Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properti...Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properties of rare earth luminescent materials, with the goal of uncovering their importance in luminescence mechanisms and applications. Through theoretical calculations and experimental methods, we conducted in-depth analyses on materials composed of various rare earth elements. Regarding electronic structure, we utilized computational techniques such as density functional theory to investigate the band structure, valence state distribution, and electronic density of states of rare earth luminescent materials. The results indicate that the electronic structural differences among different rare earth elements notably influence their luminescence performance, providing crucial clues for explaining the luminescence mechanism. In terms of optical properties, we systematically examined the material’s optical behaviors through fluorescence spectroscopy, absorption spectroscopy, and other experimental approaches. We found that rare earth luminescent materials exhibit distinct absorption and emission characteristics at different wavelengths, closely related to the transition processes of their electronic energy levels. Furthermore, we studied the influence of varying doping concentrations and impurities on the material’s optical properties. Experimental outcomes reveal that appropriate doping can effectively regulate the emission intensity and wavelength, offering greater possibilities for material applications. In summary, this study comprehensively analyzed the electronic structure and optical properties of rare earth luminescent materials, providing deep insights into understanding their luminescence mechanisms and potential value in optoelectronic applications. In the future, these research findings will serve as crucial references for the technological advancement in fields such as LEDs, lasers, and bioimaging.展开更多
Solid-state white LED will be a new generation of energy-saving light source in 21 century. In order to emitting white light, one of important approaches is using luminescence conversion technology with rare earth pho...Solid-state white LED will be a new generation of energy-saving light source in 21 century. In order to emitting white light, one of important approaches is using luminescence conversion technology with rare earth phosphors, which can be excited by the 460 nm blue light or 400 nm near violet light emitted from the InGaN chip and then emit white light. The rare earths doped phosphors prepared by us such as YAG∶Ce 3+, Ca 1-xSrxS∶Eu 2+, Ga2S3∶Eu 2+, MGa2S4∶Eu 2+（M=Ca, Sr, Ba）, SrGa 2+xS 4+y∶Eu 2+, （Ca 1-xSrx）Se∶Eu 2+, SrLaGa3S6O∶Eu 2+, （M1, M2） 10（PO4）6X2 （M1=Ca, Sr, Ba; M2=Eu, Mn; X=F, Cl, Br） and NaEu 0.92Sm 0.08（MoO4）2 were reported. They emit blue, green, yellow or red color light. Some white LEDs were made by these phosphors with blue or near violet InGaN chips and their chromaticity coordinate （x, y）, correlated color temperature TC, and color rendering index Ra are reported.展开更多
Hybrid materials incorporating Eu-(TTA)3·2H20 (hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregn...Hybrid materials incorporating Eu-(TTA)3·2H20 (hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of Eu3+ under UV light exci-tation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.展开更多
1 Results The size of nanoscale rare earth luminescent materials is often smaller than that of the excitement or emission wavelength,and it has amazing surface state density. Therefore,it shows a lot of new luminescen...1 Results The size of nanoscale rare earth luminescent materials is often smaller than that of the excitement or emission wavelength,and it has amazing surface state density. Therefore,it shows a lot of new luminescent phenomena such as the shift of CTS,the broadening of emission peaks,the variation of fluorescent lifetimes and quantum efficiency,and the increase of quenching concentration.It is not only of academic interest but also of technological importance for advanced phosphor applications to rese...展开更多
A new method of preparation of irradiative material by using rare earth as luminophor and inorganic powder as base nucleus was presented.Rare earth was used to make colloid, which was mixed with base nucleus solution,...A new method of preparation of irradiative material by using rare earth as luminophor and inorganic powder as base nucleus was presented.Rare earth was used to make colloid, which was mixed with base nucleus solution,where deposition/attachment reaction took place and rare earth was adhered onto the surface of base nucleus, hence yielding a new rare earth encapsulated irradiative material.Fluorescent spectrum analysis shows that this material possesses two emission peaks, one within 400 ～ 500 nm and the other within 580 ～ 700 nm, reflecting the luminous characteristics of original rare earth material.展开更多
Trivalent rare earth ions(Ln3+)have the unique elec-tronic configurations[Xe]4fn(n=0-14)and numerous energy levels,which endow rare earth luminescent mate-rials with many fascinating optical properties over a broad sp...Trivalent rare earth ions(Ln3+)have the unique elec-tronic configurations[Xe]4fn(n=0-14)and numerous energy levels,which endow rare earth luminescent mate-rials with many fascinating optical properties over a broad spectral region ranging from the ultraviolet(UV)to the near infrared(NIR);these include tunable atomic-like excitation/emission spectra,large Stokes/anti-Stokes shifts,long luminescent lifetimes,and excellent photostability1-4.展开更多
Rare-earth doped luminescent nanomaterials are attractive and have many potential applications in health,energy,information and safety area[1].Similar to most chemical processes,the process to synthesize luminescent n...Rare-earth doped luminescent nanomaterials are attractive and have many potential applications in health,energy,information and safety area[1].Similar to most chemical processes,the process to synthesize luminescent nanomaterials is complicated and it needs a combination of a series of unit operations including mixing of the reactants.展开更多
Rare earth mineral composite materials were prepared using rare earths and natural far-infrared mineral materials. The influences of rare earth additive content and heat treatment temperature on the far infrared radia...Rare earth mineral composite materials were prepared using rare earths and natural far-infrared mineral materials. The influences of rare earth additive content and heat treatment temperature on the far infrared radiance were studied. The results show that the far infrared radiance of rare earth mineral composite materials is 0.93 when the rare earth additive content is 6% and heat treatment temperature is 750 ℃.展开更多
The antimicrobial effect of the Ag-White Carbon Black containing rare earth was investigated. Inorganic antibiotic materials consist of the antibacterial ion, the additive and the carrier. The sol-gel method was used ...The antimicrobial effect of the Ag-White Carbon Black containing rare earth was investigated. Inorganic antibiotic materials consist of the antibacterial ion, the additive and the carrier. The sol-gel method was used to prepare the white carbon black carrier. Ag+ was selected to be the antibacterial ion, and cerous nitrate was selected to be the additive. They were synthesized on the white carbon black carrier. The structures and properties of antibacterial material were characterized by inductively coupled plasma, particle size measurement instrument, fourier transform infrared and enumeration tests (Escherichia coli as experimental bacterium). Results showed that the amount of antibacterial ions and bacteriostasis rate of this new material are higher than those for the general Ag-antibacterial white carbon black (without containing rare earth). Ag+ was bound to white carbon black by ion exchange process and adsorption process. Bacteriostasis rate is over 99%, and the particle size can be extended down to 7 μm with a narrow size distribution. Other advantages of this material are good thermal and light stability. Furthermore, from the antibacterial experiment in rubber and the coating surface of metal, this new material showed promising results. The possible antibacterial mechanism was also proposed through all the experimental data in this study.展开更多
Rare earth composite materials radiating far-infrared rays were prepared according to far infrared absorption spectrum of main component in liquefied petroleum gas (LPG). The composite materials were characterized by ...Rare earth composite materials radiating far-infrared rays were prepared according to far infrared absorption spectrum of main component in liquefied petroleum gas (LPG). The composite materials were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transformed infrared spectra(FTIR). The results show that after the composite materials were calcined at 873 K for 4 h, FTIR spectra of rare earth composite materials display two new peaks at 1336 and 2926 cm-1 available for activating LPG.展开更多
Inorganic antibacterial materials consist of the antibacterial ions, the additives and the carrier. In this study, we synthesized a new inorganic antibacterialmaterial, of which Cu2+ and Ag+ were selected to be the bi...Inorganic antibacterial materials consist of the antibacterial ions, the additives and the carrier. In this study, we synthesized a new inorganic antibacterialmaterial, of which Cu2+ and Ag+ were selected to be the bi-component antibacterial ions, cerous nitrate served as the additives, and the white carbon black was chosen as the carrier, which was prepared by a sol-gel method. The as-synthesized antibacterial material was characterized by inductively coupled plasma, particle size measurement instrument, scanning electron microscope and enumeration tests. The result showed that the amount of antibacterial ions and bacteriostasis rate of this new material are higher than those for the single-ion inorganic antibacterial material. In addition, the particle size of this material can be extended down to 7 μm with a narrow size distribution. Other advantages of this material are its loose and dispersive structure, good thermal and light stability. From the antibacterial experiment in rubber and the coating surface of metal, this new material showed promising results. The possible antibacterial mechanism was also proposed through all the experimental data in this study.展开更多
The bi rare earth complexes EuTb( m MBA) 6(phen) 2·2H 2O, TbY( m MBA) 6(phen) 2·2H 2O were synthesized by the reaction of RECl 3 with m methylbenzoic acid and 1,10 phenanthroline in ethanol solution, where m...The bi rare earth complexes EuTb( m MBA) 6(phen) 2·2H 2O, TbY( m MBA) 6(phen) 2·2H 2O were synthesized by the reaction of RECl 3 with m methylbenzoic acid and 1,10 phenanthroline in ethanol solution, where m MBA=m methylbenzoate and phen=1,10 phenanthroline. The luminescence properties of the title complexes were studied in comparison with the corresponding complexes Eu 2( m MBA) 6(phen) 2·2H 2O and Tb 2( m MBA) 6(phen) 2·2H 2O respectively. The results indicate that the emission intensity from europium ion can be greatly enhanced by the terbium ion, while the emission from terbium ion was strongly quenched by europium ion in EuTb( m MBA) 6(phen) 2·2H 2O; the emission intensity from terbium ion can be greatly enhanced by yttrium ion in TbY( m MBA) 6(phen) 2·2H 2O. The mechanism about the results was discussed.展开更多
Through the addition of Y, Sm and Ce in Al2O3/(W, Ti)C ceramic matrix, it was found that the amount and kind of the added rare earth elements have some different influences on the mechanical properties and wear resist...Through the addition of Y, Sm and Ce in Al2O3/(W, Ti)C ceramic matrix, it was found that the amount and kind of the added rare earth elements have some different influences on the mechanical properties and wear resistance of the composite. Under the present experimental conditions, the flank wear curves of the selected ceramic tool materials when machining the hardened tool steel obeyed the wear law well. But wear resistance of different ceramic materials varied with each other. Wear resistance of rare earth ceramic tool materials was higher than that of the corresponding materials without rare earth. Wear modes of the developed Al2O3/(W, Ti)C series rare earth ceramic tool materials were mainly flank wear and accompanied with slight crater wear.展开更多
The nanocomposite materials containing rare earths, titanium dioxide and clay (RE/TiO2/Clay) were characterized and tested for the photocatalytic decomposition of formaldehyde. The results show that nanocomposite mate...The nanocomposite materials containing rare earths, titanium dioxide and clay (RE/TiO2/Clay) were characterized and tested for the photocatalytic decomposition of formaldehyde. The results show that nanocomposite materials prepared by doping appropriate rare earth elements have better photocatalytic properties than that prepared by doping excessive rare earth elements. The photocatalytic mechanism of composite materials was studied by integrating the theory of photocatalysis with experiment results. Because the site of photocatalytic reaction was limited in the interspace of clay, photocatalytic reaction occurred by two steps: firstly, organic molecules dispersed into the interlayers of clay; secondly, organic molecules and photocatalyst of RE/TiO2 occurred photocatalytic reaction, resulting in forming carbon dioxide.展开更多
The rare earth composite ceramic materials were prepared using rare earths and far infrared natural mineral. The effects of the as-prepared ceramic materials on the oil consumption and air pollutants emissions of oil-...The rare earth composite ceramic materials were prepared using rare earths and far infrared natural mineral. The effects of the as-prepared ceramic materials on the oil consumption and air pollutants emissions of oil-burning boiler were investigated. The results show that the composite ceramic materials can radiate higher intensity of far infrared. The molecular movement is strengthened and the chemical bonds of the molecules are easily ruptured when the diesel oil is dealt with the composite materials. The oil-saving rate of the RBS·VH-1.5 boiler dealt with the rare earth composite ceramic materials is 3.49%, and the reducing rates of CO and NO in the exhaust gas are 25.4% and 9.7%, respectively.展开更多
The study on the effects of SrO/Al 2O 3 molar ratio on the crystalline phases and photoluminescence characteristics of strontium aluminate phosphors co-activated with Eu 2+ and Dy 3+ were conducted by X-ray powder dif...The study on the effects of SrO/Al 2O 3 molar ratio on the crystalline phases and photoluminescence characteristics of strontium aluminate phosphors co-activated with Eu 2+ and Dy 3+ were conducted by X-ray powder diffractometry, fluorescence spectrometer and photometer. The strontium aluminate luminescent materials with different SrO/Al 2O 3 molar ratio emit the visible lights with different color tone after removal of excitation. The peak wavelengths of the emission spectra drift in the direction of short wave, the quantity of Sr 4Al 14O 25 crystalline phase increases and the afterglow time lengthens with the SrO/Al 2O 3 reduction. The results show that when the SrO/Al 2O 3 molar ratio is near 1, the photoluminescence materials have high luminescent intensity, and when it is near 0.75, they have long afterglow time. However, when SrO/Al 2O 3 molar ratio is more than 1, the luminescent materials appear strong alkaline in water solution; when SrO/Al 2O 3 molar ratio is much less than 0.75, the samples need a higher temperature to be sintered.展开更多
Supercapacitor is an imminent potential energy storage system,and acts as a booster to the batteries and fuel cells to provide necessary power density.In the last decade,carbon and carbonaceous materials,conducting po...Supercapacitor is an imminent potential energy storage system,and acts as a booster to the batteries and fuel cells to provide necessary power density.In the last decade,carbon and carbonaceous materials,conducting polymers and transition metal oxide/hydroxide based electrode materials have been made to show a remarkable electrochemical performance.Rare-earth materials have attracted significant research attention as an electrode material for supercapacitor applications based on their physicochemical properties.In this review,rare earth metals,rare earth metal oxides/hydroxides,rare-earth metal chalcogenides,rare-earth metal/carbon composites and rare-earth metal/metal oxide composites based electrode materials are discussed for supercapacitors.We also discuss the energy chemistry of rare-earth metal-based materials.Besides the factors that affect the performance of the electrode materials,their evaluation methods and supercapacitor performances are discussed in details.Finally,the future outlook in rare-earth-based electrode materials is revealed towards its current developments for supercapacitor applications.展开更多
Some compounds of LiCo 1- x RE x O 2 (RE=rare earth elements and x =0.01～0.03) were prepared by doping rare earth elements to LiCoO 2 via solid state synthesis. The microstructure characteristics of the LiCo 1- x RE ...Some compounds of LiCo 1- x RE x O 2 (RE=rare earth elements and x =0.01～0.03) were prepared by doping rare earth elements to LiCoO 2 via solid state synthesis. The microstructure characteristics of the LiCo 1- x RE x O 2 were investigated by XRD. It was found that the lattice parameters c are increased and the lattice volumes are enlarged compared to that of LiCoO 2. Moreover, the performance of LiCo 1- x RE x O 2 as the cathode material in lithium ion battery is improved, especially LiCo 1- x Y x O 2 and LiCo 1- x La x O 2. The initial charge/discharge capacities of LiCo 0.99 Y 0.01 O 2 and LiCo 0.99 La 0.01 O 2 are 174/154 (mAh·g -1 ) and 159/149 (mAh·g -1 ) respectively, while those for LiCoO 2 working in the same way are only 139/131 (mAh·g -1 ).展开更多
Some rare earth doping spinel LiMn2-xRExO4 （RE=La, Ce, Nd） cathode materials for lithium ion batteries were synthesized by the solid-state reaction method. The structure characteristics of these produced samples wer...Some rare earth doping spinel LiMn2-xRExO4 （RE=La, Ce, Nd） cathode materials for lithium ion batteries were synthesized by the solid-state reaction method. The structure characteristics of these produced samples were investigated by XRD, SEM, and particle size distribution analysis. According to the microstructure and charge-discharge testing, the effect of doping rare earth on stabilizing the spinel structure was analyzed. Through a series of doping experiments, it is shown that when the doping content x within the range of 0.01～0.02 the cycle performance of the materials is greatly improved. The discharge capacity of the sample LiMn1.98La0.02O4, LiMn1.98Ce0.02O4 and LiMn1.98Nd0.02O4 remain 119.1, 114.2 and 117.5 mAh·g-1 after 50 cycles.展开更多
The compositions of REE in quartz and pyrite from the main stage of the Laowan gold deposit in Henan Province and that in quartz from Laowan granite were determined by inductively coupled plasma-mass-spectrometry (ICP...The compositions of REE in quartz and pyrite from the main stage of the Laowan gold deposit in Henan Province and that in quartz from Laowan granite were determined by inductively coupled plasma-mass-spectrometry (ICP-MS) to trace the source of ore-forming materials. Meanwhile, the REE compositions of the deposit ore, granite and metamorphic wall rock were also considered for comparative studies in detail. The range of ∑REE of quartz and pyrite from the deposit ores is 4.18×10 -6～30.91×10 -6, the average of ∑REE is 13.39×10 -6, and the average of ∑REE of quartz in the Laowan granite is 6.68×10 -6. There is no distinct difference of REE parameters between the deposit ore quartz and granite quartz. The quartz in gold deposit has the same REE particular parameters as quartzes from Laowan granite, such as δ_ Eu, δ_ Ce, (La/Yb)_N and (La/Sm)_N, partition degree of LREE to HREE, especially, the chondrite-normalized REE patterns, but no similarity to those from metamorphic wall rock, which shows that ore-forming hydrothermal fluid is mainly the fluid coming from the Laowan granite magma, rather than metamorphic fluid. Meanwhile, comparison studies on REE features between minerals from the deposit ores and related geological bodies in the deposit show that REE characteristics of minerals can serve as an indicator of ore-forming fluid properties and sources, while the REE characteristics of the bulk samples (such as deposit ores, granites and wall rocks) can not trace the source of the ore-forming materials exactly.展开更多
文摘Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properties of rare earth luminescent materials, with the goal of uncovering their importance in luminescence mechanisms and applications. Through theoretical calculations and experimental methods, we conducted in-depth analyses on materials composed of various rare earth elements. Regarding electronic structure, we utilized computational techniques such as density functional theory to investigate the band structure, valence state distribution, and electronic density of states of rare earth luminescent materials. The results indicate that the electronic structural differences among different rare earth elements notably influence their luminescence performance, providing crucial clues for explaining the luminescence mechanism. In terms of optical properties, we systematically examined the material’s optical behaviors through fluorescence spectroscopy, absorption spectroscopy, and other experimental approaches. We found that rare earth luminescent materials exhibit distinct absorption and emission characteristics at different wavelengths, closely related to the transition processes of their electronic energy levels. Furthermore, we studied the influence of varying doping concentrations and impurities on the material’s optical properties. Experimental outcomes reveal that appropriate doping can effectively regulate the emission intensity and wavelength, offering greater possibilities for material applications. In summary, this study comprehensively analyzed the electronic structure and optical properties of rare earth luminescent materials, providing deep insights into understanding their luminescence mechanisms and potential value in optoelectronic applications. In the future, these research findings will serve as crucial references for the technological advancement in fields such as LEDs, lasers, and bioimaging.
文摘Solid-state white LED will be a new generation of energy-saving light source in 21 century. In order to emitting white light, one of important approaches is using luminescence conversion technology with rare earth phosphors, which can be excited by the 460 nm blue light or 400 nm near violet light emitted from the InGaN chip and then emit white light. The rare earths doped phosphors prepared by us such as YAG∶Ce 3+, Ca 1-xSrxS∶Eu 2+, Ga2S3∶Eu 2+, MGa2S4∶Eu 2+（M=Ca, Sr, Ba）, SrGa 2+xS 4+y∶Eu 2+, （Ca 1-xSrx）Se∶Eu 2+, SrLaGa3S6O∶Eu 2+, （M1, M2） 10（PO4）6X2 （M1=Ca, Sr, Ba; M2=Eu, Mn; X=F, Cl, Br） and NaEu 0.92Sm 0.08（MoO4）2 were reported. They emit blue, green, yellow or red color light. Some white LEDs were made by these phosphors with blue or near violet InGaN chips and their chromaticity coordinate （x, y）, correlated color temperature TC, and color rendering index Ra are reported.
基金financial supportfrom PRAMX 98-05 and helpful discussion with Dr.A.C.Franville.
文摘Hybrid materials incorporating Eu-(TTA)3·2H20 (hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of Eu3+ under UV light exci-tation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.
文摘1 Results The size of nanoscale rare earth luminescent materials is often smaller than that of the excitement or emission wavelength,and it has amazing surface state density. Therefore,it shows a lot of new luminescent phenomena such as the shift of CTS,the broadening of emission peaks,the variation of fluorescent lifetimes and quantum efficiency,and the increase of quenching concentration.It is not only of academic interest but also of technological importance for advanced phosphor applications to rese...
文摘A new method of preparation of irradiative material by using rare earth as luminophor and inorganic powder as base nucleus was presented.Rare earth was used to make colloid, which was mixed with base nucleus solution,where deposition/attachment reaction took place and rare earth was adhered onto the surface of base nucleus, hence yielding a new rare earth encapsulated irradiative material.Fluorescent spectrum analysis shows that this material possesses two emission peaks, one within 400 ～ 500 nm and the other within 580 ～ 700 nm, reflecting the luminous characteristics of original rare earth material.
文摘Trivalent rare earth ions(Ln3+)have the unique elec-tronic configurations[Xe]4fn(n=0-14)and numerous energy levels,which endow rare earth luminescent mate-rials with many fascinating optical properties over a broad spectral region ranging from the ultraviolet(UV)to the near infrared(NIR);these include tunable atomic-like excitation/emission spectra,large Stokes/anti-Stokes shifts,long luminescent lifetimes,and excellent photostability1-4.
文摘Rare-earth doped luminescent nanomaterials are attractive and have many potential applications in health,energy,information and safety area[1].Similar to most chemical processes,the process to synthesize luminescent nanomaterials is complicated and it needs a combination of a series of unit operations including mixing of the reactants.
基金Project supported by the Key Technologies R & D Programme of Tianjin (06YFGZGX02400)
文摘Rare earth mineral composite materials were prepared using rare earths and natural far-infrared mineral materials. The influences of rare earth additive content and heat treatment temperature on the far infrared radiance were studied. The results show that the far infrared radiance of rare earth mineral composite materials is 0.93 when the rare earth additive content is 6% and heat treatment temperature is 750 ℃.
基金National Nature Science Foundation of China (50574045)Specialized Research Fund for the Doctoral Program of Higher Education (20050674003)the Science Research Fund of Yunnan Provincial Department of Education (07Y41398)
文摘The antimicrobial effect of the Ag-White Carbon Black containing rare earth was investigated. Inorganic antibiotic materials consist of the antibacterial ion, the additive and the carrier. The sol-gel method was used to prepare the white carbon black carrier. Ag+ was selected to be the antibacterial ion, and cerous nitrate was selected to be the additive. They were synthesized on the white carbon black carrier. The structures and properties of antibacterial material were characterized by inductively coupled plasma, particle size measurement instrument, fourier transform infrared and enumeration tests (Escherichia coli as experimental bacterium). Results showed that the amount of antibacterial ions and bacteriostasis rate of this new material are higher than those for the general Ag-antibacterial white carbon black (without containing rare earth). Ag+ was bound to white carbon black by ion exchange process and adsorption process. Bacteriostasis rate is over 99%, and the particle size can be extended down to 7 μm with a narrow size distribution. Other advantages of this material are good thermal and light stability. Furthermore, from the antibacterial experiment in rubber and the coating surface of metal, this new material showed promising results. The possible antibacterial mechanism was also proposed through all the experimental data in this study.
基金Project supported by the Key Technologies R & D Programme of Tianjin (06YFGZGX02400)
文摘Rare earth composite materials radiating far-infrared rays were prepared according to far infrared absorption spectrum of main component in liquefied petroleum gas (LPG). The composite materials were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transformed infrared spectra(FTIR). The results show that after the composite materials were calcined at 873 K for 4 h, FTIR spectra of rare earth composite materials display two new peaks at 1336 and 2926 cm-1 available for activating LPG.
基金the National Nature Science Foundation of China (50574045)the Specialized Research Fundfor the Doctoral Program of Higher Education (20050674003)the Science Research Fund of Yunnan Provincial Department of Education(07Y41398)
文摘Inorganic antibacterial materials consist of the antibacterial ions, the additives and the carrier. In this study, we synthesized a new inorganic antibacterialmaterial, of which Cu2+ and Ag+ were selected to be the bi-component antibacterial ions, cerous nitrate served as the additives, and the white carbon black was chosen as the carrier, which was prepared by a sol-gel method. The as-synthesized antibacterial material was characterized by inductively coupled plasma, particle size measurement instrument, scanning electron microscope and enumeration tests. The result showed that the amount of antibacterial ions and bacteriostasis rate of this new material are higher than those for the single-ion inorganic antibacterial material. In addition, the particle size of this material can be extended down to 7 μm with a narrow size distribution. Other advantages of this material are its loose and dispersive structure, good thermal and light stability. From the antibacterial experiment in rubber and the coating surface of metal, this new material showed promising results. The possible antibacterial mechanism was also proposed through all the experimental data in this study.
基金supported by Natural Science Foundation of Hebei Province(202140)
文摘The bi rare earth complexes EuTb( m MBA) 6(phen) 2·2H 2O, TbY( m MBA) 6(phen) 2·2H 2O were synthesized by the reaction of RECl 3 with m methylbenzoic acid and 1,10 phenanthroline in ethanol solution, where m MBA=m methylbenzoate and phen=1,10 phenanthroline. The luminescence properties of the title complexes were studied in comparison with the corresponding complexes Eu 2( m MBA) 6(phen) 2·2H 2O and Tb 2( m MBA) 6(phen) 2·2H 2O respectively. The results indicate that the emission intensity from europium ion can be greatly enhanced by the terbium ion, while the emission from terbium ion was strongly quenched by europium ion in EuTb( m MBA) 6(phen) 2·2H 2O; the emission intensity from terbium ion can be greatly enhanced by yttrium ion in TbY( m MBA) 6(phen) 2·2H 2O. The mechanism about the results was discussed.
基金the Natural Science Foundation of Shandong Province (Y2005F04)Jinan Young Star Plan of Science and Technology (08108)
文摘Through the addition of Y, Sm and Ce in Al2O3/(W, Ti)C ceramic matrix, it was found that the amount and kind of the added rare earth elements have some different influences on the mechanical properties and wear resistance of the composite. Under the present experimental conditions, the flank wear curves of the selected ceramic tool materials when machining the hardened tool steel obeyed the wear law well. But wear resistance of different ceramic materials varied with each other. Wear resistance of rare earth ceramic tool materials was higher than that of the corresponding materials without rare earth. Wear modes of the developed Al2O3/(W, Ti)C series rare earth ceramic tool materials were mainly flank wear and accompanied with slight crater wear.
基金Project supported by the National Science Foundation of Hebei Province China (503067)
文摘The nanocomposite materials containing rare earths, titanium dioxide and clay (RE/TiO2/Clay) were characterized and tested for the photocatalytic decomposition of formaldehyde. The results show that nanocomposite materials prepared by doping appropriate rare earth elements have better photocatalytic properties than that prepared by doping excessive rare earth elements. The photocatalytic mechanism of composite materials was studied by integrating the theory of photocatalysis with experiment results. Because the site of photocatalytic reaction was limited in the interspace of clay, photocatalytic reaction occurred by two steps: firstly, organic molecules dispersed into the interlayers of clay; secondly, organic molecules and photocatalyst of RE/TiO2 occurred photocatalytic reaction, resulting in forming carbon dioxide.
基金Project supported by the Key Technologies R & D Programme of Tianjin (06YFGZGX02400)
文摘The rare earth composite ceramic materials were prepared using rare earths and far infrared natural mineral. The effects of the as-prepared ceramic materials on the oil consumption and air pollutants emissions of oil-burning boiler were investigated. The results show that the composite ceramic materials can radiate higher intensity of far infrared. The molecular movement is strengthened and the chemical bonds of the molecules are easily ruptured when the diesel oil is dealt with the composite materials. The oil-saving rate of the RBS·VH-1.5 boiler dealt with the rare earth composite ceramic materials is 3.49%, and the reducing rates of CO and NO in the exhaust gas are 25.4% and 9.7%, respectively.
文摘The study on the effects of SrO/Al 2O 3 molar ratio on the crystalline phases and photoluminescence characteristics of strontium aluminate phosphors co-activated with Eu 2+ and Dy 3+ were conducted by X-ray powder diffractometry, fluorescence spectrometer and photometer. The strontium aluminate luminescent materials with different SrO/Al 2O 3 molar ratio emit the visible lights with different color tone after removal of excitation. The peak wavelengths of the emission spectra drift in the direction of short wave, the quantity of Sr 4Al 14O 25 crystalline phase increases and the afterglow time lengthens with the SrO/Al 2O 3 reduction. The results show that when the SrO/Al 2O 3 molar ratio is near 1, the photoluminescence materials have high luminescent intensity, and when it is near 0.75, they have long afterglow time. However, when SrO/Al 2O 3 molar ratio is more than 1, the luminescent materials appear strong alkaline in water solution; when SrO/Al 2O 3 molar ratio is much less than 0.75, the samples need a higher temperature to be sintered.
基金the funding for this project through the National Nature Science Foundations of China(Grant No.51873083)the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(No.sklpme2018-4-27)+1 种基金Key University Science Research Project of Jiangsu Province(18KJA130001)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX18_0759,SJCX19_0584)。
文摘Supercapacitor is an imminent potential energy storage system,and acts as a booster to the batteries and fuel cells to provide necessary power density.In the last decade,carbon and carbonaceous materials,conducting polymers and transition metal oxide/hydroxide based electrode materials have been made to show a remarkable electrochemical performance.Rare-earth materials have attracted significant research attention as an electrode material for supercapacitor applications based on their physicochemical properties.In this review,rare earth metals,rare earth metal oxides/hydroxides,rare-earth metal chalcogenides,rare-earth metal/carbon composites and rare-earth metal/metal oxide composites based electrode materials are discussed for supercapacitors.We also discuss the energy chemistry of rare-earth metal-based materials.Besides the factors that affect the performance of the electrode materials,their evaluation methods and supercapacitor performances are discussed in details.Finally,the future outlook in rare-earth-based electrode materials is revealed towards its current developments for supercapacitor applications.
文摘Some compounds of LiCo 1- x RE x O 2 (RE=rare earth elements and x =0.01～0.03) were prepared by doping rare earth elements to LiCoO 2 via solid state synthesis. The microstructure characteristics of the LiCo 1- x RE x O 2 were investigated by XRD. It was found that the lattice parameters c are increased and the lattice volumes are enlarged compared to that of LiCoO 2. Moreover, the performance of LiCo 1- x RE x O 2 as the cathode material in lithium ion battery is improved, especially LiCo 1- x Y x O 2 and LiCo 1- x La x O 2. The initial charge/discharge capacities of LiCo 0.99 Y 0.01 O 2 and LiCo 0.99 La 0.01 O 2 are 174/154 (mAh·g -1 ) and 159/149 (mAh·g -1 ) respectively, while those for LiCoO 2 working in the same way are only 139/131 (mAh·g -1 ).
基金Project supported by the National Natural Science Foundation of China (20273047)
文摘Some rare earth doping spinel LiMn2-xRExO4 （RE=La, Ce, Nd） cathode materials for lithium ion batteries were synthesized by the solid-state reaction method. The structure characteristics of these produced samples were investigated by XRD, SEM, and particle size distribution analysis. According to the microstructure and charge-discharge testing, the effect of doping rare earth on stabilizing the spinel structure was analyzed. Through a series of doping experiments, it is shown that when the doping content x within the range of 0.01～0.02 the cycle performance of the materials is greatly improved. The discharge capacity of the sample LiMn1.98La0.02O4, LiMn1.98Ce0.02O4 and LiMn1.98Nd0.02O4 remain 119.1, 114.2 and 117.5 mAh·g-1 after 50 cycles.
文摘The compositions of REE in quartz and pyrite from the main stage of the Laowan gold deposit in Henan Province and that in quartz from Laowan granite were determined by inductively coupled plasma-mass-spectrometry (ICP-MS) to trace the source of ore-forming materials. Meanwhile, the REE compositions of the deposit ore, granite and metamorphic wall rock were also considered for comparative studies in detail. The range of ∑REE of quartz and pyrite from the deposit ores is 4.18×10 -6～30.91×10 -6, the average of ∑REE is 13.39×10 -6, and the average of ∑REE of quartz in the Laowan granite is 6.68×10 -6. There is no distinct difference of REE parameters between the deposit ore quartz and granite quartz. The quartz in gold deposit has the same REE particular parameters as quartzes from Laowan granite, such as δ_ Eu, δ_ Ce, (La/Yb)_N and (La/Sm)_N, partition degree of LREE to HREE, especially, the chondrite-normalized REE patterns, but no similarity to those from metamorphic wall rock, which shows that ore-forming hydrothermal fluid is mainly the fluid coming from the Laowan granite magma, rather than metamorphic fluid. Meanwhile, comparison studies on REE features between minerals from the deposit ores and related geological bodies in the deposit show that REE characteristics of minerals can serve as an indicator of ore-forming fluid properties and sources, while the REE characteristics of the bulk samples (such as deposit ores, granites and wall rocks) can not trace the source of the ore-forming materials exactly.
