Papers by Keyword: TiO₂ Film

Abstract: In order to improve the photocatalytic efficiency, the N doped anodic titania film for photocatalyst was synthesized by anodic oxidation of TiN layer in sulfuric electrolyte, and the photocatalytic properties of N doped TiO₂ layer were investigated. During the oxidation process of the TiN layer, nitrogen was doped into the anodic titania film due to the change of the titanium nitride layer to TiO₂ layer film. In the evaluation of dye degradation, N doped titania catalyst shows much higher efficiency than non-doped titania film.

Abstract: TiO2 films consisting of rod-like to sphere-like TiO2 particles on glass slides were synthesized by assembly technique. The results showed that the shape and size of TiO2 particles could be manipulated using different concentrations of polyethylene glycol 20000. By increasing of PEG, the shapes of the TiO2 particles transformed from rod-like to sphere-like, the size of TiO2 particles became gradually smaller. The size became bigger when an excess amount of PEG was added. With the adding of PEG，the amount of the TiO2 , the hydroxyl content, and the rutile phase content on the surface of TiO2 films increased, respectively. The photocatalytic activity of TiO2 films added PEG was higher than that of unadded samples.

Abstract: TiO2 films with three-dimensional web-like structure have been prepared by the photo polymerization-induced phase separation method (PIPS). Scanning electron microscopy and X-ray diffraction were used to characterize the as-prepared TiO2 films. The results showed that the film texture could be tuned by changing the composition of the precursor solution. The TiO2 film with web-like structure exhibited high photocatalytic activity for the degradation of methylene blue (MB) dye. The as-prepared films were used as the photo-anodes in dye-sensitized solar cells (DSCs). The photoelectric conversion efficiency of the DSCs was significantly enhanced by changing the POGTA/TTB in the precursor solution. Because of the increased dye adsorption active sites and efficient electron transport in the TiO2 anode film, a photoelectric conversion efficiency of 3.015% was obtained.

Abstract: In order to find an effective way to degrade the effluent, the Cu/TiO2, La/TiO2, Cr/TiO2 films with unique 3-D network structures were prepared using Ti(OBu)4 by sol-gel method loaded on the gauzes. These films structures were characterized by means of XRD and SEM. The effects of doped TiO2 films and combination of magnetic field and doped TiO2 films on the degradation of methyl orange (MO) were studied. The results indicated that after combinating the magnetic field, the photocatalysis efficiency of doped TiO2 films have been improved,especially the influence on Cu/TiO2 film was more obvious than other films.When magnetic intensity was around 30mT ,the MO degradation ratio went up to 60% by using Cu/TiO2 films.But the influences of magnetic intensity on photocatalytic activities of doped TiO2 films had a maximum value which was 30mT.

Abstract: The treatment of highly colored wastewater containing hazardous industrial chemicals and dyes is one of the growing needs of the present time. To meet the motive in the present work, TiO₂ was immobilized on glass slides using heat method and acrylic binder. Heat method involves the preparation of suspension of powdered TiO₂ and then brushing the suspension on the surface of glass slides. The slides were then calcined at high temperature for attachment of TiO₂ to the glass surface. The acrylic binder method of immobilization involves preparation of acrylic emulsion and using the same to attach the TiO₂ particles to the fiber glass slides. The preared films were then characterized using XRD and SEM. The photocatalytic performance of the prepared films for degradation of Acid Red 27 dye in sunlight was evaluated and compared. The films formed with the help of heat treatment method showed better dye degradation capabilities.

Abstract: A new hydrothermal method was introduced to prepare TiO2 films. The films were prepared by using tetrabutyl titanate as precursor, toluene as solvent and hydrochloric acid as the inhibitor via a facile hydrothermal method. XRD, SEM, AFM, and TG-DSC were used to characterize phase structure and morphology of TiO₂ thin films. XRD analysis showed that crystal phase of as- prepared films were anatase entirely,and its average size was 9 nm. AFM and SEM analysis indicated that films had nanocrystallines,and it was homogenous,dense and crack- free. Photocatalytic properties of TiO2 film were estimated by degradation of methylene blue . The result shows that the degradation rate of 40mL methylene blue solution with initial concentration 10 mg/L reaches to 52.8 % after irradiated for 120 min under 35W ultraviolet lamp ,and as-prepared TiO2 film has better photocatalytic property.

Abstract: The TiO2 films with hierarchical structure consisting of porous structure and spinodal phase separation structure have been synthesized by sol-gel method. The influence of the different photomonomers, different coating times and different heat treatment temperatures on the structure and photocatalytic activity of TiO2 film has been investigated and the possible mechanism was proposed. The performances of as-prepared TiO2 films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD). The photocatalytic activities of the as-prepared TiO2 films have been carried out by the degradation of methylene blue (MB) dye under the UV irradiation. The results indicated that the as-prepared TiO2 film with hierarchical structure exhibited significant photocatalytic activity, which might be due to its high specific surface area and high-speed electron migration that enhanced the subsequent photocatalytic reactions and led to a positive synergistic effect.

Abstract: Electron beam melting (EBM) method is one of the free-form fabrication techniques that enable near-net-shape manufacturing of complex three-dimensional, porous, and graded products, and is expected to facilitate the development of new methods for manufacturing biomaterials that could be used for hard-tissue substitutes. Titanium and its alloys have been used widely as biomaterials for hard-tissue substitutes because of their excellent mechanical properties and biocompatibility. However, the osteointegration of these materials is less than that of bioactive ceramics. Therefore, various surface-modification techniques have been developed to improve the osteointegration. The simplest way is to synthesize bioactive ceramic films on the surface of titanium or its alloys. The purpose of the present work was to synthesize a bioactive TiO₂ film on Ti-6Al-4V (hereafter, abbreviated as Ti-64) substrates fabricated from powders using the EBM method and treated by a combination of chemical and hydrothermal treatment. Ti-64 plates fabricated by the EBM method were chemically treated with a H₂O₂/HNO₃ aqueous solution under appropriate conditions. The plates were then hydrothermally treated with a NH₃ aqueous solution. TiO₂-gel films were produced by chemical treatment with a H₂O₂/HNO₃ aqueous solution on the surface of a Ti-64 substrate. Anatase-type TiO₂ films with high crystallinity were synthesized by the hydrothermal treatment of the TiO₂-gel films.

Abstract: Mesoporous solid TiO₂ film (2-50nm) offering large specific surface area and well connected cavities have been researched extensively in the last decade, aiming to enhance photo-conversion efficiency in the dye-sensitised solar cells (DSSCs). The efficiency of DSSCs is highly sensitive to surface morphology, crystallinity and porosity of the TiO2 film which are in turn dependent upon processing temperature. Multilayered porous TiO₂ films were synthesised under different temperature regimes using sol-gel method in combination with spin coating. The influence of temperature variation on the films morphology, crystallinity, and its interfacial adhesiveness to the substrate was studied. A modified method of pre-curing temperature was employed, in order to attain firm adhesiveness of the film to the Fluorine-doped Tin Oxide (FTO) glass substrate. The films prepared by different pre-curing temperature protocols were incorporated into DSSCs for evaluating the affect of varying temperature on photo-conversion efficiency of the cells.

Abstract: TiO2 films were deposited on AZ31 magnesium alloy substrates by r.f. magnetron sputtering. The corrosion behaviors in simulated body fluid (SBF) of the film samples were investigated and compared to the bare AZ31 magnesium alloy. After 3 days’ corrosion in SBF, only part of the TiO2 layer suffered from corrosion and the substrate was prevented from corrosion. In contrast, the bare magnesium alloy suffered from severe corrosion. After 10 days’ corrosion, the TiO2 layer was penetrated and the substrates still did not suffer from corrosion. After 15 days’ corrosion, besides TiO2 layer, the substrate suffered from corrosion to some degree. The depth of the corrosion layer is about 6 m, which is far lower than that of bare magnesium alloy, 40 m. The results show that TiO2 films effectively improve the corrosion properties of magnesium alloys.