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
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
The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately ...The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.展开更多
TiO_2 sol-gel composite films with dropping molybdenumphosphoric acid(PMoA) have been prepared by sol-gel method.The structure and constitute of composite thin films were studied with Fourier transforms infrared spect...TiO_2 sol-gel composite films with dropping molybdenumphosphoric acid(PMoA) have been prepared by sol-gel method.The structure and constitute of composite thin films were studied with Fourier transforms infrared spectroscopy(FT-IR),atomic force microscopy(AFM),and X-ray diffraction(XRD) patterns,respectively.The photochromic behavior and mechanism of composite thin films were inves-tigated with ultraviolet-visible spectra(UV-vis) and electron spin resonance(ESR).FT-IR results showed that the Keggin geometry of PMoA was still preserved inside PMoA/TiO2 composite thin films,and a charge transfer bridge was built at the interface of PMoA and TiO2 through the Mo-O-Ti bond.Surface topography of the composite film showed obvious changes before/after adding PMoA,and the surface topography of composite films showed obvious changes before/after irradiating as well.Composite thin film had reversible photochromic properties.Irradiated with UV light,transparent films changed from colorless to blue and they can bleach completely with ambient air in the dark.ESR re-sults showed that TiO_2 were excitated by UV light to produce electrons,which deoxidized PMoA to produce heteropolyblues.The photochromic process of PMoA/TiO_2 system was carried through elec-tron transfer mechanism.展开更多
Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire and Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire composite films were successfully prepared using a hydrothermal method.The results show that the light absorption for Bi_(2)WO_(6)/T...Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire and Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire composite films were successfully prepared using a hydrothermal method.The results show that the light absorption for Bi_(2)WO_(6)/TiO_(2) composite films is extended to the visible region after Bi_(2)WO_(6) nanoplates and nanoflowers are assembled onto TiO_(2) nanowires.Furthermore,Bi_(2)WO_(6) nanoflower/TiO_(2) nano wire composite film exhibits a better absorption property compared to Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire film,which is mainly ascribed to the narrower bandgap of Bi_(2)WO_(6) nanoflower compared to that of Bi_(2)WO_(6) nanoplate.The photocurrent density for Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire and Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire composite films can reach 95 and 62.5 μA cm-2,respectively,which are much higher than that obtained for a pure TiO_(2) nanowire film(25 μA cm-2).Meanwhile,under illumination,the pure TiO_(2) nanowire,Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire and Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire films can reduce the potential of the coupled 304 stainless steel in 3.5 wt.%NaCl solution by 299,719 and 739 mV,respectively.Thus,Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire film is found to provide the best effective photocathodic protection for 304 stainless steel.This work not only provides an example of shape-dependent photocathodic protection based on Bi_(2)WO_(6) but also opens up new possibilities to design an ideal microstructure on the basis of semiconductor materials for future applications of photocathodic protection.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.
基金supported by the Natural Science Foundation of Chongqing City(Grant Nos.CSTB2022NSCQ-MSX0751 and cstc2021jcyj-msxmX0500)the Education Department Project of Jilin Province(Grant No.JJKH20220726KJ)+1 种基金the Science and Technology Department Project of Jilin Province(Grant No.20200201077JC)the National Natural Science Foundation of China(Grant No.U2141239).
文摘The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.
文摘TiO_2 sol-gel composite films with dropping molybdenumphosphoric acid(PMoA) have been prepared by sol-gel method.The structure and constitute of composite thin films were studied with Fourier transforms infrared spectroscopy(FT-IR),atomic force microscopy(AFM),and X-ray diffraction(XRD) patterns,respectively.The photochromic behavior and mechanism of composite thin films were inves-tigated with ultraviolet-visible spectra(UV-vis) and electron spin resonance(ESR).FT-IR results showed that the Keggin geometry of PMoA was still preserved inside PMoA/TiO2 composite thin films,and a charge transfer bridge was built at the interface of PMoA and TiO2 through the Mo-O-Ti bond.Surface topography of the composite film showed obvious changes before/after adding PMoA,and the surface topography of composite films showed obvious changes before/after irradiating as well.Composite thin film had reversible photochromic properties.Irradiated with UV light,transparent films changed from colorless to blue and they can bleach completely with ambient air in the dark.ESR re-sults showed that TiO_2 were excitated by UV light to produce electrons,which deoxidized PMoA to produce heteropolyblues.The photochromic process of PMoA/TiO_2 system was carried through elec-tron transfer mechanism.
基金supported by the National Natural Science Foundation of China(Nos.51822402,51671044 and 52001051)the National Key Research and Development Program of China(Nos.2019YFA0209901 and 2018YFA0702901)+4 种基金the fund of the State Key Laboratory of Solidification Processing in NWPU(Grant No.SKLSP201902)the Liao Ning Revitalization Talents Program(XLYC1807047)the National MCF Energy R&D Program(No.2018YFE0312400)the Fund of Science and Technology on Reactor Fuel and Materials Laboratory(STRFML-2020-04)the China Postdoctoral Science Foundation(No.2020M670747).
文摘Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire and Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire composite films were successfully prepared using a hydrothermal method.The results show that the light absorption for Bi_(2)WO_(6)/TiO_(2) composite films is extended to the visible region after Bi_(2)WO_(6) nanoplates and nanoflowers are assembled onto TiO_(2) nanowires.Furthermore,Bi_(2)WO_(6) nanoflower/TiO_(2) nano wire composite film exhibits a better absorption property compared to Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire film,which is mainly ascribed to the narrower bandgap of Bi_(2)WO_(6) nanoflower compared to that of Bi_(2)WO_(6) nanoplate.The photocurrent density for Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire and Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire composite films can reach 95 and 62.5 μA cm-2,respectively,which are much higher than that obtained for a pure TiO_(2) nanowire film(25 μA cm-2).Meanwhile,under illumination,the pure TiO_(2) nanowire,Bi_(2)WO_(6) nanoplate/TiO_(2) nanowire and Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire films can reduce the potential of the coupled 304 stainless steel in 3.5 wt.%NaCl solution by 299,719 and 739 mV,respectively.Thus,Bi_(2)WO_(6) nanoflower/TiO_(2) nanowire film is found to provide the best effective photocathodic protection for 304 stainless steel.This work not only provides an example of shape-dependent photocathodic protection based on Bi_(2)WO_(6) but also opens up new possibilities to design an ideal microstructure on the basis of semiconductor materials for future applications of photocathodic protection.
