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 （...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.展开更多
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...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.展开更多
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 ...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.展开更多
A new TiO2 modified film on carbon steel was prepared by electroless plating and sol gel composite process. An artificial neural net was used to optimize the preparing condition of the film. The optimized condition of...A new TiO2 modified film on carbon steel was prepared by electroless plating and sol gel composite process. An artificial neural net was used to optimize the preparing condition of the film. The optimized condition of the TiO2-modified film on carbon steel is as follows： plating time of NiP is 50 min, number of dip coating is 4, heat treatment time is 2 h, and the molar ratio of complexing reagent to Ti（OC4 H9）4 is 1.5 ： 1. Corrosion behavior of carbon steel with coating was investigated by polarization resistance measurement, anode polarization, EIS and ESEM measurement. XPS was used to characterize the element valence of the modified film. Results show that carbon steel with TiO2 modified film has good corrosion resistance in 0.5 mol/L of H2SO4 solution and 0.5 mol/L of NaCl solution. It is also found that the preparing condition of forming TiO2-modified film can be obtained easily by the artificial neural net.展开更多
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 i...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.展开更多
TiO2 mesocrystals can considerably enhance charge separation owing to their oriented superstructures,with fewer internal defects and porous properties providing more active sites.In this work,we prepared TiO2 mesocrys...TiO2 mesocrystals can considerably enhance charge separation owing to their oriented superstructures,with fewer internal defects and porous properties providing more active sites.In this work,we prepared TiO2 mesocrystal films by a direct annealing method.The morphology and crystal phase of the film were controlled by adjusting the ratio of NH4F and the calcination temperature.Moreover,we found that Au nanoparticles loaded on a TiO2 mesocrystal film enabled highly efficient visible light photocatalytic properties.The photocatalytic activities were studied by hydrogen generation and photoreduction of Cr(VI).This work represents a considerable advance in the development and application of the TiO2 mesocrystals.展开更多
Anatase TiO2 films were successfully prepared on foam nickel substrates by sol-gel technique using tetrabutyl titanate as precursor. The characteristics of the TiO2 films were investigated by XPS, XRD, FE-SEM, TEM and...Anatase TiO2 films were successfully prepared on foam nickel substrates by sol-gel technique using tetrabutyl titanate as precursor. The characteristics of the TiO2 films were investigated by XPS, XRD, FE-SEM, TEM and UV-Vis absorption spectra. The photocatalytic activities of TiO2 films were investigated by photocatalytic degradation reactions of gaseous acetaldehyde, an indoor pollutant, under ultraviolet light irradiation. It was found that Ni^2＋ doping into TiO2 films due to the foam nickel substrates resulted in the extension of absorption edges of TiO2 films from UV region to visible light region. The pre-heating for foam nickel substrates resulted in the formation of NiO layer, which prevented effectively the injection of photogenerated electrons from TiO2 films to metal nickel. The TiO2 films displayed high photocatalytic activity for the degradation of acetaldehyde, and were enhanced by calcining the substrates and coating TiO2 films repeatedly. The high activity was mainly attributed to the improvement of the characteristics of substrate surface and the increase of active sites on photocatalyst.展开更多
TiO2 films were deposited at room temperature by DC pulse magnetron sputtering system.The crystalline structures,morphological features and photocatalytic activity of TiO2 films were systematically investigated by X-r...TiO2 films were deposited at room temperature by DC pulse magnetron sputtering system.The crystalline structures,morphological features and photocatalytic activity of TiO2 films were systematically investigated by X-ray diffraction（XRD）,atomic force microscopy（AFM） and ultraviolet spectrophotometer,respectively.The results indicated that working pressure was the key deposition parameter in？uencing the TiO2 film phase composition at room temperature,which directly affected its photocatalytic activity.With increasing working pressure,the target self-bias decreases monotonously.Therefore,low temperature TiO2 phase（anatase） could be deposited with high working pressure.The anatase TiO2 films deposited with 1.4 Pa working pressure displayed the highest photocatalytic activity by the decomposition of Methyl Orange solution,which the degradation rate reached the maximum（35%） after irradiation by ultraviolet light for 1 h.展开更多
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 process...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.展开更多
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 c...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.展开更多
Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, p...Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, photocathodic protection and photoelectrochemical properties of TiO2 thin films were investigated. It is indicated that the photoelectrical performance of the Zn?TiO2 films is enhanced with the addition of Zn element compared with the pure-TiO2 film and the largest decline by 897 mV in the electrode potential is achieved under 300 °C heat treatment. SEM?EDS analyses show that Zn element is unevenly distributed in Zn?TiO2 films; XRD patterns reveal that the grain size of Zn?TiO2 is smaller than that of pure-TiO2; FTIR results indicate that Zn - O bond forms on Zn?TiO2 surface. Ultraviolet visible absorption spectra prove that Zn?TiO2 shifts to visible light region.Mott?Shottky curves show that the flat-band potential of Zn?TiO2 is more negative and charge carrier density is bigger than that ofpure-TiO2, implying that under the synergy of the width of the space-charge layer, carrier density and flat-band potential, Zn?TiO2 with 300 °C heat treatment displays the best photocathodic protection performance.展开更多
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-c...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.展开更多
TiO2 film modified by Bi2O3 microgrid array was successfully fabricated by using a microsphere lithography method.The structure and morphology of TiO2 film,Bi2O3 film and TiO2 film/Bi2O3 microgrid heterojunction were ...TiO2 film modified by Bi2O3 microgrid array was successfully fabricated by using a microsphere lithography method.The structure and morphology of TiO2 film,Bi2O3 film and TiO2 film/Bi2O3 microgrid heterojunction were characterized through X-ray diffraction,atomic force microscopy and scanning electron microscopy.The optical transmittance spectra and the photocatalytic degradation capacity of these samples to rhodamine B were determined via ultraviolet-visible spectroscopy.The results indicated that the coupled system showed higher photocatalytic activity than pure TiO2 and Bi2O3 films under xenon lamp irradiation.The enhancement of the photocatalytic activity was ascribed to the special structure,which could improve the separation of photo-generated electrons and holes,enlarge the surface area and extend the response range of TiO2 film from ultraviolet to visible region.展开更多
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 （XR...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.展开更多
Anatase TiO2 sol was synthesized under mild conditions （75℃ and ambient pressure） by hydrolysis of titaniumn-butoxide in abundant acidic aqueous solution and subsequent reflux to enhance crystallization. At room te...Anatase TiO2 sol was synthesized under mild conditions （75℃ and ambient pressure） by hydrolysis of titaniumn-butoxide in abundant acidic aqueous solution and subsequent reflux to enhance crystallization. At room temperature and in ambient atmosphere, crystalline TiO2 thin films were deposited on polymethylmethacrylate （PMMA）, SiO2-coated PMMA and SiO2-coated silicone rubber substrates from the as-prepared TiO2 sol by a dip-coating process. SiO2 layers prior to TiO2 thin films on polymer substrates could not only protect the substrates from the photocatalytic decomposition of the TiO2 thin films but also enhance the adhesion of the TiO2 thin films to the substrates. Field-emission type scanning electron microscope （FE-SEM） investigations revealed that the average particle sizes of the nanoparticles composing the TiO2 thin films were about 35-47 nm. The TiO2 thin films exhibited high photocatalytic activities in the degradation of reactive brilliant red dye X-3B in aqueous solution under aerated conditions. The preparation process of photocatalytic TiO2 thin films on the polymer substrates was quite simple and a low temperature route.展开更多
We synthesized a mesoporous film based on TiO2-reduced graphene oxide(RGO)hybrids using a one-step vapor-thermal method without the need for an additional annealing process.The vapor-thermally prepared TiO2-graphene h...We synthesized a mesoporous film based on TiO2-reduced graphene oxide(RGO)hybrids using a one-step vapor-thermal method without the need for an additional annealing process.The vapor-thermally prepared TiO2-graphene hybrid(VTH)features unique structures with an ultra-large specific surface area of^260 m^2 g^-1 and low aggregation,giving rise to enhanced light harvesting and increased charge generation and separation efficiency.It was observed that a mesoporous film with uniform pore distribution is simultaneously obtained during the VTH growth process.When a 5.0 wt%RGO VTH film was used as the active layer in photocatalysis,the highest photocatalytic activity for degradation of methyl orange was achieved.For another,when a 0.75 wt%RGO VTH film was used as the photoanode in a dye-sensitized solar cell,the power conversion efficiency reached 7.58%,which represents an increase of 73.1%compared to a solar cell using an a photoanode of pure TiO2 synthesized by a traditional solvothermal method.It is expected that this facile method for the synthesis of TiO2/graphene hybrid mesoporous films will be useful in practical applications for preparing other metal oxide/graphene hybrids with ultra-high photocatalytic activity and photovoltaic performance.展开更多
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 show...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.展开更多
Three thicknesses of TiO2 films, 174, 195, and 229 nm, were deposited onto quartz substrates by sol–gel spin coating method. The as-deposited thin films were characterized by nano-crystallite with different sizes (19...Three thicknesses of TiO2 films, 174, 195, and 229 nm, were deposited onto quartz substrates by sol–gel spin coating method. The as-deposited thin films were characterized by nano-crystallite with different sizes (19–46 nm) and relatively high porous structure. Optical constants were determined and showed the lowest refractive index of 1.66 for the as-prepared films that ever reported till now. Obtained results were discussed through current theoretical ideas.展开更多
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, hi...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.展开更多
基金Project(gf200901002)supported by the Open Research Fund of National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology of Nanchang Hangkong University,China
文摘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.
基金Project(21471054)supported by the National Natural Science Foundation of China
文摘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.
基金Project (2010JQ6008) supported by the Natural Science Foundation of Shaanxi Province,China
文摘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.
文摘A new TiO2 modified film on carbon steel was prepared by electroless plating and sol gel composite process. An artificial neural net was used to optimize the preparing condition of the film. The optimized condition of the TiO2-modified film on carbon steel is as follows： plating time of NiP is 50 min, number of dip coating is 4, heat treatment time is 2 h, and the molar ratio of complexing reagent to Ti（OC4 H9）4 is 1.5 ： 1. Corrosion behavior of carbon steel with coating was investigated by polarization resistance measurement, anode polarization, EIS and ESEM measurement. XPS was used to characterize the element valence of the modified film. Results show that carbon steel with TiO2 modified film has good corrosion resistance in 0.5 mol/L of H2SO4 solution and 0.5 mol/L of NaCl solution. It is also found that the preparing condition of forming TiO2-modified film can be obtained easily by the artificial neural net.
文摘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.
文摘TiO2 mesocrystals can considerably enhance charge separation owing to their oriented superstructures,with fewer internal defects and porous properties providing more active sites.In this work,we prepared TiO2 mesocrystal films by a direct annealing method.The morphology and crystal phase of the film were controlled by adjusting the ratio of NH4F and the calcination temperature.Moreover,we found that Au nanoparticles loaded on a TiO2 mesocrystal film enabled highly efficient visible light photocatalytic properties.The photocatalytic activities were studied by hydrogen generation and photoreduction of Cr(VI).This work represents a considerable advance in the development and application of the TiO2 mesocrystals.
基金Project supported by the Special Foundation of Nanometer Technology from Shanghai Municipal Science and Technology Commis-sion(STCSM) (No. 0552nm002).
文摘Anatase TiO2 films were successfully prepared on foam nickel substrates by sol-gel technique using tetrabutyl titanate as precursor. The characteristics of the TiO2 films were investigated by XPS, XRD, FE-SEM, TEM and UV-Vis absorption spectra. The photocatalytic activities of TiO2 films were investigated by photocatalytic degradation reactions of gaseous acetaldehyde, an indoor pollutant, under ultraviolet light irradiation. It was found that Ni^2＋ doping into TiO2 films due to the foam nickel substrates resulted in the extension of absorption edges of TiO2 films from UV region to visible light region. The pre-heating for foam nickel substrates resulted in the formation of NiO layer, which prevented effectively the injection of photogenerated electrons from TiO2 films to metal nickel. The TiO2 films displayed high photocatalytic activity for the degradation of acetaldehyde, and were enhanced by calcining the substrates and coating TiO2 films repeatedly. The high activity was mainly attributed to the improvement of the characteristics of substrate surface and the increase of active sites on photocatalyst.
基金supported by the Dalian Foundation for Development of Science and Technology (No.2006A13GX029)
文摘TiO2 films were deposited at room temperature by DC pulse magnetron sputtering system.The crystalline structures,morphological features and photocatalytic activity of TiO2 films were systematically investigated by X-ray diffraction（XRD）,atomic force microscopy（AFM） and ultraviolet spectrophotometer,respectively.The results indicated that working pressure was the key deposition parameter in？uencing the TiO2 film phase composition at room temperature,which directly affected its photocatalytic activity.With increasing working pressure,the target self-bias decreases monotonously.Therefore,low temperature TiO2 phase（anatase） could be deposited with high working pressure.The anatase TiO2 films deposited with 1.4 Pa working pressure displayed the highest photocatalytic activity by the decomposition of Methyl Orange solution,which the degradation rate reached the maximum（35%） after irradiation by ultraviolet light for 1 h.
文摘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.
基金Sponsored by Hi-Tech Research and Development Program of China (2003AA305120)
文摘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.
基金Project(cstc2011jj A50008)supported by the Natural Science Foundation of Chongqing,ChinaProject(14ZB0025)supported by Education Department of Sichuan Province,China
文摘Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, photocathodic protection and photoelectrochemical properties of TiO2 thin films were investigated. It is indicated that the photoelectrical performance of the Zn?TiO2 films is enhanced with the addition of Zn element compared with the pure-TiO2 film and the largest decline by 897 mV in the electrode potential is achieved under 300 °C heat treatment. SEM?EDS analyses show that Zn element is unevenly distributed in Zn?TiO2 films; XRD patterns reveal that the grain size of Zn?TiO2 is smaller than that of pure-TiO2; FTIR results indicate that Zn - O bond forms on Zn?TiO2 surface. Ultraviolet visible absorption spectra prove that Zn?TiO2 shifts to visible light region.Mott?Shottky curves show that the flat-band potential of Zn?TiO2 is more negative and charge carrier density is bigger than that ofpure-TiO2, implying that under the synergy of the width of the space-charge layer, carrier density and flat-band potential, Zn?TiO2 with 300 °C heat treatment displays the best photocathodic protection performance.
基金Supported by the Natural Science Foundation of Jiangsu Province (JH01-010).
文摘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.
基金supported by the National High Technology Research and Development Program of China under Grant 2009AA03Z428the National Natural Science Foundation of China under Grant No. 50872005the National Basic Research Program of China under Grant 2007CB613306
文摘TiO2 film modified by Bi2O3 microgrid array was successfully fabricated by using a microsphere lithography method.The structure and morphology of TiO2 film,Bi2O3 film and TiO2 film/Bi2O3 microgrid heterojunction were characterized through X-ray diffraction,atomic force microscopy and scanning electron microscopy.The optical transmittance spectra and the photocatalytic degradation capacity of these samples to rhodamine B were determined via ultraviolet-visible spectroscopy.The results indicated that the coupled system showed higher photocatalytic activity than pure TiO2 and Bi2O3 films under xenon lamp irradiation.The enhancement of the photocatalytic activity was ascribed to the special structure,which could improve the separation of photo-generated electrons and holes,enlarge the surface area and extend the response range of TiO2 film from ultraviolet to visible region.
基金financially supported by the National Natural Science Foundation of China (No.51301118)the Projects of International Cooperation in Shanxi (No.2014081002)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (No.2013108)
文摘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.
文摘Anatase TiO2 sol was synthesized under mild conditions （75℃ and ambient pressure） by hydrolysis of titaniumn-butoxide in abundant acidic aqueous solution and subsequent reflux to enhance crystallization. At room temperature and in ambient atmosphere, crystalline TiO2 thin films were deposited on polymethylmethacrylate （PMMA）, SiO2-coated PMMA and SiO2-coated silicone rubber substrates from the as-prepared TiO2 sol by a dip-coating process. SiO2 layers prior to TiO2 thin films on polymer substrates could not only protect the substrates from the photocatalytic decomposition of the TiO2 thin films but also enhance the adhesion of the TiO2 thin films to the substrates. Field-emission type scanning electron microscope （FE-SEM） investigations revealed that the average particle sizes of the nanoparticles composing the TiO2 thin films were about 35-47 nm. The TiO2 thin films exhibited high photocatalytic activities in the degradation of reactive brilliant red dye X-3B in aqueous solution under aerated conditions. The preparation process of photocatalytic TiO2 thin films on the polymer substrates was quite simple and a low temperature route.
文摘We synthesized a mesoporous film based on TiO2-reduced graphene oxide(RGO)hybrids using a one-step vapor-thermal method without the need for an additional annealing process.The vapor-thermally prepared TiO2-graphene hybrid(VTH)features unique structures with an ultra-large specific surface area of^260 m^2 g^-1 and low aggregation,giving rise to enhanced light harvesting and increased charge generation and separation efficiency.It was observed that a mesoporous film with uniform pore distribution is simultaneously obtained during the VTH growth process.When a 5.0 wt%RGO VTH film was used as the active layer in photocatalysis,the highest photocatalytic activity for degradation of methyl orange was achieved.For another,when a 0.75 wt%RGO VTH film was used as the photoanode in a dye-sensitized solar cell,the power conversion efficiency reached 7.58%,which represents an increase of 73.1%compared to a solar cell using an a photoanode of pure TiO2 synthesized by a traditional solvothermal method.It is expected that this facile method for the synthesis of TiO2/graphene hybrid mesoporous films will be useful in practical applications for preparing other metal oxide/graphene hybrids with ultra-high photocatalytic activity and photovoltaic performance.
基金This work was financially supported by the Combined Project between the Educational Commission and the Economic Commission of Gansu Province (Nos. 99CX-04, 0310B-08)the Natural Science Foundation of Gansu Province (No. 3ZS041-A25-028)the Invention Project of Science & Technology (No. KJCXGC-01, NWNU), China.
文摘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.
文摘Three thicknesses of TiO2 films, 174, 195, and 229 nm, were deposited onto quartz substrates by sol–gel spin coating method. The as-deposited thin films were characterized by nano-crystallite with different sizes (19–46 nm) and relatively high porous structure. Optical constants were determined and showed the lowest refractive index of 1.66 for the as-prepared films that ever reported till now. Obtained results were discussed through current theoretical ideas.
基金This work was supported by the National Natural Science Foundation of China(No,50376067)the Plan for Science&Technology Development of Guangzhou(2001-Z-117-01).
文摘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.
