Calcium titanate doped with praseodymium was prepared through solid state reaction and it exhibited intense red emission at 612 nm. Phosphors were characterized for photoluminescence, thermo-luminescence and afterglow...Calcium titanate doped with praseodymium was prepared through solid state reaction and it exhibited intense red emission at 612 nm. Phosphors were characterized for photoluminescence, thermo-luminescence and afterglow emissions. Study of effects of rare earths on photoluminescence as well as afterglow intensity was reported. Presence of gadolinium enhanced luminescence. Presence of some monovalent ions enhanced both afterglow and photoluminescence emission. Thermo-luminescence glow curves were analyzed and ...展开更多
Supporting sustainable green energy systems,there is a big demand gap for grid energy storage.Sodiumion storage,especially sodium-ion batteries(SIBs),have advanced significantly and are now emerging as a feasible alte...Supporting sustainable green energy systems,there is a big demand gap for grid energy storage.Sodiumion storage,especially sodium-ion batteries(SIBs),have advanced significantly and are now emerging as a feasible alternative to the lithium-ion batteries equivalent in large-scale energy storage due to their natural abundance and prospective inexpensive cost.Among various anode materials of SIBs,beneficial properties,such as outstanding stability,great abundance,and environmental friendliness,make sodium titanates(NTOs),one of the most promising anode materials for the rechargeable SIBs.Nevertheless,there are still enormous challenges in application of NTO,owing to its low intrinsic electronic conductivity and collapse of structure.The research on NTOs is still in its infancy;there are few conclusive reviews about the specific function of various modification methods.Herein,we summarize the typical strategies of optimization and analysis the fine structures and fabrication methods of NTO anodes combined with the application of in situ characterization techniques.Our work provides effective guidance for promoting the continuous development,equipping NTOs in safety-critical systems,and lays a foundation for the development of NTO-anode materials in SIBs.展开更多
In the present research, the effect of CeO2 dopant on the fabrication of transparent lithium aluminosilicate titanate (LAST) glass ceramics was investigated. Nanocrystallineβ-quartz solid solution (s.s.) was obse...In the present research, the effect of CeO2 dopant on the fabrication of transparent lithium aluminosilicate titanate (LAST) glass ceramics was investigated. Nanocrystallineβ-quartz solid solution (s.s.) was observed to be the main phase crystallized in this system. Com-parable refractive indices of the glassy matrix andβ-quartz s.s., as well as the incorporation of very fine grains size were determined as the main reasons for retaining the transparency of the glass ceramics. CeO2 was introduced as a suitable optical agent, playing a role as a network modifier in the glass ceramics, because it does not accelerate the growth process and retards the extended growth of crystals. Optical investi-gations indicate that the Fermi energy level, direct and indirect band gaps, and Urbach energy decrease with increasing nanocrystal content in the glassy matrix of specimens, which can be related to the expansion of conduction band, the enhancement of ionic bonds in the crystal lat-tice, and the enhancement of structural arrangement degree, respectively.展开更多
Photogenerated charge separation and transfer is one of the bottleneck steps in photocatalysis,and efficient charge separation strategies are strongly desired.Here,mimicking the electron transport chain in natural pho...Photogenerated charge separation and transfer is one of the bottleneck steps in photocatalysis,and efficient charge separation strategies are strongly desired.Here,mimicking the electron transport chain in natural photosynthesis,we report the design and fabrication of a charge transfer chain using bismuth-based semiconductor as a proof-of-concept.In view of the thermodynamic energy band positions and structural similarity based on the density functional theory(DFT)analysis,heterostructured combination ofα-Bi_(2)O_(3),perovskite-like Bi_(4)Ti_(3)O_(12),and sillenite Bi12TiO20 was designed for fabrication of charge transfer chain.By tuning the molar ratio of Bi and Ti precursors,the Bi_(4)Ti_(3)O_(12)and Bi12TiO20 particles were formed on the surface ofα-Bi_(2)O_(3)by an insitu transformation process,giving rise to Bi_(12)TiO_(20)-Bi_(4)Ti_(3)O_(12)/α-Bi_(2)O_(3)composites with charge transfer chain.We propose that the effective charge transfer is accomplished amongα-Bi_(2)O_(3),Bi12TiO20,and Bi_(4)Ti_(3)O_(12),which significantly improves the photogenerated charge separation and transfer,as indicated by photoluminescene,time-resolved photoluminescene,and electrochemical impedance spectra results.As expected,the Bi_(12)TiO_(20)-Bi_(4)Ti_(3)O_(12)/α-Bi_(2)O_(3)shows the superior photocatalytic activity for the degradation of environmental pollutants with high concentration.Even for the refractory pollutants like 4-chlorophenol,the optimal Bi_(12)TiO_(20)-Bi_(4)Ti_(3)O_(12)/α-Bi_(2)O_(3)composite shows 28 times higher than that ofα-Bi_(2)O_(3)for photocatalytic degradation,verifying the superiority of photogenerated charge transfer chain in photocatalysis.This work demonstrates the feasibility of the charge transfer chain strategy to boost the photogenerated charge separation,which is of great significance for designing energy and environmental-related materials in heterogonous photocatalysis.展开更多
XRD measurements were carried out on plasma sprayed titanates BaTiO_(3),CaTiO_(3),MgTiO_(3)and a mixture of the last two.Samples were tested as dielectrics and volume resistivities of the materials were also summarize...XRD measurements were carried out on plasma sprayed titanates BaTiO_(3),CaTiO_(3),MgTiO_(3)and a mixture of the last two.Samples were tested as dielectrics and volume resistivities of the materials were also summarized.Microwave microscopy was used for mapping of the dielectric response of selected samples.The results show differences in the crystal structure between plasma sprayed coatings and feedstock powders in the case of BaTiO_(3)and MgTiO_(3)whereas CaTiO_(3)is crystalograffically identical with its feedstock.The reason can be found in larger sensitivity of BaTiO_(3)and MgTiO_(3)to the reductive conditions at plasma spraying whereas CaTiO_(3)seems to be rather inert from this viewpoint.However CaTiO_(3)exhibits anomalous dielectric losses because of intrinsic conductivity.展开更多
Recently,aqueous zinc-ion batteries with intrinsic safety,low cost,and environmental benignity have attracted tremendous research interest.However,zinc dendrites,harmful side reactions,and zinc metal corrosion stand i...Recently,aqueous zinc-ion batteries with intrinsic safety,low cost,and environmental benignity have attracted tremendous research interest.However,zinc dendrites,harmful side reactions,and zinc metal corrosion stand in the way.Herein,we use lepidocrocite-type sodium titanate hollow microspheres assembled by nanotubes to constitute an artificial solid electrolyte interface layer on the zinc metal electrode.Thanks to the hierarchical structure with abundant open voids,negative-charged layered framework,low hydrophilicity,electrically insulting nature,and large ionic conductivity,the sodium titanate coating layer can effectively homogenize the electric field,promote the Zn^(2+)ion transfer,guide the Zn^(2+)ion flux,reduce the desolvation barrier,improve the exchange current density,and accommodate the plated zinc metal.Consequently,this coating layer can effectively suppress zinc dendrites and other unfavorable effects.With this coating layer,the Zn//Zn symmetric cell is able to provide an impressive cumulative zinc plating capacity of 1375 m Ah cm^(-2) at a current density of 5 m A cm^(-2).This coating layer also contributes to significantly improved electrochemical performances of Zn//MnO_(2) battery and zincion hybrid capacitor.This work offers new insights into the modifications of zinc metal electrodes.展开更多
By using nitric acid as the fuel, the lead-free ceramic of Ba(Ti1-x,Mgx)O3 (x = 0.31) was prepared by auto combustion method (ACM). To make a comparison, this ceramic was also prepared using mixed oxide method (MOM). ...By using nitric acid as the fuel, the lead-free ceramic of Ba(Ti1-x,Mgx)O3 (x = 0.31) was prepared by auto combustion method (ACM). To make a comparison, this ceramic was also prepared using mixed oxide method (MOM). By X-ray diffraction, the phase structures of two samples were studied, and the results showed that rising temperatures would reduce unwanted phases. The piezoelectric and electrical properties as a function of calcination and sintering temperatures were investigated. The results showed that the outstanding electrical properties were obtained for nanoceramic with this composition. The SEM image of the grain size was estimated around 2 micrometers, and the grain size increased with the increasing of sintering temperature for two samples. The curie temperature of the BMT-ACM was 126°C and it’s significantly larger than the curie temperature of BMT-MOM which was 118°C. The results of electrical properties emphasized that the synthesis optimum temperature for two samples was about 1200°C and it was the best temperature that led to improved properties such as dielectric constant, polarization and piezoelectric coefficients.展开更多
Chiral titanate reagents were prepared for inducing asymmetric syntheses of substituted benzhydrols from Grignard reagents and aldehydes. The solvents, reaction temperature and exchange of reactants by crossing experi...Chiral titanate reagents were prepared for inducing asymmetric syntheses of substituted benzhydrols from Grignard reagents and aldehydes. The solvents, reaction temperature and exchange of reactants by crossing experiments were investigated. Favorable attack of the nucleophile upon the aromatic aldehydes' prochiral face was proposed, the absolute configurations of the synthesized benzhydrols were suggested, and a preliminary reaction mechanism was described.展开更多
Uses of layered alkali titanates(A_(2)Ti_(n)O_(2n+1);Na_(2)Ti_(3)O_(7),K_(2)Ti_(4)O_(9),and Cs_(2)Ti_(5)O_(11))for energy and environmental issues are summarized.Layered alkali titanates of various structural types an...Uses of layered alkali titanates(A_(2)Ti_(n)O_(2n+1);Na_(2)Ti_(3)O_(7),K_(2)Ti_(4)O_(9),and Cs_(2)Ti_(5)O_(11))for energy and environmental issues are summarized.Layered alkali titanates of various structural types and compositions are regarded as a class of nanostructured materials based on titanium oxide frameworks.If compared with commonly known titanium dioxides(anatase and rutile),materials design based on layered alkali titanates is quite versatile due to the unique structure(nanosheet)and morphological characters(anisotropic particle shape).Recent development of various synthetic methods(solid-state reaction,flux method,and hydrothermal reaction)for controlling the particle shape and size of layered alkali titanates are discussed.The ion exchange ability of layered alkali titanate is used for the collection of metal ions from water as well as a way of their functionalization.These possible materials design made layered alkali titanates promising for energy(including catalysis,photocatalysts,and battery)and environmental(metal ion concentration from aqueous environments)applications.展开更多
We report the first example of carbon nanotube(CNT)-like assembly of the titanium(Ti)framework,Ti oxo inorganic cluster(Ti6O6)hexagonal rings into a titanium oxide(Ti–O)nanotube,prepared by ionothermal synthesis.As d...We report the first example of carbon nanotube(CNT)-like assembly of the titanium(Ti)framework,Ti oxo inorganic cluster(Ti6O6)hexagonal rings into a titanium oxide(Ti–O)nanotube,prepared by ionothermal synthesis.As determined by single-crystal X-ray diffraction analysis,the Ti–O nanotube arrays,stabilized by sulfate ligands,assumed proper parallel alignment with each other and were separated by supramolecular interactions with surrounding EMIm(1-Ethyl-3-methylimidazolium)counter cations.Our stability studies indicated that the Ti–O nanotube obtained is indeed stable in air and various solvents.Also,it could maintain its structure upon heating to∼300°C.Moreover,inside the pores of the Ti–O nanotubes,a rare water molecules nanoconfinement behavior was observed at room temperature.Further,our current developed Ti–O nanotube arrays exhibited selective water adsorption over methanol and ethanol,showing potential applications for miscible solvents separations.Finally,these Ti–O nanotubes demonstrated typical semiconductive characteristics,with the electrical conductivity increasing four orders of magnitude,ranging from 3.15×10^(−10)–1.03×10^(−6)S/cm,as the temperature increased from 35 to 135°C.This work represents a milestone in constructing inorganic Ti–O nanotube arrays with atomically precise structural information for applications as visible-lightinduced photocatalysts,semiconductors,sensors,and optoelectronics.展开更多
K2Ti2O5 and LixK2-xTi2O5 samples with varying K contents (x=0.125, 0.15, 0.3), targeted on removal of two main environmental pollutants: PM and NOx, were synthesized by the solid state method using TiO2, KNO3 and L...K2Ti2O5 and LixK2-xTi2O5 samples with varying K contents (x=0.125, 0.15, 0.3), targeted on removal of two main environmental pollutants: PM and NOx, were synthesized by the solid state method using TiO2, KNO3 and LiOH-H2O as starting materials and were characterized by X-ray diffractometry, scanning electron microscopy, and BET. The catalytic activity of titanate catalysts on PM oxidation was evaluated using the temperature programmed oxidation (TPO) method. The test results showed that the perovskite structure of K2Ti205 was still retained after doping a small amount of Li, and the catalytic performance of LixK2-xTi2O5 had been improved significantly compared with that of K2Ti2O5. Li0.15K1.85Ti205 catalyst had the highest catalytic activity with an ignition temperature of 210℃ and a peak temperature of 290℃. The catalytic activity of both K2Ti2O5 and LixK2-xTi2O5 under intimate contact was higher than that under loose contact. When the exhaust gas flow rate was around 100 mL/min, the catalyst samples showed a highest activity. The Li doped K2Ti2O5 could be an excellent candidate for PM oxidation due to its high oxidation activity, water stability, resistance to sulfur poisoning and economical advantages.展开更多
文摘Calcium titanate doped with praseodymium was prepared through solid state reaction and it exhibited intense red emission at 612 nm. Phosphors were characterized for photoluminescence, thermo-luminescence and afterglow emissions. Study of effects of rare earths on photoluminescence as well as afterglow intensity was reported. Presence of gadolinium enhanced luminescence. Presence of some monovalent ions enhanced both afterglow and photoluminescence emission. Thermo-luminescence glow curves were analyzed and ...
基金supported by projects from the National Natural Science Foundation of China(U20A20145)the Open Project of State Key Laboratory of Environment-friendly Energy Materials(20kfhg07)+6 种基金Distinguished Young Foundation of Sichuan Province(2020JDJQ0027)2020 Strategic Cooperation Project between Sichuan University and the Zigong Municipal People's Government(2020CDZG-09)State Key Laboratory of Polymer Materials Engineering(sklpme2020-3-02)Sichuan Provincial Department of Science and Technology(2020YFG0471,2020YFG0022,2022YFG0124)Sichuan Province Science and Technology Achievement Transfer and Transformation Project(21ZHSF0111)Sichuan University Postdoctoral Interdisciplinary Innovation Fund(2021SCU12084)Start-up funding of Chemistry and Chemical Engineering Guangdong Laboratory(2122010)。
文摘Supporting sustainable green energy systems,there is a big demand gap for grid energy storage.Sodiumion storage,especially sodium-ion batteries(SIBs),have advanced significantly and are now emerging as a feasible alternative to the lithium-ion batteries equivalent in large-scale energy storage due to their natural abundance and prospective inexpensive cost.Among various anode materials of SIBs,beneficial properties,such as outstanding stability,great abundance,and environmental friendliness,make sodium titanates(NTOs),one of the most promising anode materials for the rechargeable SIBs.Nevertheless,there are still enormous challenges in application of NTO,owing to its low intrinsic electronic conductivity and collapse of structure.The research on NTOs is still in its infancy;there are few conclusive reviews about the specific function of various modification methods.Herein,we summarize the typical strategies of optimization and analysis the fine structures and fabrication methods of NTO anodes combined with the application of in situ characterization techniques.Our work provides effective guidance for promoting the continuous development,equipping NTOs in safety-critical systems,and lays a foundation for the development of NTO-anode materials in SIBs.
文摘In the present research, the effect of CeO2 dopant on the fabrication of transparent lithium aluminosilicate titanate (LAST) glass ceramics was investigated. Nanocrystallineβ-quartz solid solution (s.s.) was observed to be the main phase crystallized in this system. Com-parable refractive indices of the glassy matrix andβ-quartz s.s., as well as the incorporation of very fine grains size were determined as the main reasons for retaining the transparency of the glass ceramics. CeO2 was introduced as a suitable optical agent, playing a role as a network modifier in the glass ceramics, because it does not accelerate the growth process and retards the extended growth of crystals. Optical investi-gations indicate that the Fermi energy level, direct and indirect band gaps, and Urbach energy decrease with increasing nanocrystal content in the glassy matrix of specimens, which can be related to the expansion of conduction band, the enhancement of ionic bonds in the crystal lat-tice, and the enhancement of structural arrangement degree, respectively.
基金supported by the National Natural Science Foundation of China(No.22172068)the Natural Science Foundation of Jiangsu Province(No.BK20221485)+2 种基金the Liaoning Revitalization Talents Program(No.XLYC1902065)the Scientific Research Fund of Liaoning Provincial Department of Education(No.LJKMZ20220747)the Talent Scientific Research Fund of LSHU(No.2016XJJ-012).
文摘Photogenerated charge separation and transfer is one of the bottleneck steps in photocatalysis,and efficient charge separation strategies are strongly desired.Here,mimicking the electron transport chain in natural photosynthesis,we report the design and fabrication of a charge transfer chain using bismuth-based semiconductor as a proof-of-concept.In view of the thermodynamic energy band positions and structural similarity based on the density functional theory(DFT)analysis,heterostructured combination ofα-Bi_(2)O_(3),perovskite-like Bi_(4)Ti_(3)O_(12),and sillenite Bi12TiO20 was designed for fabrication of charge transfer chain.By tuning the molar ratio of Bi and Ti precursors,the Bi_(4)Ti_(3)O_(12)and Bi12TiO20 particles were formed on the surface ofα-Bi_(2)O_(3)by an insitu transformation process,giving rise to Bi_(12)TiO_(20)-Bi_(4)Ti_(3)O_(12)/α-Bi_(2)O_(3)composites with charge transfer chain.We propose that the effective charge transfer is accomplished amongα-Bi_(2)O_(3),Bi12TiO20,and Bi_(4)Ti_(3)O_(12),which significantly improves the photogenerated charge separation and transfer,as indicated by photoluminescene,time-resolved photoluminescene,and electrochemical impedance spectra results.As expected,the Bi_(12)TiO_(20)-Bi_(4)Ti_(3)O_(12)/α-Bi_(2)O_(3)shows the superior photocatalytic activity for the degradation of environmental pollutants with high concentration.Even for the refractory pollutants like 4-chlorophenol,the optimal Bi_(12)TiO_(20)-Bi_(4)Ti_(3)O_(12)/α-Bi_(2)O_(3)composite shows 28 times higher than that ofα-Bi_(2)O_(3)for photocatalytic degradation,verifying the superiority of photogenerated charge transfer chain in photocatalysis.This work demonstrates the feasibility of the charge transfer chain strategy to boost the photogenerated charge separation,which is of great significance for designing energy and environmental-related materials in heterogonous photocatalysis.
文摘XRD measurements were carried out on plasma sprayed titanates BaTiO_(3),CaTiO_(3),MgTiO_(3)and a mixture of the last two.Samples were tested as dielectrics and volume resistivities of the materials were also summarized.Microwave microscopy was used for mapping of the dielectric response of selected samples.The results show differences in the crystal structure between plasma sprayed coatings and feedstock powders in the case of BaTiO_(3)and MgTiO_(3)whereas CaTiO_(3)is crystalograffically identical with its feedstock.The reason can be found in larger sensitivity of BaTiO_(3)and MgTiO_(3)to the reductive conditions at plasma spraying whereas CaTiO_(3)seems to be rather inert from this viewpoint.However CaTiO_(3)exhibits anomalous dielectric losses because of intrinsic conductivity.
基金the financial support from the National Natural Science Foundation of China(51902165)the Program of HighLevel Talents in Six Industries of Jiangsu Province(XCL-040)the Jiangsu Specially-Appointed Professor Program。
文摘Recently,aqueous zinc-ion batteries with intrinsic safety,low cost,and environmental benignity have attracted tremendous research interest.However,zinc dendrites,harmful side reactions,and zinc metal corrosion stand in the way.Herein,we use lepidocrocite-type sodium titanate hollow microspheres assembled by nanotubes to constitute an artificial solid electrolyte interface layer on the zinc metal electrode.Thanks to the hierarchical structure with abundant open voids,negative-charged layered framework,low hydrophilicity,electrically insulting nature,and large ionic conductivity,the sodium titanate coating layer can effectively homogenize the electric field,promote the Zn^(2+)ion transfer,guide the Zn^(2+)ion flux,reduce the desolvation barrier,improve the exchange current density,and accommodate the plated zinc metal.Consequently,this coating layer can effectively suppress zinc dendrites and other unfavorable effects.With this coating layer,the Zn//Zn symmetric cell is able to provide an impressive cumulative zinc plating capacity of 1375 m Ah cm^(-2) at a current density of 5 m A cm^(-2).This coating layer also contributes to significantly improved electrochemical performances of Zn//MnO_(2) battery and zincion hybrid capacitor.This work offers new insights into the modifications of zinc metal electrodes.
文摘By using nitric acid as the fuel, the lead-free ceramic of Ba(Ti1-x,Mgx)O3 (x = 0.31) was prepared by auto combustion method (ACM). To make a comparison, this ceramic was also prepared using mixed oxide method (MOM). By X-ray diffraction, the phase structures of two samples were studied, and the results showed that rising temperatures would reduce unwanted phases. The piezoelectric and electrical properties as a function of calcination and sintering temperatures were investigated. The results showed that the outstanding electrical properties were obtained for nanoceramic with this composition. The SEM image of the grain size was estimated around 2 micrometers, and the grain size increased with the increasing of sintering temperature for two samples. The curie temperature of the BMT-ACM was 126°C and it’s significantly larger than the curie temperature of BMT-MOM which was 118°C. The results of electrical properties emphasized that the synthesis optimum temperature for two samples was about 1200°C and it was the best temperature that led to improved properties such as dielectric constant, polarization and piezoelectric coefficients.
基金Supported by the Grant of National Natural Science Foundation of China the Organometallic Chemistry Laboratory of the Shanghai Institute of Organic Chemistry, Chinese Academy of Science
文摘Chiral titanate reagents were prepared for inducing asymmetric syntheses of substituted benzhydrols from Grignard reagents and aldehydes. The solvents, reaction temperature and exchange of reactants by crossing experiments were investigated. Favorable attack of the nucleophile upon the aromatic aldehydes' prochiral face was proposed, the absolute configurations of the synthesized benzhydrols were suggested, and a preliminary reaction mechanism was described.
基金This work was supported by the Research Chair Grant 2017(Grant No.FDA-CO-2560-5655)from the National Science and Technology Development Agency(NSTDA),Thailandthe Program Management Unit for Human Resources&Institutional Development,Research and Innovation,NXPO(B05F630117)Thailand,and the MEXT Promotion of Distinctive Joint Research Center Program(Grant No.JPMXP0618217662).
文摘Uses of layered alkali titanates(A_(2)Ti_(n)O_(2n+1);Na_(2)Ti_(3)O_(7),K_(2)Ti_(4)O_(9),and Cs_(2)Ti_(5)O_(11))for energy and environmental issues are summarized.Layered alkali titanates of various structural types and compositions are regarded as a class of nanostructured materials based on titanium oxide frameworks.If compared with commonly known titanium dioxides(anatase and rutile),materials design based on layered alkali titanates is quite versatile due to the unique structure(nanosheet)and morphological characters(anisotropic particle shape).Recent development of various synthetic methods(solid-state reaction,flux method,and hydrothermal reaction)for controlling the particle shape and size of layered alkali titanates are discussed.The ion exchange ability of layered alkali titanate is used for the collection of metal ions from water as well as a way of their functionalization.These possible materials design made layered alkali titanates promising for energy(including catalysis,photocatalysts,and battery)and environmental(metal ion concentration from aqueous environments)applications.
基金This research was made possible as a result of a generous grant from National Natural Science Foundation of China(21673238 and 21922111)National Key Research and Development Program of China(2018YFA0208600)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000)the Natural Science Foundation of Fujian Province(2017J06009).
文摘We report the first example of carbon nanotube(CNT)-like assembly of the titanium(Ti)framework,Ti oxo inorganic cluster(Ti6O6)hexagonal rings into a titanium oxide(Ti–O)nanotube,prepared by ionothermal synthesis.As determined by single-crystal X-ray diffraction analysis,the Ti–O nanotube arrays,stabilized by sulfate ligands,assumed proper parallel alignment with each other and were separated by supramolecular interactions with surrounding EMIm(1-Ethyl-3-methylimidazolium)counter cations.Our stability studies indicated that the Ti–O nanotube obtained is indeed stable in air and various solvents.Also,it could maintain its structure upon heating to∼300°C.Moreover,inside the pores of the Ti–O nanotubes,a rare water molecules nanoconfinement behavior was observed at room temperature.Further,our current developed Ti–O nanotube arrays exhibited selective water adsorption over methanol and ethanol,showing potential applications for miscible solvents separations.Finally,these Ti–O nanotubes demonstrated typical semiconductive characteristics,with the electrical conductivity increasing four orders of magnitude,ranging from 3.15×10^(−10)–1.03×10^(−6)S/cm,as the temperature increased from 35 to 135°C.This work represents a milestone in constructing inorganic Ti–O nanotube arrays with atomically precise structural information for applications as visible-lightinduced photocatalysts,semiconductors,sensors,and optoelectronics.
基金supports provided for this research by the Education Department of Liaoning Province of China (No. 2009T061)Ministry of Education of China (No. [2010] 1561)
文摘K2Ti2O5 and LixK2-xTi2O5 samples with varying K contents (x=0.125, 0.15, 0.3), targeted on removal of two main environmental pollutants: PM and NOx, were synthesized by the solid state method using TiO2, KNO3 and LiOH-H2O as starting materials and were characterized by X-ray diffractometry, scanning electron microscopy, and BET. The catalytic activity of titanate catalysts on PM oxidation was evaluated using the temperature programmed oxidation (TPO) method. The test results showed that the perovskite structure of K2Ti205 was still retained after doping a small amount of Li, and the catalytic performance of LixK2-xTi2O5 had been improved significantly compared with that of K2Ti2O5. Li0.15K1.85Ti205 catalyst had the highest catalytic activity with an ignition temperature of 210℃ and a peak temperature of 290℃. The catalytic activity of both K2Ti2O5 and LixK2-xTi2O5 under intimate contact was higher than that under loose contact. When the exhaust gas flow rate was around 100 mL/min, the catalyst samples showed a highest activity. The Li doped K2Ti2O5 could be an excellent candidate for PM oxidation due to its high oxidation activity, water stability, resistance to sulfur poisoning and economical advantages.