ZrO2/TiO2 composite photocatalytic film was produced on the pure titanium substrate using in-situ Zr（OH）4 colloidal particle by the micro-arc oxidation technique and characterized by scanning electron microscope （...ZrO2/TiO2 composite photocatalytic film was produced on the pure titanium substrate using in-situ Zr（OH）4 colloidal particle by the micro-arc oxidation technique and characterized by scanning electron microscope （SEM）, energy dispersive X-ray （EDX）, X-ray diffraction （XRD） and ultraviolet-visible （UV-Vis） spectrophotometer. The composite film shows a lamellar and porous structure which consists of anatase, futile and ZrO2 phases. The optical absorption edge of film is shifted to longer wavelength when ZrO2 is introduced to TiO2. Furthermore, the photocatalytic reaction rate constants of degradation of rhodamine B solution with ZrO2/TiO2 composite film and pure TiO2 film under ultraviolet irradiation are measured as 0.0442 and 0.0186 h 1, respectively.展开更多
Micro-arc oxidation(MAO)is one of the promising methods to improve the corrosion resistance of magnesium alloys.However,there are plenty of micro-pores in the traditional MAO films,deteriorating their protection prope...Micro-arc oxidation(MAO)is one of the promising methods to improve the corrosion resistance of magnesium alloys.However,there are plenty of micro-pores in the traditional MAO films,deteriorating their protection property.A novel self-sealing pore MAO film was developed in this paper.The morphologies and chemical composition of the film were detected by scanning electron microscopy(SEM)and energy dispersive X-ray spectroscopy(EDX).The corrosion behavior was investigated by electrochemical and salt spray tests.The possible film formation and corrosion mechanisms were proposed.The self-sealing pore film presents a blue appearance.Most of the micro-pores in the surface of the film are sealed during the film formation process.The chemical composition of the film mainly contains Mg,O,Ti,F and P.The self-sealing pore film exhibits better corrosion resistance compared with the traditional silicate film.Especially,the self-sealing pore film keeps intact after salt spray test for 2000 h,which can be attributed to its high compactness.展开更多
In-situ pure TiO2 and Fe-doped TiO2 thin films were synthesized on Ti plates via the micro-arc oxidation （MAO） technique. The as-fabricated anatase TiO2 thin film-based conductometric sensors were employed to measur...In-situ pure TiO2 and Fe-doped TiO2 thin films were synthesized on Ti plates via the micro-arc oxidation （MAO） technique. The as-fabricated anatase TiO2 thin film-based conductometric sensors were employed to measure the gas sensitivity to ethanol. The results showed that Fe ions could be easily introduced into the MAO-TiO2 thin films by adding precursor K4（FeCN）6＇3H20 into the NaaPO4 electrolyte. The amount of doped Fe ions increased almost linearly with the concentration of Kg（FeCN）63H20 increasing, eventually affecting the ethanol sensing performances of TiO2 thin films. It was found that the enhanced sensor signals obtained had an optimal concentration of Fe dopant （1.28at%）, by which the maximal gas sensor signal to 1000 ppm ethanol was estimated to be 7.91 at 275℃. The response time was generally reduced by doped Fe ions, which could be ascribed to the increase of oxygen vacancies caused by Fe3＋ substituting for Ti4＋.展开更多
V2Os/TiO2 composite films were prepared on pure titanium substmtes via micro-arc oxidation （MAO） in electrolytes consisting of NaVO3. Their morphology and dements were characterized by scanning electron microscopy ...V2Os/TiO2 composite films were prepared on pure titanium substmtes via micro-arc oxidation （MAO） in electrolytes consisting of NaVO3. Their morphology and dements were characterized by scanning electron microscopy （SEM） and energy-dispersive X-ray （EDX） analysis. Phase composition and valence states of species in the films were characterized by X-ray diffraction （XRD） and X-ray photoelec- tron spectroscopy （XPS）. Ultraviolet-visible diffuse reflectance spectra （UV-Vis DRS） were also employed to evaluate the photophysical property of the films. The VEOs/TiO2 composite films show a sheet-like morphology. Not only V205 phase appears in the films when the NaVO3 concentration of the electrolyte is higher than 6,10 g/L and is loaded at the surface of anatase, but also V4＋ is incorporated into the crystal lattice of anatase. In comparison with pure TiO2 films the V2Os/TiO2 composite films exhibit significantly narrow band gap energy. The film prepared in an electrolyte consisting of NaVO3 with a concentration of 8.54 g/L exhibits the narrowest band gap energy, which is approximately 1.89 eV. The V2Os/TiO2 composite films also have the significantly enhanced visible light photocatalytic activity. The film prepared in an electrolyte consisting of NaVO3 with a concentration of 8.54 g/L exhibits the best photocatalytic activity and about 93% of rhodamine is degraded after 14 h visible light radiation.展开更多
Titanium and its alloys are widely used in the aerospace, marine, and biomedical industry due to their unique bulk properties such as high strength-to-weight ratio and melting temperature, good corrosion resistance, a...Titanium and its alloys are widely used in the aerospace, marine, and biomedical industry due to their unique bulk properties such as high strength-to-weight ratio and melting temperature, good corrosion resistance, and favorable biocom- patibility. However, in some applications, com- ponents made of titanium or titanium alloys exhibit poor wear resistance under stationary or dynamic loading as well as contact corrosion manifested by the relatively negative standard electrode potential （-1.63 V ） . In order to improve the surface properties of titanium and its alloys, several techniques such as PVD （ physical vapor deposition ） /CVD （chemical vapor deposition ） coatings,展开更多
Samples with two different shapes of 2024 aluminum alloy were treated with micro-arc oxidation (MAO), and the formation process and mechanism of oxidation film was analyzed. The results show that different geometrical...Samples with two different shapes of 2024 aluminum alloy were treated with micro-arc oxidation (MAO), and the formation process and mechanism of oxidation film was analyzed. The results show that different geometrical curvature of the material has an influence upon the uniformity of films and the corrosion-resistance.展开更多
Coatings on the surface of Mg alloys are inevitably damaged during their practical applications,and corrosion can easily initiate from the damaged areas to accelerate the failure of Mg parts.A dual self-healing coatin...Coatings on the surface of Mg alloys are inevitably damaged during their practical applications,and corrosion can easily initiate from the damaged areas to accelerate the failure of Mg parts.A dual self-healing coating has already been developed to solve this problem in our previous work.Considering the practical application of this coating,it is necessary to investigate its service behavior in atmospheric environment.Thus,the corrosion behavior of AM60 Mg substrate with and without the self-healing coating was compared in Shenyang industrial atmospheric environment.The results show that the enrichment of sediments and rainwater on the scratch areas can accelerate the corrosion of the exposed Mg substrate.The inhibitors can be released from the damaged coating to inhibit corrosion.The dual self-healing coating shows better inhibition ability to narrow scratches due to the higher inhibitor concentration and less resumption.Also,the coating with wide scratches displays enough inhibition ability as well.The dual self-healing coating is a good alternative for Mg alloy parts in the practical applications.展开更多
We report that the composites of ZnO/porous Si （PS） can exhibit intensively white photoluminescence （PL） under proper excitation wavelength. The PS sample is formed by electrochemical anodization of n-type （111）...We report that the composites of ZnO/porous Si （PS） can exhibit intensively white photoluminescence （PL） under proper excitation wavelength. The PS sample is formed by electrochemical anodization of n-type （111） silicon. ZnO films are then deposited on the PS surface by pulsed laser deposition （PLD）. ZnO is transparent in the visible region, so the red PL from PS can be transmitted through the ZnO films. White PL from the ZnO layer on PS can be obtained, which consists of blue-green emission from ZnO and red emission from PS. The x-ray diffraction （XRD） pattern shows that the ZnO films deposited on PS surface are non-crystalline. Due to the roughness of the PS surface, some cracks appear in the ZnO films, which could be seen from the scanning electron microscopy （SEM） images.展开更多
基金Project(gf200901002)supported by the Open Research Fund of National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology of Nanchang Hangkong University,China
文摘ZrO2/TiO2 composite photocatalytic film was produced on the pure titanium substrate using in-situ Zr（OH）4 colloidal particle by the micro-arc oxidation technique and characterized by scanning electron microscope （SEM）, energy dispersive X-ray （EDX）, X-ray diffraction （XRD） and ultraviolet-visible （UV-Vis） spectrophotometer. The composite film shows a lamellar and porous structure which consists of anatase, futile and ZrO2 phases. The optical absorption edge of film is shifted to longer wavelength when ZrO2 is introduced to TiO2. Furthermore, the photocatalytic reaction rate constants of degradation of rhodamine B solution with ZrO2/TiO2 composite film and pure TiO2 film under ultraviolet irradiation are measured as 0.0442 and 0.0186 h 1, respectively.
基金financial support by the National Natural Science Foundation of China(No.51171198)National Key Basic Research Program of China(No.2013CB632205)the International Science&Technology Cooperation Program of China(2011DFA50904).
文摘Micro-arc oxidation(MAO)is one of the promising methods to improve the corrosion resistance of magnesium alloys.However,there are plenty of micro-pores in the traditional MAO films,deteriorating their protection property.A novel self-sealing pore MAO film was developed in this paper.The morphologies and chemical composition of the film were detected by scanning electron microscopy(SEM)and energy dispersive X-ray spectroscopy(EDX).The corrosion behavior was investigated by electrochemical and salt spray tests.The possible film formation and corrosion mechanisms were proposed.The self-sealing pore film presents a blue appearance.Most of the micro-pores in the surface of the film are sealed during the film formation process.The chemical composition of the film mainly contains Mg,O,Ti,F and P.The self-sealing pore film exhibits better corrosion resistance compared with the traditional silicate film.Especially,the self-sealing pore film keeps intact after salt spray test for 2000 h,which can be attributed to its high compactness.
基金supported by the National Basic Research Priorities Program of China (No.2007CB936601)the National Natural Science Foundation of China (Nos.10876017 and 91023037)
文摘In-situ pure TiO2 and Fe-doped TiO2 thin films were synthesized on Ti plates via the micro-arc oxidation （MAO） technique. The as-fabricated anatase TiO2 thin film-based conductometric sensors were employed to measure the gas sensitivity to ethanol. The results showed that Fe ions could be easily introduced into the MAO-TiO2 thin films by adding precursor K4（FeCN）6＇3H20 into the NaaPO4 electrolyte. The amount of doped Fe ions increased almost linearly with the concentration of Kg（FeCN）63H20 increasing, eventually affecting the ethanol sensing performances of TiO2 thin films. It was found that the enhanced sensor signals obtained had an optimal concentration of Fe dopant （1.28at%）, by which the maximal gas sensor signal to 1000 ppm ethanol was estimated to be 7.91 at 275℃. The response time was generally reduced by doped Fe ions, which could be ascribed to the increase of oxygen vacancies caused by Fe3＋ substituting for Ti4＋.
基金the Open Research Fund of the National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology in Nanchang Hangkong University(No.gf200901002)the Analytical and Testing Center of Huazhong University of Science and Technology
文摘V2Os/TiO2 composite films were prepared on pure titanium substmtes via micro-arc oxidation （MAO） in electrolytes consisting of NaVO3. Their morphology and dements were characterized by scanning electron microscopy （SEM） and energy-dispersive X-ray （EDX） analysis. Phase composition and valence states of species in the films were characterized by X-ray diffraction （XRD） and X-ray photoelec- tron spectroscopy （XPS）. Ultraviolet-visible diffuse reflectance spectra （UV-Vis DRS） were also employed to evaluate the photophysical property of the films. The VEOs/TiO2 composite films show a sheet-like morphology. Not only V205 phase appears in the films when the NaVO3 concentration of the electrolyte is higher than 6,10 g/L and is loaded at the surface of anatase, but also V4＋ is incorporated into the crystal lattice of anatase. In comparison with pure TiO2 films the V2Os/TiO2 composite films exhibit significantly narrow band gap energy. The film prepared in an electrolyte consisting of NaVO3 with a concentration of 8.54 g/L exhibits the narrowest band gap energy, which is approximately 1.89 eV. The V2Os/TiO2 composite films also have the significantly enhanced visible light photocatalytic activity. The film prepared in an electrolyte consisting of NaVO3 with a concentration of 8.54 g/L exhibits the best photocatalytic activity and about 93% of rhodamine is degraded after 14 h visible light radiation.
文摘Titanium and its alloys are widely used in the aerospace, marine, and biomedical industry due to their unique bulk properties such as high strength-to-weight ratio and melting temperature, good corrosion resistance, and favorable biocom- patibility. However, in some applications, com- ponents made of titanium or titanium alloys exhibit poor wear resistance under stationary or dynamic loading as well as contact corrosion manifested by the relatively negative standard electrode potential （-1.63 V ） . In order to improve the surface properties of titanium and its alloys, several techniques such as PVD （ physical vapor deposition ） /CVD （chemical vapor deposition ） coatings,
文摘Samples with two different shapes of 2024 aluminum alloy were treated with micro-arc oxidation (MAO), and the formation process and mechanism of oxidation film was analyzed. The results show that different geometrical curvature of the material has an influence upon the uniformity of films and the corrosion-resistance.
基金This work was supported by the National Natural Science Foundation of China(No.51671199)the National Key Research and Development Program of China(No.2016 YFB0301105).
文摘Coatings on the surface of Mg alloys are inevitably damaged during their practical applications,and corrosion can easily initiate from the damaged areas to accelerate the failure of Mg parts.A dual self-healing coating has already been developed to solve this problem in our previous work.Considering the practical application of this coating,it is necessary to investigate its service behavior in atmospheric environment.Thus,the corrosion behavior of AM60 Mg substrate with and without the self-healing coating was compared in Shenyang industrial atmospheric environment.The results show that the enrichment of sediments and rainwater on the scratch areas can accelerate the corrosion of the exposed Mg substrate.The inhibitors can be released from the damaged coating to inhibit corrosion.The dual self-healing coating shows better inhibition ability to narrow scratches due to the higher inhibitor concentration and less resumption.Also,the coating with wide scratches displays enough inhibition ability as well.The dual self-healing coating is a good alternative for Mg alloy parts in the practical applications.
基金Supported by the Natural Science Foundation of Shandong Province under Grant No Y2002A09.
文摘We report that the composites of ZnO/porous Si （PS） can exhibit intensively white photoluminescence （PL） under proper excitation wavelength. The PS sample is formed by electrochemical anodization of n-type （111） silicon. ZnO films are then deposited on the PS surface by pulsed laser deposition （PLD）. ZnO is transparent in the visible region, so the red PL from PS can be transmitted through the ZnO films. White PL from the ZnO layer on PS can be obtained, which consists of blue-green emission from ZnO and red emission from PS. The x-ray diffraction （XRD） pattern shows that the ZnO films deposited on PS surface are non-crystalline. Due to the roughness of the PS surface, some cracks appear in the ZnO films, which could be seen from the scanning electron microscopy （SEM） images.
