Ta-containing TiO2 films with Ta contents of 5%, 20%, 33% （mole fraction） were sol-gel coated on the surface roughened Ti6AI4V alloy by dip coating method for biomedical applications. The Ta-TiO2 films on 1.5 mol/L ...Ta-containing TiO2 films with Ta contents of 5%, 20%, 33% （mole fraction） were sol-gel coated on the surface roughened Ti6AI4V alloy by dip coating method for biomedical applications. The Ta-TiO2 films on 1.5 mol/L NaOH-HCI pretreated substrate are adherent, but there are cracks for the sample with 33% Ta. X-ray photoelectron spectroscopy results show that Ti and Ta exist as TiP2 and Ta205 in the film, and A1 element is not detectable. X-ray diffraction and Raman scattering analyses reveal that the addition of Ta decreases crystallization of the films. Potentiodynamic polarization test in a Ca-free Hank＇s balanced solution demonstrates that the coating samples markedly improve the corrosion resistance compared with the polished sample. The addition of Ta impedes UV light-induced hydrophilic conversion of the coating samples. The sample with 20% Ta has enough film integrity and hydrophilic conversion rate, and is expected to possess good biological properties.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
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 ...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.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
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 ...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.展开更多
In order to improve the corrosion resistance and biocompatibility of NiTi surgical alloy, TiO2 and TiO2-SiO2 thin films were prepared by sol-gel method. The surface characteristics of the film, which include surface c...In order to improve the corrosion resistance and biocompatibility of NiTi surgical alloy, TiO2 and TiO2-SiO2 thin films were prepared by sol-gel method. The surface characteristics of the film, which include surface composition, microstructure and surface morphology, were studied by X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectra (XPS), respectively. A scratching test was used to assess the interface adhesive strength between the film and substrate. The corrosion resistance of NiTi alloy coated with oxide films were studied by anodic polarization curves measurement in biological solution. Additionally, a preliminary study of the in vitro bioactivity of the films was conducted. The results indicated that TiO2 and TiO2-SiO2 (Ti/Si=4:1) films have higher electrochemical corrosion resistance and can be used as protective layers on NiTi alloy. In addition, TiO2-SiO2 composite films have better bioactivity than TiO2 film.展开更多
Gold nanoparticles dispersed Y2O3 films were prepared through a sol-gel method by using yttrium acetate and Au nanoparticles colloid as precursors. The films were characterized by X-ray diffraction （XRD）, transmissi...Gold nanoparticles dispersed Y2O3 films were prepared through a sol-gel method by using yttrium acetate and Au nanoparticles colloid as precursors. The films were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and UV-VIS absorption spectra. XRD patterns and TEM images of Y2O3 ＋ Au films give the same resuits on structure and particle size as that of pure Y2O3 films. The surface plasma resonance （SPR） of Au nanoparticles in Y2O3 ＋ Au film was observed around 550 nm in the absorption spectrum and its position shifts to red with increasing annealing temperature is caused by the increase of dielectric constant of Y2O3 matrix and the size of Au nanoparticles. The second and third order nonlinear optical effects of Y2O3 ＋ Au films were also observed. The photoluminescent properties of Y2O3 ： Eu ＋ Au films were investigated and results indicate that there exist an energy transfer from Eu^3 ＋ to Au nanoparticles and this energy transfer decreases the emission of Eu^3 ＋ in Y2O3 ： Eu ＋ Au film.展开更多
Porous TiO2 thin films were prepared from alkoxide solutions with and without polyethylene glycol (PEG) by sol-get route on soda lime glass, and were characterized by atomic force microscopy (AFM), transmission electr...Porous TiO2 thin films were prepared from alkoxide solutions with and without polyethylene glycol (PEG) by sol-get route on soda lime glass, and were characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that TiO2 film prepared from precursor solution without PEG is composed of spherical particles of about 100 nm and several nanometer mesoporous pores. With the increase of the amount of PEG added to the precursor solution, the diameter and the depth of the pores in the resultant films increas on the decomposition of PEG during heat-treatment, which lead to them increase of the surface roughness of the films. XRD and TEM results show that the single anatase phase is precipitated and there are some orientation effects in (101) direction.展开更多
In this study, vanadium doped TiO2 thin films were deposited on glass substrates using a sol-gel dip-coating process. X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Vis spectrophotomete...In this study, vanadium doped TiO2 thin films were deposited on glass substrates using a sol-gel dip-coating process. X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Vis spectrophotometer were used to characterize the structural, chemical and the optical properties of the thin films. The photo-catalytic activities of films were investigated by methylene blue degradation. Water contact angle on the film surfaces was measured by a water contact angle analyzer. The results indicated that vanadium doping had a significant effect on the self-cleaning properties of TiO2 thin films.展开更多
Pure TiO2 thin films and iron doped TiO2 thin films on glass substrate were prepared by sol-gel method, and characterized by X-ray diffractometer （XRD）, thermo-gravimetric analysis （TG-DSC）, high resolution transm...Pure TiO2 thin films and iron doped TiO2 thin films on glass substrate were prepared by sol-gel method, and characterized by X-ray diffractometer （XRD）, thermo-gravimetric analysis （TG-DSC）, high resolution transmission electron microscope （HRTEM）, scanning electron microscope （SEM） and UV-Vis spectroscopy, respectively. The experimental results show that the pure TiO2 thin films and iron doped TiO2 thin films can destroy most of the escherichia coli and bacillus subtillis under the irradiation of 365 nm UV-light. However, the iron doped TiO2 thin film is a better photocatalyst than pure TiO2 thin film. The ultrastructural studies provide direct evidences for understanding the bactericidal mechanism of the TiO2 photocatalyst.展开更多
Delafossite structured p-type wide bandgap semiconductor, CuYO<sub>2</sub> thin films were prepared on SiO<sub>2</sub> substrate by sol-gel method using copper (II) acetate and yttrium (III) ac...Delafossite structured p-type wide bandgap semiconductor, CuYO<sub>2</sub> thin films were prepared on SiO<sub>2</sub> substrate by sol-gel method using copper (II) acetate and yttrium (III) acetate as source materials. The films preparation process was studied by varying annealing temperature after the preparation of gel films by spin coating, followed by thermal annealing at higher temperature. In the present work, one step annealing directly from Cu-Y-gel under nitrogen flow was used. X-ray diffraction (XRD) revealed that the film annealed at 800<sup>。</sup>C is significantly c-axis oriented, shows only (002) and (004) peaks at 15.6<sup>。</sup> and 31.5<sup>。</sup>, respectively. The optical bandgap of 3.7 - 3.8 eV is estimated by (αhν)2 plot which is higher than previous works. In addition, the films with highly c-axis orientation showed photoluminescence (PL) at room temperature with very broad peak at 2.3 eV. The films annealed at different temperature showed different structural properties.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
Y2O3：Er^3＋ films were prepared by a simple sol-gel process. The structural properties of Y2O3：Er^3＋ films were characterized with X-ray diffraction, Fourier transform infrared spectroscopy and field emission scann...Y2O3：Er^3＋ films were prepared by a simple sol-gel process. The structural properties of Y2O3：Er^3＋ films were characterized with X-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The results indicated that the Y2O3：Er^3＋ films might have high upconversion efficiency because of their low vibrational energy. Under 785 and 980 nm laser excitation, the samples showed green （^2H11/2→^4I15/2, ^4S3/2→^4I15/2） and red （^4F9/2→^4I15/2） upconversion emissions. The upconversion mechanisms were studied in detail through laser power dependence. Excited state absorption and energy transfer process were discussed as possible upconversion mechanisms. The cross relaxation process in Er^3＋ was also investigated.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
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 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.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
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...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.展开更多
基金Project(xjj2011096)supported by the Fundamental Research Fund for the Central Universities,ChinaProjects(50901058,51374174)supported by the National Natural Science Foundation of China
文摘Ta-containing TiO2 films with Ta contents of 5%, 20%, 33% （mole fraction） were sol-gel coated on the surface roughened Ti6AI4V alloy by dip coating method for biomedical applications. The Ta-TiO2 films on 1.5 mol/L NaOH-HCI pretreated substrate are adherent, but there are cracks for the sample with 33% Ta. X-ray photoelectron spectroscopy results show that Ti and Ta exist as TiP2 and Ta205 in the film, and A1 element is not detectable. X-ray diffraction and Raman scattering analyses reveal that the addition of Ta decreases crystallization of the films. Potentiodynamic polarization test in a Ca-free Hank＇s balanced solution demonstrates that the coating samples markedly improve the corrosion resistance compared with the polished sample. The addition of Ta impedes UV light-induced hydrophilic conversion of the coating samples. The sample with 20% Ta has enough film integrity and hydrophilic conversion rate, and is expected to possess good biological properties.
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Natural Science Foundation of Hubei Province, China (No. 98J029)
文摘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.
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.
文摘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.
基金This work was supported by the National Natural Science Foundation of China(No.50081001)the Education Department Project of Liaoning Province(No.202073425).
文摘In order to improve the corrosion resistance and biocompatibility of NiTi surgical alloy, TiO2 and TiO2-SiO2 thin films were prepared by sol-gel method. The surface characteristics of the film, which include surface composition, microstructure and surface morphology, were studied by X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectra (XPS), respectively. A scratching test was used to assess the interface adhesive strength between the film and substrate. The corrosion resistance of NiTi alloy coated with oxide films were studied by anodic polarization curves measurement in biological solution. Additionally, a preliminary study of the in vitro bioactivity of the films was conducted. The results indicated that TiO2 and TiO2-SiO2 (Ti/Si=4:1) films have higher electrochemical corrosion resistance and can be used as protective layers on NiTi alloy. In addition, TiO2-SiO2 composite films have better bioactivity than TiO2 film.
文摘Gold nanoparticles dispersed Y2O3 films were prepared through a sol-gel method by using yttrium acetate and Au nanoparticles colloid as precursors. The films were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and UV-VIS absorption spectra. XRD patterns and TEM images of Y2O3 ＋ Au films give the same resuits on structure and particle size as that of pure Y2O3 films. The surface plasma resonance （SPR） of Au nanoparticles in Y2O3 ＋ Au film was observed around 550 nm in the absorption spectrum and its position shifts to red with increasing annealing temperature is caused by the increase of dielectric constant of Y2O3 matrix and the size of Au nanoparticles. The second and third order nonlinear optical effects of Y2O3 ＋ Au films were also observed. The photoluminescent properties of Y2O3 ： Eu ＋ Au films were investigated and results indicate that there exist an energy transfer from Eu^3 ＋ to Au nanoparticles and this energy transfer decreases the emission of Eu^3 ＋ in Y2O3 ： Eu ＋ Au film.
基金The work was partially supported by a grant from the National Natural Science Foundation of China and the ResearchGrants Counc
文摘Porous TiO2 thin films were prepared from alkoxide solutions with and without polyethylene glycol (PEG) by sol-get route on soda lime glass, and were characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that TiO2 film prepared from precursor solution without PEG is composed of spherical particles of about 100 nm and several nanometer mesoporous pores. With the increase of the amount of PEG added to the precursor solution, the diameter and the depth of the pores in the resultant films increas on the decomposition of PEG during heat-treatment, which lead to them increase of the surface roughness of the films. XRD and TEM results show that the single anatase phase is precipitated and there are some orientation effects in (101) direction.
文摘In this study, vanadium doped TiO2 thin films were deposited on glass substrates using a sol-gel dip-coating process. X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-Vis spectrophotometer were used to characterize the structural, chemical and the optical properties of the thin films. The photo-catalytic activities of films were investigated by methylene blue degradation. Water contact angle on the film surfaces was measured by a water contact angle analyzer. The results indicated that vanadium doping had a significant effect on the self-cleaning properties of TiO2 thin films.
基金the National"973"Plan Research Project(No.2004CB619204)Educational Ministry Scientific and Technological Research Key Project(No.02052)
文摘Pure TiO2 thin films and iron doped TiO2 thin films on glass substrate were prepared by sol-gel method, and characterized by X-ray diffractometer （XRD）, thermo-gravimetric analysis （TG-DSC）, high resolution transmission electron microscope （HRTEM）, scanning electron microscope （SEM） and UV-Vis spectroscopy, respectively. The experimental results show that the pure TiO2 thin films and iron doped TiO2 thin films can destroy most of the escherichia coli and bacillus subtillis under the irradiation of 365 nm UV-light. However, the iron doped TiO2 thin film is a better photocatalyst than pure TiO2 thin film. The ultrastructural studies provide direct evidences for understanding the bactericidal mechanism of the TiO2 photocatalyst.
文摘Delafossite structured p-type wide bandgap semiconductor, CuYO<sub>2</sub> thin films were prepared on SiO<sub>2</sub> substrate by sol-gel method using copper (II) acetate and yttrium (III) acetate as source materials. The films preparation process was studied by varying annealing temperature after the preparation of gel films by spin coating, followed by thermal annealing at higher temperature. In the present work, one step annealing directly from Cu-Y-gel under nitrogen flow was used. X-ray diffraction (XRD) revealed that the film annealed at 800<sup>。</sup>C is significantly c-axis oriented, shows only (002) and (004) peaks at 15.6<sup>。</sup> and 31.5<sup>。</sup>, respectively. The optical bandgap of 3.7 - 3.8 eV is estimated by (αhν)2 plot which is higher than previous works. In addition, the films with highly c-axis orientation showed photoluminescence (PL) at room temperature with very broad peak at 2.3 eV. The films annealed at different temperature showed different structural properties.
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supported by the grants from the Nature Science Foundation of Zhejiang Province (Y406309)Research Program from Science and Technology Bureau of Jinhua City (2008-1-151)
文摘Y2O3：Er^3＋ films were prepared by a simple sol-gel process. The structural properties of Y2O3：Er^3＋ films were characterized with X-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The results indicated that the Y2O3：Er^3＋ films might have high upconversion efficiency because of their low vibrational energy. Under 785 and 980 nm laser excitation, the samples showed green （^2H11/2→^4I15/2, ^4S3/2→^4I15/2） and red （^4F9/2→^4I15/2） upconversion emissions. The upconversion mechanisms were studied in detail through laser power dependence. Excited state absorption and energy transfer process were discussed as possible upconversion mechanisms. The cross relaxation process in Er^3＋ was also investigated.
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.
基金We are very grateful to the National Natural Science of Foundation of China(No.69978017,59802007)Shanghai Education Committee(No JW99-TJ-03)for their help and financial supports
文摘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.
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.
