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
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
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
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
Preparation of TiO<sub>2</sub> thin films by MOCVD method is presented in this paper. A MOCVD system has been designed and built. A wide range of processing conditions are investigated to deposit TiO<su...Preparation of TiO<sub>2</sub> thin films by MOCVD method is presented in this paper. A MOCVD system has been designed and built. A wide range of processing conditions are investigated to deposit TiO<sub>2</sub> films on Si wafers starting from metal-organic precursor tetrabutyl titanate. Activation energy of the film formation （E） is obtained to be 23.6 kJ/mol. Structure of films is pure anatase when deposit temperatures are low, rutile forms at 700℃. The films also exhibit preferred crystallographic orientations which strongly depend on deposit conditions. Refractive index increases with increasing of film thickness and decreasing of deposit temperature.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
TiO2 is a promising photocatalyst. However, the low photocatalytic efficiency calls for the modification of TiO2. Metal- and nonmetal-doping of TiO2 have been proved to be effective ways to enhance photocatalytic prop...TiO2 is a promising photocatalyst. However, the low photocatalytic efficiency calls for the modification of TiO2. Metal- and nonmetal-doping of TiO2 have been proved to be effective ways to enhance photocatalytic properties. This review provides a deep insight into the understanding of the metal- and nonmetal-doped TiO2 photocatalysts. This article begins with the introduction of the crystal structures of TiO2 and applications of TiO2 materials. We then reviewed the doped-TiO2 system in two categories： （1） metal-doped TiO2 photocatalysts system, and （2） nonmetal-doped TiO2 photocatalysts system. Both experimental results and theoretical analyses are elaborated in this section. In the following part, for the advantages of TiO2 thin films over particles, various preparation methods to obtain TiO2 thin films are briefly discussed. Finally, this review ends with a concise conclusion and outlook of new trends in the development of TiO2-based photocatalysts.展开更多
TiO2 thin films were prepared by DC magnetron sputtering with the oxygen flow rate higher than the threshold. The film deposited for 5 h was of anatase phase with a preferred orientation along the <220> directio...TiO2 thin films were prepared by DC magnetron sputtering with the oxygen flow rate higher than the threshold. The film deposited for 5 h was of anatase phase with a preferred orientation along the <220> direction, but the films deposited for 2 and 3 h were amorphous. The transmittance and photocatalytic activity of the TiO2 films increased constantly with increasing film thickness. When the annealing temperature was lower than 700℃, only anatase grew in the TiO2 film. TiO2 phase changed from anatase to rutile when the annealing temperature was above 800℃. The photocatalytic activity decreased with increasing annealing temperature.展开更多
The transparent C-doped TiO2 nanostructure films were fabricated on the silicate glass substrates by sol-gel spin-coated method. The as-prepared films were characterized by X-ray diffraction （XRD）, scanning electron...The transparent C-doped TiO2 nanostructure films were fabricated on the silicate glass substrates by sol-gel spin-coated method. The as-prepared films were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, UV-visible absorption spectra （UV-vis） and X-ray photoelectron spectroscopy （XPS）. The photocatalytic activity was evaluated via the photocatalytic oxidation of methylene blue in aqueous under daylight irradiation at room temperature. The results show that the daylight-induced photocatalytic activities of the as-prepared films are improved by the C-doping. The calcination temperatures significantly affect the morphology, microstructure and photocatalytic activity of the as-prepared samples. At 723 K, the C-doped TiO2 films exhibit the highest photocatalytic activity due to the synergetic effects of good crystallization, appropriate oxygen vacancies and strong absorption in the near UV and visible-light region.展开更多
The waterborne polyurethane/doped Ti O2 nanoparticle hybrid films were prepared. Nd, I doped Ti O2 was prepared with a 50 nm particle size firstly. The hybrid film was prepared by mixing doped Ti O2 with waterborne po...The waterborne polyurethane/doped Ti O2 nanoparticle hybrid films were prepared. Nd, I doped Ti O2 was prepared with a 50 nm particle size firstly. The hybrid film was prepared by mixing doped Ti O2 with waterborne polyurethane, followed by heat treatment. The presence and nanometric distribution of doped Ti O2 nanoparticles in prepared membranes is evident according to SEM images. The photocatalytic activities of doped Ti O2 were signifi cantly enhanced compared with pure Ti O2 powders. After the hybrid fi lm fabrication, the photocatalytic activities were almost the same as the pure catalysts with kMB of 0.046. In the antibacterial testing, the hybrid fi lms can inhibit E. coli growth. A signifi cant decrease in membrane fl uidity and increase of permeability of E. coli were observed.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
To deposit TiO2 films through plasma CVD, the partial pressure ratio of O2 to TIC14 should be greater than the stoichiometric ratio （PO2/PTiCl4 〉 1）. However, this may lead to the formation of powder instead of fil...To deposit TiO2 films through plasma CVD, the partial pressure ratio of O2 to TIC14 should be greater than the stoichiometric ratio （PO2/PTiCl4 〉 1）. However, this may lead to the formation of powder instead of film on the substrate when using volume dielectric barrier discharge （volume-DBD） at atmospheric pressure. In this study, by adding N2 into the working gas Ar, TiO2 photocatalytic films were successfully fabricated in the presence of excess O2 （PO2/PTiC14 = 2.6） by using a wire-to-plate atmospheric-pressure volume-DBD. The tuning effect of N2 on the deposition of TiO2 film was studied in detail. The results showed that by increasing the N2 content, the deposition rate and particle size of the TiO2 film were reduced, and its photocatalytic activity was enhanced. The tuning mechanism of N2 is further discussed.展开更多
Thin nanocrystalline TiO2 films doped by europium ions (Eu3+) were obtained by the sol-gel method. The photoelectric properties of Eu3+-doped TiO2 film electrode sensitized by cis-RuL2(SCN)2·2H2O (L=cis-2,2′-bip...Thin nanocrystalline TiO2 films doped by europium ions (Eu3+) were obtained by the sol-gel method. The photoelectric properties of Eu3+-doped TiO2 film electrode sensitized by cis-RuL2(SCN)2·2H2O (L=cis-2,2′-bipyridine-4,4′-dicarboxlic acid) ruthenium complex were studied. The thin films were characterized by X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy. Effect of doping Eu3+ on microscopic structure and photoelectrical properties were discussed. The result shows that doping europium ions makes specific surface area of these films larger, which contributes to improving the photoelectric properties. It is found that an optimal composition doped with 0.2 mol.% Eu3+ exhibits the highest photoelectric properties. Isc is 0.37 mA·cm-2, which is 0.17 mA·cm-2 bigger than that of un-doped films; Voc is 405 mV, which is 50 mV bigger than that of un-doped films.展开更多
The nano-ZnFe2O4/TiO2 films possess the functions of desulfurization and degradation for organic pollutants. The sols of ZnFe2O4/TiO2 were prepared by sol-gel method and coated on glass and porous ceramic by vertical ...The nano-ZnFe2O4/TiO2 films possess the functions of desulfurization and degradation for organic pollutants. The sols of ZnFe2O4/TiO2 were prepared by sol-gel method and coated on glass and porous ceramic by vertical coating and dipping-lift processes, respectively, and the samples were obtained after drying and sintering. The composition, appearance, absorption spectrum of the films, and the influence of the film on porous ceramic performances were analyzed using SEM, AFM, UVVis spectrometer, and mercury porosimeter, respectively, to determine the operation parameters of the multifunction porous ceramic elements for gas-purification.展开更多
This paper reported that the Mn-doped TiO2 films were prepared by radio frequency （RF） magnetron cosputtering. X-ray diffraction measurements indicate that the samples are easy to form the futile structure, and the ...This paper reported that the Mn-doped TiO2 films were prepared by radio frequency （RF） magnetron cosputtering. X-ray diffraction measurements indicate that the samples are easy to form the futile structure, and the sizes of the crystal grains grow big and big as the Mn concentration increases. X-ray photoemlssion spectroscopy measurements and high resolution transmission electron microscope photographs confirm that the manganese ions have been effectively doped into the TiO2 crystal when the Mn concentration is lower than 21%. The magnetic property measurements show that the Ti1-xMnxO2 （x = 0.21） films are ferromagnetic at room temperature, and the saturation magnetization, coercivity, and saturation field are 16.0 emu/cm^3, 167.5 × 80 A/m and 3740 × 80 A/m at room temperature, respectively. The room-temperature ferromagnetism of the films can be attributed to the new futile Ti1-xMnxO2 structure formed by the substitution of Mn^4＋ for Ti^4＋ into the TiO2 crystal .lattice, and could be explained by O vacancy （Vo）-enhanced ferromagnetism model.展开更多
Although scaling will continue for couple of decades but device geometries reaches to atomic size and limitation of quantum mechanical physical boundaries. To address these problems there is need of innovation in mate...Although scaling will continue for couple of decades but device geometries reaches to atomic size and limitation of quantum mechanical physical boundaries. To address these problems there is need of innovation in material science & engineering, device structure, and new nano devices based on different principle of physics. So TiO2 thin films have been grown on well clean N-type silicon substrates via a sol–gel spin coating method. MOS capacitor were fabricated and characterized with SiO2 and TiO2 as dielectric material on N-type silicon wafer. The thickness was measured by stylus profiler and found to be 510 ? and 528 ? for SiO2 and TiO2 respectively. Some of the material parameters were found from the measured Capacitance -Voltage (C-V) curve obtained by SUPREM-III (Stanford University Process Engineering Model Version 0-83) for SiO2 and C-V Keithly 590 analyzer for TiO2 thin films. The result shows that obtained TiO2 film present a dielectric constant of approximately 80. The refractive index was found to be 2.4 and optical constant was 5.43 obtained from Ellipsometry. Band gap 3.6 eV of TiO2 was calculated by spectrophotometer and Surface morphology was obtained using Scanning Electron Microscope (SEM-JEOL) micrograph. The aluminum (Al) metal was deposited by the thermal evaporation system on the back side of the sample for the ohmic contact. Analysis shows that TiO2 may be acceptable as a viable substitute for high k dielectric in order to prevent the tunneling current problems.展开更多
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.
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Preparation of TiO<sub>2</sub> thin films by MOCVD method is presented in this paper. A MOCVD system has been designed and built. A wide range of processing conditions are investigated to deposit TiO<sub>2</sub> films on Si wafers starting from metal-organic precursor tetrabutyl titanate. Activation energy of the film formation （E） is obtained to be 23.6 kJ/mol. Structure of films is pure anatase when deposit temperatures are low, rutile forms at 700℃. The films also exhibit preferred crystallographic orientations which strongly depend on deposit conditions. Refractive index increases with increasing of film thickness and decreasing of deposit temperature.
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.
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TiO2 is a promising photocatalyst. However, the low photocatalytic efficiency calls for the modification of TiO2. Metal- and nonmetal-doping of TiO2 have been proved to be effective ways to enhance photocatalytic properties. This review provides a deep insight into the understanding of the metal- and nonmetal-doped TiO2 photocatalysts. This article begins with the introduction of the crystal structures of TiO2 and applications of TiO2 materials. We then reviewed the doped-TiO2 system in two categories： （1） metal-doped TiO2 photocatalysts system, and （2） nonmetal-doped TiO2 photocatalysts system. Both experimental results and theoretical analyses are elaborated in this section. In the following part, for the advantages of TiO2 thin films over particles, various preparation methods to obtain TiO2 thin films are briefly discussed. Finally, this review ends with a concise conclusion and outlook of new trends in the development of TiO2-based photocatalysts.
基金supported by the National Natural Science Foundation of China(No.50001013)Hundred-Talent Project of CAS and the NSFC for Outstanding Young Scientists(No.59625103).
文摘TiO2 thin films were prepared by DC magnetron sputtering with the oxygen flow rate higher than the threshold. The film deposited for 5 h was of anatase phase with a preferred orientation along the <220> direction, but the films deposited for 2 and 3 h were amorphous. The transmittance and photocatalytic activity of the TiO2 films increased constantly with increasing film thickness. When the annealing temperature was lower than 700℃, only anatase grew in the TiO2 film. TiO2 phase changed from anatase to rutile when the annealing temperature was above 800℃. The photocatalytic activity decreased with increasing annealing temperature.
基金Funded by Shan Xi Research Fund for Returned Scholars (No.2007-25)Shan Xi Open Fund for Key Laboratory(No.2008012013-7)The Specialized Fund for The Innovative of College Students of Tai Yuan City(No.09122018)
文摘The transparent C-doped TiO2 nanostructure films were fabricated on the silicate glass substrates by sol-gel spin-coated method. The as-prepared films were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, UV-visible absorption spectra （UV-vis） and X-ray photoelectron spectroscopy （XPS）. The photocatalytic activity was evaluated via the photocatalytic oxidation of methylene blue in aqueous under daylight irradiation at room temperature. The results show that the daylight-induced photocatalytic activities of the as-prepared films are improved by the C-doping. The calcination temperatures significantly affect the morphology, microstructure and photocatalytic activity of the as-prepared samples. At 723 K, the C-doped TiO2 films exhibit the highest photocatalytic activity due to the synergetic effects of good crystallization, appropriate oxygen vacancies and strong absorption in the near UV and visible-light region.
基金Funded by the National Natural Science Foundation of China(No.51208141)Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.QA201206)
文摘The waterborne polyurethane/doped Ti O2 nanoparticle hybrid films were prepared. Nd, I doped Ti O2 was prepared with a 50 nm particle size firstly. The hybrid film was prepared by mixing doped Ti O2 with waterborne polyurethane, followed by heat treatment. The presence and nanometric distribution of doped Ti O2 nanoparticles in prepared membranes is evident according to SEM images. The photocatalytic activities of doped Ti O2 were signifi cantly enhanced compared with pure Ti O2 powders. After the hybrid fi lm fabrication, the photocatalytic activities were almost the same as the pure catalysts with kMB of 0.046. In the antibacterial testing, the hybrid fi lms can inhibit E. coli growth. A signifi cant decrease in membrane fl uidity and increase of permeability of E. coli were observed.
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.
基金supported by National Natural Science Foundation of China(Nos.10835004,51077009)the Fundamental Research Funds for the Central Universities
文摘To deposit TiO2 films through plasma CVD, the partial pressure ratio of O2 to TIC14 should be greater than the stoichiometric ratio （PO2/PTiCl4 〉 1）. However, this may lead to the formation of powder instead of film on the substrate when using volume dielectric barrier discharge （volume-DBD） at atmospheric pressure. In this study, by adding N2 into the working gas Ar, TiO2 photocatalytic films were successfully fabricated in the presence of excess O2 （PO2/PTiC14 = 2.6） by using a wire-to-plate atmospheric-pressure volume-DBD. The tuning effect of N2 on the deposition of TiO2 film was studied in detail. The results showed that by increasing the N2 content, the deposition rate and particle size of the TiO2 film were reduced, and its photocatalytic activity was enhanced. The tuning mechanism of N2 is further discussed.
文摘Thin nanocrystalline TiO2 films doped by europium ions (Eu3+) were obtained by the sol-gel method. The photoelectric properties of Eu3+-doped TiO2 film electrode sensitized by cis-RuL2(SCN)2·2H2O (L=cis-2,2′-bipyridine-4,4′-dicarboxlic acid) ruthenium complex were studied. The thin films were characterized by X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy. Effect of doping Eu3+ on microscopic structure and photoelectrical properties were discussed. The result shows that doping europium ions makes specific surface area of these films larger, which contributes to improving the photoelectric properties. It is found that an optimal composition doped with 0.2 mol.% Eu3+ exhibits the highest photoelectric properties. Isc is 0.37 mA·cm-2, which is 0.17 mA·cm-2 bigger than that of un-doped films; Voc is 405 mV, which is 50 mV bigger than that of un-doped films.
基金Supported by National 863 Project of China (2001AAA333040).
文摘The nano-ZnFe2O4/TiO2 films possess the functions of desulfurization and degradation for organic pollutants. The sols of ZnFe2O4/TiO2 were prepared by sol-gel method and coated on glass and porous ceramic by vertical coating and dipping-lift processes, respectively, and the samples were obtained after drying and sintering. The composition, appearance, absorption spectrum of the films, and the influence of the film on porous ceramic performances were analyzed using SEM, AFM, UVVis spectrometer, and mercury porosimeter, respectively, to determine the operation parameters of the multifunction porous ceramic elements for gas-purification.
基金Project supported by the Aeronautical Science foundation of China (Grant No 2003ZG51069)the National Defence BaseResearch of China
文摘This paper reported that the Mn-doped TiO2 films were prepared by radio frequency （RF） magnetron cosputtering. X-ray diffraction measurements indicate that the samples are easy to form the futile structure, and the sizes of the crystal grains grow big and big as the Mn concentration increases. X-ray photoemlssion spectroscopy measurements and high resolution transmission electron microscope photographs confirm that the manganese ions have been effectively doped into the TiO2 crystal when the Mn concentration is lower than 21%. The magnetic property measurements show that the Ti1-xMnxO2 （x = 0.21） films are ferromagnetic at room temperature, and the saturation magnetization, coercivity, and saturation field are 16.0 emu/cm^3, 167.5 × 80 A/m and 3740 × 80 A/m at room temperature, respectively. The room-temperature ferromagnetism of the films can be attributed to the new futile Ti1-xMnxO2 structure formed by the substitution of Mn^4＋ for Ti^4＋ into the TiO2 crystal .lattice, and could be explained by O vacancy （Vo）-enhanced ferromagnetism model.
文摘Although scaling will continue for couple of decades but device geometries reaches to atomic size and limitation of quantum mechanical physical boundaries. To address these problems there is need of innovation in material science & engineering, device structure, and new nano devices based on different principle of physics. So TiO2 thin films have been grown on well clean N-type silicon substrates via a sol–gel spin coating method. MOS capacitor were fabricated and characterized with SiO2 and TiO2 as dielectric material on N-type silicon wafer. The thickness was measured by stylus profiler and found to be 510 ? and 528 ? for SiO2 and TiO2 respectively. Some of the material parameters were found from the measured Capacitance -Voltage (C-V) curve obtained by SUPREM-III (Stanford University Process Engineering Model Version 0-83) for SiO2 and C-V Keithly 590 analyzer for TiO2 thin films. The result shows that obtained TiO2 film present a dielectric constant of approximately 80. The refractive index was found to be 2.4 and optical constant was 5.43 obtained from Ellipsometry. Band gap 3.6 eV of TiO2 was calculated by spectrophotometer and Surface morphology was obtained using Scanning Electron Microscope (SEM-JEOL) micrograph. The aluminum (Al) metal was deposited by the thermal evaporation system on the back side of the sample for the ohmic contact. Analysis shows that TiO2 may be acceptable as a viable substitute for high k dielectric in order to prevent the tunneling current problems.
