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, and diffuse reflectance spectroscopy（DRS）. The photodegradation efficiencies of the two films were studied by Rh B removal in water under UV（ultraviolet） irradiation. Over 4 day exposure, the P25-TiO2 composite film exhibited higher photocatalytic performance than the self-generated TiO2 film. The photodegradation rate indicated that the efficiency of the P25-TiO2 composite film was enhanced by the addition of the rutile phase Degussa P25 powder. As such, cooperation between the anatase TiO2 and rutile P25 nanoparticles was beneficial for separation of the photo-induced electrons and holes. In addition, the influence of P25 doping on the P25-TiO2 composite films was evaluated. We found that up to a certain saturation point, increased doping enhanced the photodegradation ability of the composite film. Thus, we herein demonstrated that the doping of P25 powders is a simple but effective strategy to prepare a P25-TiO2 composite film on a cement substrate, and the resulting film exhibits excellent removal efficiency in the degradation of organic pollutants.

Mesocrystalline TiO2/sepiolite composites for the effective degradation of methyl orange and methylene blue

Mesocrystalline TiO2/sepiolite （TiS） composites with the function of adsorption and degradation of liquid organic pollutants were successfully fabricated via a facile and low-cost solvothermal reaction. The prepared TiS composites were characterized by FESEM, HRTEM, XRD, XPS, N2 adsorption-desorption, UV-vis DRS, and EPR. Results revealed the homogeneous dispersion of highly reactive TiO2 mesocrystals on the sepiolite nanofibers. Thereinto each single-crystal-like TiO2 mesocrystal comprised many [001]-oriented anatase nanoparticles about 10-20 nm in diameter. The photocatalytic activity was further evaluated by the degradation of anionic dye （methyl orange） and cationic dye （methylene blue） under the UV-vis light （350≤λ≤780 nm） irradiation. By selecting appropriate experimental conditions, we can easily manipulate the photocatalytic performance of TiS composites. The optimal TiS catalyst （the sepiolite content of 28.5 wt.%, and the reaction time of 24 h） could efficiently degrade methyl orange to 90.7% after 70 min, or methylene blue to 97.8% after 50 min, under UV-vis light irradiation. These results can be attributed to their synergistic effect of high crystallinity, large specific surface area, abundant hydroxyl radicals, and effective photogenerated charge separation.

Preparation and photoelectrochemical performance of TiO_2/Ag_2Se interface composite film

Coupling TiO2 with a narrow band gap semiconductor acting as the photosensitizer has attracted much attention in solar energy exploitation. In this work,the porous TiO2 film was first formed on the conducting glass plate (CGP) substrate by the decomposition of polyethylene glycol (PEG) mixing in titanium hydroxide sol at 450℃. Then,the TiO2/Ag2Se interface composite film was fabricated by interface reaction of AgNO3 with NaSeSO3 on the activated surface of porous TiO2 film. The results of SEM and XRD analyses indicated that the porous TiO2 layer was made up of the anatase crystal,and the Ag2Se layer was made up of congregative small particles that have low-temperature α-phase structure. Due to its efficient charge separation for the photo-induced electron-hole pairs,the TiO2/Ag2Se interface composite film as-prepared has good photovoltaic property and high photocurrent response for visible light,which have been confirmed by the photoelectrochemical measurements.

Preparation and characterization of CoFe_2O_4/TiO_2 magnetic composite films

CoFe2O4/TiO2 magnetic composite films were prepared using the sol-gel method with tetrabutyltitanate and metallic chlorates as starting materials. The effects of heat treatment temperatures on micro- structures and on magnetic properties were studied. The microstructure and properties of the samples at different heat treatment temperatures were characterized by X-ray diffraction, Raman spectrum, scanning electron microscopy, polarized microscopy and vibrating sample magnetometry. The results show that crystals of different substances grow up independently. Cobalt ferrite is evenly embedded into the titanium dioxide matrix in the prepared composite films. The magnetism of the composite films is enhanced with an increase of the heat temperature.

A Composite Photoanode Based on P25/TiO2 Nanotube Arrays/ Flower-Like TiO2 for High-Efficiency Dye-Sensitized Solar Cells

In this work, a three-layer TiO2 composite film consisting of flower-like TiO2 （Flo-TiO2） as overlayer, TiOa nanotube arrays as interlayer and TiO2 nanoparticle （P25） as underlayer was fabricated as the photoelectrode of dyesensitized solar cells （DSSCs）. Due to the introduction of Flo-TiO2, the three-layer composite film has strong lightscattering ability. Then, we have investigated and compared the photoelectric conversion properties of DSSCs based on three-layer structure （P25/TNT arrays/Flo-TiO2） photoelectrode and double-layer film （P25/TNT arrays） photoelectrode. It is found that DSSCs based on three-layer structure exhibit a high power conversion efficiency of 6.48% compared with the DSSCs composed of double-layer film （5.11%）.