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
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
TiO2 films have received increasing attention for the removal of organic pollutants via photocatalysis. To develop a simple and effective method for improving the photodegradation efficiency of pollutants in surface w...TiO2 films have received increasing attention for the removal of organic pollutants via photocatalysis. To develop a simple and effective method for improving the photodegradation efficiency of pollutants in surface water, we herein examined the preparation of a P25-TiO2 composite film on a cement substrate via a sol–gel method. In this case, Rhodamine B（Rh B）was employed as the target organic pollutant. The self-generated TiO2 film and the P25-TiO2 composite film were characterized by X-ray diffraction（XRD）, N2 adsorption/desorption measurements, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, and diffuse reflectance spectroscopy（DRS）. The photodegradation efficiencies of the two films were studied by Rh B removal in water under UV（ultraviolet） irradiation. Over 4 day exposure, the P25-TiO2 composite film exhibited higher photocatalytic performance than the self-generated TiO2 film. The photodegradation rate indicated that the efficiency of the P25-TiO2 composite film was enhanced by the addition of the rutile phase Degussa P25 powder. As such, cooperation between the anatase TiO2 and rutile P25 nanoparticles was beneficial for separation of the photo-induced electrons and holes. In addition, the influence of P25 doping on the P25-TiO2 composite films was evaluated. We found that up to a certain saturation point, increased doping enhanced the photodegradation ability of the composite film. Thus, we herein demonstrated that the doping of P25 powders is a simple but effective strategy to prepare a P25-TiO2 composite film on a cement substrate, and the resulting film exhibits excellent removal efficiency in the degradation of organic pollutants.展开更多
High oriented TiO_2-ZrO_2 composite thin films on Si (100) and glass sheet were suc- cessfully prepared by sol-gel process followed by dip-coating the ethanol solution of zirconium oxychloride and titanium tetrachlori...High oriented TiO_2-ZrO_2 composite thin films on Si (100) and glass sheet were suc- cessfully prepared by sol-gel process followed by dip-coating the ethanol solution of zirconium oxychloride and titanium tetrachloride. The sol-gel process, microstructure, morphology and tri- bological properties of TiO_2 -ZrO_2 films were investigated using TGA, DSC, XPS, XRD, AFM and dynamic-static tribometer. The results show that the TiO_2-ZrO_2films are dense, homogeneous and at a complete tetragonal phase with an excellent antiwear and friction reduction performance. Un- der 0.5N applied load, the friction coefficient is 0.14-0.20 and the antiwear life is more than 5000 sliding cycles for both TiO_2-ZrO_2/ AISI 52100 steel and TiO_2-ZrO_2/ Si_3N_4. SEM observation sug- gests that wear mechanism of TiO_2 -ZrO_2 composite film under low load was fatigue wear, and under high load was adhesive wear. The TiO_2 -ZrO_2 films show potential applications as coatings for antiwear and friction reduction under the harsh condition.展开更多
Monolithic TiO 2 aerogels have been prepared from titanium n butoxide by sol gel process and supercritical drying technique, and the structural properties of the aerogel samples have been characterized by means of SEM...Monolithic TiO 2 aerogels have been prepared from titanium n butoxide by sol gel process and supercritical drying technique, and the structural properties of the aerogel samples have been characterized by means of SEM, TEM, XRD, IR, BET and pore distribution analysis. The results indicated that the optimum condition for preparing monolithic TiO 2 aerogels was n [Ti(OC 4H 9) 4]∶ n (C 2H 5OH)∶ n (H 2O)∶ n (HNO 3) =1∶18.3∶3.75∶0.14. The final aerogels which consist of colloidal particles with diameters of about 5 nm were found to be with coherent uniform size and low density solid inorganic materials with porosity of about 90%, and contained mesopore in the range of 10-20 nm. The monolithic TiO 2 aerogels were of the pure amorphous form at room temperature, which would be converted into anatase and then into rutile by increasing the temperature of heat treatment.展开更多
TiO 2 powder, TiO 2/SiO 2 coated particle, and thin film reactor were prepared by sol gel process. Their morphology and structure were characterized by SEM, XRD and IR. Their effects of photocatalytic degradation for ...TiO 2 powder, TiO 2/SiO 2 coated particle, and thin film reactor were prepared by sol gel process. Their morphology and structure were characterized by SEM, XRD and IR. Their effects of photocatalytic degradation for dichlorvos were studied. The Photocatalytic reactivity of thin film TiO 2 are better than that of powder TiO 2.展开更多
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.
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supported by the National Science Funds for Creative Research Groups of China (No. 51421006)the National Major Projects of Water Pollution Control and Management Technology (No. 2017ZX07204003)+2 种基金the National Key Plan for Research and Development of China (2016YFC0502203)the Key Program of National Natural Science Foundation of China (No. 91647206)the Qing Lan Project of Jiangsu Province, and PAPD
文摘TiO2 films have received increasing attention for the removal of organic pollutants via photocatalysis. To develop a simple and effective method for improving the photodegradation efficiency of pollutants in surface water, we herein examined the preparation of a P25-TiO2 composite film on a cement substrate via a sol–gel method. In this case, Rhodamine B（Rh B）was employed as the target organic pollutant. The self-generated TiO2 film and the P25-TiO2 composite film were characterized by X-ray diffraction（XRD）, N2 adsorption/desorption measurements, scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, and diffuse reflectance spectroscopy（DRS）. The photodegradation efficiencies of the two films were studied by Rh B removal in water under UV（ultraviolet） irradiation. Over 4 day exposure, the P25-TiO2 composite film exhibited higher photocatalytic performance than the self-generated TiO2 film. The photodegradation rate indicated that the efficiency of the P25-TiO2 composite film was enhanced by the addition of the rutile phase Degussa P25 powder. As such, cooperation between the anatase TiO2 and rutile P25 nanoparticles was beneficial for separation of the photo-induced electrons and holes. In addition, the influence of P25 doping on the P25-TiO2 composite films was evaluated. We found that up to a certain saturation point, increased doping enhanced the photodegradation ability of the composite film. Thus, we herein demonstrated that the doping of P25 powders is a simple but effective strategy to prepare a P25-TiO2 composite film on a cement substrate, and the resulting film exhibits excellent removal efficiency in the degradation of organic pollutants.
文摘High oriented TiO_2-ZrO_2 composite thin films on Si (100) and glass sheet were suc- cessfully prepared by sol-gel process followed by dip-coating the ethanol solution of zirconium oxychloride and titanium tetrachloride. The sol-gel process, microstructure, morphology and tri- bological properties of TiO_2 -ZrO_2 films were investigated using TGA, DSC, XPS, XRD, AFM and dynamic-static tribometer. The results show that the TiO_2-ZrO_2films are dense, homogeneous and at a complete tetragonal phase with an excellent antiwear and friction reduction performance. Un- der 0.5N applied load, the friction coefficient is 0.14-0.20 and the antiwear life is more than 5000 sliding cycles for both TiO_2-ZrO_2/ AISI 52100 steel and TiO_2-ZrO_2/ Si_3N_4. SEM observation sug- gests that wear mechanism of TiO_2 -ZrO_2 composite film under low load was fatigue wear, and under high load was adhesive wear. The TiO_2 -ZrO_2 films show potential applications as coatings for antiwear and friction reduction under the harsh condition.
文摘Monolithic TiO 2 aerogels have been prepared from titanium n butoxide by sol gel process and supercritical drying technique, and the structural properties of the aerogel samples have been characterized by means of SEM, TEM, XRD, IR, BET and pore distribution analysis. The results indicated that the optimum condition for preparing monolithic TiO 2 aerogels was n [Ti(OC 4H 9) 4]∶ n (C 2H 5OH)∶ n (H 2O)∶ n (HNO 3) =1∶18.3∶3.75∶0.14. The final aerogels which consist of colloidal particles with diameters of about 5 nm were found to be with coherent uniform size and low density solid inorganic materials with porosity of about 90%, and contained mesopore in the range of 10-20 nm. The monolithic TiO 2 aerogels were of the pure amorphous form at room temperature, which would be converted into anatase and then into rutile by increasing the temperature of heat treatment.
文摘TiO 2 powder, TiO 2/SiO 2 coated particle, and thin film reactor were prepared by sol gel process. Their morphology and structure were characterized by SEM, XRD and IR. Their effects of photocatalytic degradation for dichlorvos were studied. The Photocatalytic reactivity of thin film TiO 2 are better than that of powder TiO 2.
