Two kinds of TiO_2 nanometer thin films were prepared on stainless steel bythe reverse micellar and sol-gel methods, respectively. The calcined TiO_ 2 thin films werecharacterized by X-ray diffraction (XRD), atomic fo...Two kinds of TiO_2 nanometer thin films were prepared on stainless steel bythe reverse micellar and sol-gel methods, respectively. The calcined TiO_ 2 thin films werecharacterized by X-ray diffraction (XRD), atomic force microscopy (AFM), BET surface area and X-rayphotoelectron spectroscopy (XPS). Photocatalytic activity was evaluated by photocatalyticdecoloration of methyl orange aqueous solution. The results showed that the TiO_2 thin filmsprepared by reverse micellar method (designated as RM-TiO_2 films) showed higher photocatalyticactivity than those by sol-gel method (designated as SG-TiO_2 films). This is attributed to the factthat the former is composed of smaller monodispersed spherical particles with a size of about 15 nmand possesses higher surface areas.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
The influence of amorphous TiO_2 seeding layers on the phase composition of lead magnesium niobate-lead titanate(0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3,PMN-PT) films deposited on Pt/Ti/SiO2/Si substrate by RF magnetron sputter...The influence of amorphous TiO_2 seeding layers on the phase composition of lead magnesium niobate-lead titanate(0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3,PMN-PT) films deposited on Pt/Ti/SiO2/Si substrate by RF magnetron sputtering was examined.The relation between seeding layer thickness and phase composition at different post annealing temperature was observed by XRD.The thickness of amorphous TiO2 seeding layer and post annealing temperature had remarkable effects on PMN-PT film phase composition.When amorphous seeding layer becomes thick,a new phase of Nb2O5 exists in the films.Only when the seeding layer thickness is suitable,the film with pure perovskite phase can be attained.展开更多
The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces, and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were investigated. The influence...The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces, and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were investigated. The influence of the application conditions of dye adsorbed on TiO2 films on the amount of dye adsorption was discussed. Experimental results show that the concentration, the temperature of dye solutions and the dipping time of TiO2 films in the dye solutions have a significant influence on the amount of dye adsorption. Cell test indicates that the conversion efficiency of light to electricity increases with the amount of dye adsorption.展开更多
It is well known that the photocatalytic activity of TiO_2 thin filmsstrongly depends on the preparing methods and post-treatment conditions, since they have a decisiveinfluence on the chemical and physical properties...It is well known that the photocatalytic activity of TiO_2 thin filmsstrongly depends on the preparing methods and post-treatment conditions, since they have a decisiveinfluence on the chemical and physical properties of TiO_2 thin films. Therefore, it is necessary toelucidate the influence of the preparation process and post-treatment conditions on thephoto-catalytic activity and surface microstructures of the films. This review deals with thepreparation of TiO_2 thin film photo-catalysts by wet-chemical methods (such as sol-gel,-reversemicellar and liquid phase deposition) and the comparison of various preparation methods as well astheir advantage and disadvantage. Furthermore, it is discussed that the advancement ofphotocatalytic activity, super-hydrophilicity and bactericidal activity of TiO_2 thin filmphotocatalyst in recent years.展开更多
The nanometer and ordinary anatase titanium dioxide(TiO_2) powders were adopted as the sonocatalysts for the degradation of methyl orange used as a model compound for the first time. It was found that the sonocatalyti...The nanometer and ordinary anatase titanium dioxide(TiO_2) powders were adopted as the sonocatalysts for the degradation of methyl orange used as a model compound for the first time. It was found that the sonocatalytic degradation effect of methyl orange in the presence of TiO_2 powder were much better than that without TiO_2, but the sonocatalytic activity of the nanometer anatase TiO_2 particle was obviously higher than that of ordinary anatase TiO_2 particle. Although there are many factors influencing sonocatalytic degradation of methyl orange, the experimental results showed that the best degradation ratio of methyl orange could be obtained when the experimental conditions were: initial concentration 15 mg/L, nanometer anatase TiO_2 adding amount 750 mg/L, ultrasonic frequency 40 kHz, output power 50 W, pH = 3.0 and temperature 40℃ within 150 min. In addition, the catalytic activity of reused nanometer anatase TiO_2 catalyst was also studied and found to decline gradually comparing with initial nanometer anatase TiO_2 catalyst. All experiments indicated that the method of the sonocatalytic degradation of organic pollutants in the presence of TiO_2 powder was an advisable choice for non- or low-transparent organic wastewaters.展开更多
Crystalline TiO2 thin films were prepared by DC reactive magnetron sputtering on indium-tin oxide（ITO） thin film deposited on quartz substrate, the photoconductive UV detector on TiO2 thin films was based on a sandw...Crystalline TiO2 thin films were prepared by DC reactive magnetron sputtering on indium-tin oxide（ITO） thin film deposited on quartz substrate, the photoconductive UV detector on TiO2 thin films was based on a sandwich structure of C/ TiO2/ITO. The measurement of the I-V characteristics for these devices shows good ohmic contact. The photoresponse of TiO2 thin films was analyzed at different bias voltage. The detector shows a good photoresponse with a rise time of 2 s and a fall time of 40 s, the photocurrent is linearly increased with the bias voltage.展开更多
The performance of pearlescent pigment significantly affected by the grain size and the roughness of deposited film. The effect of TiCl_(4) concentration on the initial deposition of TiO_(2) on mica by atmospheric pre...The performance of pearlescent pigment significantly affected by the grain size and the roughness of deposited film. The effect of TiCl_(4) concentration on the initial deposition of TiO_(2) on mica by atmospheric pressure chemical vapor deposition(APCVD) was investigated. The precursor concentration significantly affected the deposition and morphology of TiO_(2) grains assembling the film. The deposition time for fully covering the surface of mica decreased from 120 to 10 s as the TiCl_(4) concentration increased from 0.38%to 2.44%. The grain size increased with the TiCl_(4) concentration. The AFM and TEM analysis demonstrated that the aggregation of TiO_(2) clusters at the initial stage finally result to the agglomeration of fine TiO_(2) grains at high TiCl_(4) concentrations. Following the results, it was suggested that the nucleation density and size was easy to be adjusted when the TiCl_(4) concentration is below 0.90%.展开更多
TiO2 thin films were prepared on glass substrates using the PLD (Pulsed Laser Deposition) technique. In order to carry out the ablation process, a Nd:YAG laser was used emitting in 1064 nm wavelength at 10 Hz repetiti...TiO2 thin films were prepared on glass substrates using the PLD (Pulsed Laser Deposition) technique. In order to carry out the ablation process, a Nd:YAG laser was used emitting in 1064 nm wavelength at 10 Hz repetition rate, set up for operating in both single-pulse and multi-pulse regimes. A comparison of the deposition rate, the optical and morphological properties of the layers obtained from both ablation regimes was made, which showed that the multi-pulsed ablation produced layers with a higher surface quality and better optical properties.展开更多
The effects of radio frequency(RF)atmospheric pressure(AP)He/H_(2)plasma and thermal treatment on the hydrogenation of TiO_(2)thin films were investigated and compared in this work.The color of the original TiO_(2)fil...The effects of radio frequency(RF)atmospheric pressure(AP)He/H_(2)plasma and thermal treatment on the hydrogenation of TiO_(2)thin films were investigated and compared in this work.The color of the original TiO_(2)film changes from white to black after being hydrogenated in He/H_(2)plasma at160 W(gas temperature~381℃)within 5 min,while the color of the thermally treated TiO_(2)film did not change significantly even in pure H_(2)or He/H_(2)atmosphere with higher temperature(470℃)and longer time(30 min).This indicated that a more effective hydrogenation reaction happened through RF AP He/H_(2)plasma treatment than through pure H_(2)or He/H_(2)thermal treatment.The color change of TiO_(2)film was measured based on the Commission Internationale d’Eclairage L*a*b*color space system.Hydrogenated TiO_(2)film displayed improved visible light absorption with increased plasma power.The morphology of the cauliflower-like nanoparticles of the TiO_(2)film surface remained unchanged after plasma processing.X-ray photoelectron spectroscopy results showed that the contents of Ti3+species and Ti-OH bonds in the plasma-hydrogenated black TiO_(2)increased compared with those in the thermally treated TiO_(2).X-ray diffraction(XRD)patterns and Raman spectra indicated that plasma would destroy the crystal structure of the TiO_(2)surface layer,while thermal annealing would increase the overall crystallinity.The different trends of XRD and Raman spectra results suggested that plasma modification on the TiO_(2)surface layer is more drastic than on its inner layer,which was also consistent with transmission electron microscopy results.Optical emission spectra results suggest that numerous active species were generated during RF AP He/H_(2)plasma processing,while there were no peaks detected from thermal processing.A possible mechanism for the TiO_(2)hydrogenation process by plasma has been proposed.Numerous active species were generated in the bulk plasma region,accelerated in the sheath region,and bumped toward the TiO_(2)film,which will react with the TiO_(2)surface to form OVs and disordered layers.This leads to the tailoring of the band gap of black TiO_(2)and causes its light absorption to extend into the visible region.展开更多
基金This project is financially supported by the National Natural Science Foundation of China (No.s 50272049, 50072016) The Excellent Young Teachers Program of MOE, China (No. (2002)350)
文摘Two kinds of TiO_2 nanometer thin films were prepared on stainless steel bythe reverse micellar and sol-gel methods, respectively. The calcined TiO_ 2 thin films werecharacterized by X-ray diffraction (XRD), atomic force microscopy (AFM), BET surface area and X-rayphotoelectron spectroscopy (XPS). Photocatalytic activity was evaluated by photocatalyticdecoloration of methyl orange aqueous solution. The results showed that the TiO_2 thin filmsprepared by reverse micellar method (designated as RM-TiO_2 films) showed higher photocatalyticactivity than those by sol-gel method (designated as SG-TiO_2 films). This is attributed to the factthat the former is composed of smaller monodispersed spherical particles with a size of about 15 nmand possesses higher surface areas.
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.
文摘The influence of amorphous TiO_2 seeding layers on the phase composition of lead magnesium niobate-lead titanate(0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3,PMN-PT) films deposited on Pt/Ti/SiO2/Si substrate by RF magnetron sputtering was examined.The relation between seeding layer thickness and phase composition at different post annealing temperature was observed by XRD.The thickness of amorphous TiO2 seeding layer and post annealing temperature had remarkable effects on PMN-PT film phase composition.When amorphous seeding layer becomes thick,a new phase of Nb2O5 exists in the films.Only when the seeding layer thickness is suitable,the film with pure perovskite phase can be attained.
基金This work was supported by the National Key Project of China for Basic Research on Photovoltaic cell No.2000028200 and the CAS Knowledge Innovation Project No.KGCX2-303
文摘The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces, and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were investigated. The influence of the application conditions of dye adsorbed on TiO2 films on the amount of dye adsorption was discussed. Experimental results show that the concentration, the temperature of dye solutions and the dipping time of TiO2 films in the dye solutions have a significant influence on the amount of dye adsorption. Cell test indicates that the conversion efficiency of light to electricity increases with the amount of dye adsorption.
文摘It is well known that the photocatalytic activity of TiO_2 thin filmsstrongly depends on the preparing methods and post-treatment conditions, since they have a decisiveinfluence on the chemical and physical properties of TiO_2 thin films. Therefore, it is necessary toelucidate the influence of the preparation process and post-treatment conditions on thephoto-catalytic activity and surface microstructures of the films. This review deals with thepreparation of TiO_2 thin film photo-catalysts by wet-chemical methods (such as sol-gel,-reversemicellar and liquid phase deposition) and the comparison of various preparation methods as well astheir advantage and disadvantage. Furthermore, it is discussed that the advancement ofphotocatalytic activity, super-hydrophilicity and bactericidal activity of TiO_2 thin filmphotocatalyst in recent years.
基金Foundation item: The National Natural Science Foundation of China(No. 20371023)
文摘The nanometer and ordinary anatase titanium dioxide(TiO_2) powders were adopted as the sonocatalysts for the degradation of methyl orange used as a model compound for the first time. It was found that the sonocatalytic degradation effect of methyl orange in the presence of TiO_2 powder were much better than that without TiO_2, but the sonocatalytic activity of the nanometer anatase TiO_2 particle was obviously higher than that of ordinary anatase TiO_2 particle. Although there are many factors influencing sonocatalytic degradation of methyl orange, the experimental results showed that the best degradation ratio of methyl orange could be obtained when the experimental conditions were: initial concentration 15 mg/L, nanometer anatase TiO_2 adding amount 750 mg/L, ultrasonic frequency 40 kHz, output power 50 W, pH = 3.0 and temperature 40℃ within 150 min. In addition, the catalytic activity of reused nanometer anatase TiO_2 catalyst was also studied and found to decline gradually comparing with initial nanometer anatase TiO_2 catalyst. All experiments indicated that the method of the sonocatalytic degradation of organic pollutants in the presence of TiO_2 powder was an advisable choice for non- or low-transparent organic wastewaters.
文摘Crystalline TiO2 thin films were prepared by DC reactive magnetron sputtering on indium-tin oxide（ITO） thin film deposited on quartz substrate, the photoconductive UV detector on TiO2 thin films was based on a sandwich structure of C/ TiO2/ITO. The measurement of the I-V characteristics for these devices shows good ohmic contact. The photoresponse of TiO2 thin films was analyzed at different bias voltage. The detector shows a good photoresponse with a rise time of 2 s and a fall time of 40 s, the photocurrent is linearly increased with the bias voltage.
基金the support from National Natural Science Foundation of China (22208355, 22178363 and 21978300)the financial support and mica samples from Changzi Wu and RIKA technology CO., LTD.
文摘The performance of pearlescent pigment significantly affected by the grain size and the roughness of deposited film. The effect of TiCl_(4) concentration on the initial deposition of TiO_(2) on mica by atmospheric pressure chemical vapor deposition(APCVD) was investigated. The precursor concentration significantly affected the deposition and morphology of TiO_(2) grains assembling the film. The deposition time for fully covering the surface of mica decreased from 120 to 10 s as the TiCl_(4) concentration increased from 0.38%to 2.44%. The grain size increased with the TiCl_(4) concentration. The AFM and TEM analysis demonstrated that the aggregation of TiO_(2) clusters at the initial stage finally result to the agglomeration of fine TiO_(2) grains at high TiCl_(4) concentrations. Following the results, it was suggested that the nucleation density and size was easy to be adjusted when the TiCl_(4) concentration is below 0.90%.
文摘TiO2 thin films were prepared on glass substrates using the PLD (Pulsed Laser Deposition) technique. In order to carry out the ablation process, a Nd:YAG laser was used emitting in 1064 nm wavelength at 10 Hz repetition rate, set up for operating in both single-pulse and multi-pulse regimes. A comparison of the deposition rate, the optical and morphological properties of the layers obtained from both ablation regimes was made, which showed that the multi-pulsed ablation produced layers with a higher surface quality and better optical properties.
基金financially supported by National Natural Science Foundation of China(Nos.12075054,12205040,12175036,11875104)。
文摘The effects of radio frequency(RF)atmospheric pressure(AP)He/H_(2)plasma and thermal treatment on the hydrogenation of TiO_(2)thin films were investigated and compared in this work.The color of the original TiO_(2)film changes from white to black after being hydrogenated in He/H_(2)plasma at160 W(gas temperature~381℃)within 5 min,while the color of the thermally treated TiO_(2)film did not change significantly even in pure H_(2)or He/H_(2)atmosphere with higher temperature(470℃)and longer time(30 min).This indicated that a more effective hydrogenation reaction happened through RF AP He/H_(2)plasma treatment than through pure H_(2)or He/H_(2)thermal treatment.The color change of TiO_(2)film was measured based on the Commission Internationale d’Eclairage L*a*b*color space system.Hydrogenated TiO_(2)film displayed improved visible light absorption with increased plasma power.The morphology of the cauliflower-like nanoparticles of the TiO_(2)film surface remained unchanged after plasma processing.X-ray photoelectron spectroscopy results showed that the contents of Ti3+species and Ti-OH bonds in the plasma-hydrogenated black TiO_(2)increased compared with those in the thermally treated TiO_(2).X-ray diffraction(XRD)patterns and Raman spectra indicated that plasma would destroy the crystal structure of the TiO_(2)surface layer,while thermal annealing would increase the overall crystallinity.The different trends of XRD and Raman spectra results suggested that plasma modification on the TiO_(2)surface layer is more drastic than on its inner layer,which was also consistent with transmission electron microscopy results.Optical emission spectra results suggest that numerous active species were generated during RF AP He/H_(2)plasma processing,while there were no peaks detected from thermal processing.A possible mechanism for the TiO_(2)hydrogenation process by plasma has been proposed.Numerous active species were generated in the bulk plasma region,accelerated in the sheath region,and bumped toward the TiO_(2)film,which will react with the TiO_(2)surface to form OVs and disordered layers.This leads to the tailoring of the band gap of black TiO_(2)and causes its light absorption to extend into the visible region.
