Two isomorphous 2D zigzag-ladder structure coordination polymers containing coordination supramolecular capsules are reported,which are built by trivalent lanthanide ions,pyridine N-oxide(PNO) and p-sulfonatothiacal...Two isomorphous 2D zigzag-ladder structure coordination polymers containing coordination supramolecular capsules are reported,which are built by trivalent lanthanide ions,pyridine N-oxide(PNO) and p-sulfonatothiacalix[4]arene(H4TCAS4-):[Ln2(PNO)2(H2O)10?(H2TCAS)2].[Ln2(H2TCAS)2(H2O)6(MeOH)2].2MeOH.12H2O(Ln = La,1;Nd,2).Crystal data for complex 1:C31H51La2NO33S8,Mr = 1500.03,triclinic system,P 1 space group,with a = 11.732(2),b = 15.007(3),c = 15.262(3),α = 78.05(3),β = 80.77(3),γ = 83.89(3)°,Z = 2,V = 2587.3(9)3,Dc = 1.925 g/cm3,μ = 2.051 mm-1,F(000) = 1500,the final R = 0.0300 and wR = 0.0823;and those for complex 2:C31H51Nd2NO33S8,Mr = 1510.69,triclinic system,P1 space group,with a = 11.719(2),b = 14.941(3),c = 15.157(3),α = 78.03(3),β = 80.84(3),γ = 83.95(3)°,Z = 2,V = 2555.9(9)3,Dc = 1.963 g/cm3,μ = 2.436 mm-1,F(000) = 1512,the final R = 0.0493 and wR = 0.1267.There are two coordination environments of lanthanide ions.One is bridged by two PNO molecules forming a dimeric Ln ion in the O,O’-μ2 mode.The dinuclear ions are shrouded by two H2TCAS6-ions through coordination interactions and hydrogen bonds.The other coordination mode of Ln ions is a zigzag 1D chain linked by up-down H2TCAS6-ions.By the coordination capsules,the complexes form 2D zigzag-ladder structure coordination polymers.展开更多
Four kinds of lanthanide ions(Sm^3+,Yb^3+,Eu^3+,La^3+)as an additive were added into the aqueous solution containing methanol,respectively,and their effects on methanol elecotrooxidation in aqueous solutions wer...Four kinds of lanthanide ions(Sm^3+,Yb^3+,Eu^3+,La^3+)as an additive were added into the aqueous solution containing methanol,respectively,and their effects on methanol elecotrooxidation in aqueous solutions were studied with cyclic voltammetry.The results show that the four kinds of ions have promotion action upon the electrooxidation of methanol to different degrees.The best additive,Sm^3+,can increase the anodic oxidation current of methanol by 80%and the peak potential shifted negatively about 50 mV.The promotion effects of the lanthanide ions were considered to be related to the extranuclear electron distribution of these ions and their adsorption on the Pt electrode surface.展开更多
A mixture containing eleven lanthanide ions was separated and detected on an anion exchange co lumn by ion chromatography with indirect photometry detection (IPC).An aqueous solution of 1.5×10 -2 mol/L ni...A mixture containing eleven lanthanide ions was separated and detected on an anion exchange co lumn by ion chromatography with indirect photometry detection (IPC).An aqueous solution of 1.5×10 -2 mol/L nitrilotri(methylenephosphonic) acid and 2.5×10 -3 mol/L tiron was used as the eluent in which the former served as complexing agent and eluent,the latter played as color reagent and eluent.The effects of acidity,concentration and composition of eluent on the retention behavior of the analytes and detection sensitivity are discussed.展开更多
The toxicity of lead ions has become the severe challenge for the all-inorganic lead halide p erovskite materials,although some works have rep orted the lead-free perovskite nanocrystals(NCs),the photoluminescence qua...The toxicity of lead ions has become the severe challenge for the all-inorganic lead halide p erovskite materials,although some works have rep orted the lead-free perovskite nanocrystals(NCs),the photoluminescence quantum yield(PLQY)of these materials is still unsatisfactory.Meanwhile,because the halogen ions can be easily exchanged,the controllable multicolor emission in perovskite NCs is difficult to realize in current reports.In this work,we introduced lanthanide ions into lead-free Cs_(3)Sb_(2)Cl_(9) perovskite NCs.Benefitting from the energy transfer between Cs_(3)Sb_(2)Cl_(9) perovskite NC host and lanthanide ions,the multicolor emission was realized.Based on controlling the doping concentration of Tb6(3+)and Eu~(3+)ions,the white light emission under UV excitation would be turned easily in the Tb6(3+)/Eu~(3+)codoped NCs.In addition,efficient energy transfer from perovskite NCs to Tb6(3+)or Eu~(3+)ions is beneficial to improving the optical properties of lead-free perovskite NCs,resulting in maximum PLQYs of red,green and white light emission of 22.6%,19.7%and 28.5%,respectively.Finally,a white light emitting device(WLED)was fabricated with a power efficiency of 18.5 lm/W,which presents the Commission Internationale de l'Eclairage(CIE)of(0.33,0.35).展开更多
Sorption of lanthanum(Ⅲ), cerium(Ⅲ and neodymium(Ⅲ) ions from the aqueous solutions of mixtures through adsorption on the biochar composites was investigated as a function of sorbent mass, pH, phase contact ti...Sorption of lanthanum(Ⅲ), cerium(Ⅲ and neodymium(Ⅲ) ions from the aqueous solutions of mixtures through adsorption on the biochar composites was investigated as a function of sorbent mass, pH, phase contact time and initial concentration of solutions at 295 K. The maximum removal of lanthanide ions takes place under the following conditions: 0.1 g of sorbent mass, pH 4 and 360 rain contact time for all studied initial concentrations of solutions. Kinetics of La(Ⅲ), Ce(Ⅲ) and Nd(Ⅲ) ions sorption proceeded by a fast initial uptake reached equilibrium. This process was modelled by means of the pseudo first order, pseudo second order, intraparticle diffusion and Elovich models. The desorption of three lanthahide ions by nitric, hydrochloric and sulfuric acids at a concentration of 1 mol/L from biochar composites was also studied. In order to investigate the sorption mechanism FFIR, XRD and XPS analyses were performed after sorption of ions from the mixture.展开更多
The luminescence from lanthanide ions has potential applications in light emitting diodes,biomedical,solar cells,sensors,display,etc.However,the luminescence is suffered from the various problems,such as low luminesce...The luminescence from lanthanide ions has potential applications in light emitting diodes,biomedical,solar cells,sensors,display,etc.However,the luminescence is suffered from the various problems,such as low luminescence efficiency and inharmonious wavelength for energy transfer.Magnetic field is an efficient method to modulate the wavelength and intensity of luminescence from lanthanide ions.Magnetic field redistributes the populated electrons in the excited states to tune the wavelength of lanthanide ions by Zeeman effect,mixing effect,and quantum confinement effect.Magnetic field enhances or suppresses the luminescence intensity by the administration of cross-relaxation,energy transfer,and Boltzmann population.In this review,we first introduce the various phenomena and mechanisms of magnetic field modulated downshift luminescence from lanthanide ions,including Zeeman effect,cross-relaxation,crystal structure,absorption,quantum confinement effect,and magneticoptical hysteresis.Then,we explain the regulation of upconversion luminescence by magnetic field,containing energy transfer and mixing effect.Finally,different options regarding how to understand the mechanism of magnetic field-modulated luminescence from lanthanide ions in the future are outlined.展开更多
Two new coordination polymers,[Ln(oba)(ox)0.5(H2O)2]n(Ln = Ho(1),Eu(2);H2oba = 4,4?-oxybis(benzoic acid),H2ox = oxalic acid) have been synthesized under hydrothermal conditions.According to single-cryst...Two new coordination polymers,[Ln(oba)(ox)0.5(H2O)2]n(Ln = Ho(1),Eu(2);H2oba = 4,4?-oxybis(benzoic acid),H2ox = oxalic acid) have been synthesized under hydrothermal conditions.According to single-crystal X-ray diffraction analyses,complex 1 crystallizes in the monoclinic system,space group P21/c with a = 13.783(2),b =10.0120(15),c = 12.1974(18) ,β = 105.217(2)°,V = 1624.2(4) 3,C15H12O9Ho,Mr = 501.18,Z = 4,Dc = 2.050 g/cm3,F(000) = 964,μ = 4.919 mm-1,λ(MoKα) = 0.71073 ?,GOOF = 1.124,the final R = 0.0239 and wR = 0.0570 for 3310 independent reflections with Rint = 0.0298.Complexes 2 and 1 are isostructural.Oba and ox ligands bridge the Ln(III) ions into 2D layers with(4,4) topology,which are further interlinked into a 3D supramolecular network by hydrogen bonds.TG curves of the two complexes are studied to examine their thermal stabilities.Additionally,complex 2 shows red fluorescence in the solid state at room temperature.展开更多
Based on the completely parametric crystal-field model, the energy level parameters, including free-ion parameters and crystal-field parameters, obtained by fitting the experimental energy level data sets of Ln^(3+...Based on the completely parametric crystal-field model, the energy level parameters, including free-ion parameters and crystal-field parameters, obtained by fitting the experimental energy level data sets of Ln^(3+) in LiYF_4 were systematically analyzed. The results revealed that the regular variation trends of the major parameters at relatively low site symmetry still existed. The g factors of ground states were calculated using the parameters obtained from least-squares fitting. The results for Ce^(3+), Nd^(3+), Sm^(3+), Dy^(3+) and Yb^(3+) were in good agreement with experiment, while those of Er^(3+) deviated from experiment dramatically. Further study showed that the g factors depended strongly on B_4~6, and a slightly different B_4~6 value of -580cm^(-1) led to g factors agreeing well with the experimental values.展开更多
The structure of phenylalanine transfer ribonucleic acid(tRNA Phe ) in solution was explored by 1 H NMR spectroscopy to evaluate the effect of lanthanide ion on the structural and conformational change. It w...The structure of phenylalanine transfer ribonucleic acid(tRNA Phe ) in solution was explored by 1 H NMR spectroscopy to evaluate the effect of lanthanide ion on the structural and conformational change. It was found that La 3+ ions possess specific effects on the imino proton region of the 1 H NMR spectra for yeast tRNA Phe . The dependence of the imino proton spectra of yeast tRNA Phe as a function of La 3+ concentration was examined, and the results suggest that the tertiary base pair G 15 ·C 48 , which is located in the terminal in the augmented dihydrouridine helix(D helix), was markedly affected by La 3+ (shifted to downfield by as much as 0 35). Base pair U 8·A 14 in yeast tRNA Phe , which are stacked on G 15 ·C 48 , was also affected by added La 3+ when 1~2 Mg 2+ were also present. Another imino proton that may be affected by La 3+ in yeast tRNA Phe is that of the tertiary base pair G 19 ·C 56 . The assignment of this resonance in yeast tRNA Phe is tentative since it is located in the region of highly overlapping resonances beween 12 6 and 12 2. This base pair helps to anchor the D loop to the TΨC loop. The binding of La 3+ caused conformational change of tRNA, which is responsible for shifts to upfield or downfield in 1 H NMR spectra.展开更多
Experimental data of hydrolytic polymerization of lanthanide ions in aqueous solution were treated by graphic method,computer fitting and pq analysis,species present were ascertained and hydrolysis constants obtained....Experimental data of hydrolytic polymerization of lanthanide ions in aqueous solution were treated by graphic method,computer fitting and pq analysis,species present were ascertained and hydrolysis constants obtained.Ln(OH)^(2+)and Ln_2(OH)_2^(4+)predominated in the species of all hydroly- sis products.When the first and the second hydrolysis constants were plotted against radii and ef- fective nuclear charge of lanthanide ions,the curves obtained conformed with the“three-division groups”rule.Correlation between hydrolysis constants of Ln_2(OH)_2^(4+)and other hydrolysis constants is linear. Using the above empirical correlations we calculated hydrolysis constants of all lanthanide ions and obtained satisfactory results which showed good regularity for hydrolysis of lanthanide ions and thus systematized all data of the reaction.展开更多
Luminescence quench is common in overdoped upconversion nanoparticles.Various methods have been proposed to counteract the adverse effects of concentration quenching on luminescence,but in upconversion nanoparticles t...Luminescence quench is common in overdoped upconversion nanoparticles.Various methods have been proposed to counteract the adverse effects of concentration quenching on luminescence,but in upconversion nanoparticles that are highly doped with both sensitizers and activators,the factors that contribute to the diminishing of the emission cannot be summarized by a single cause.Herein,a core-shell design is used to spatially separate the sensitizer(Yb^(3+))and activator(Er^(3+))and to modulate the emission by changes in the distribution position as well as the concentration of the dopant ions in order to probe the factors affecting the luminescence.When the sensitizer ions are located in the core,the luminescence intensity of the nanoparticles is significantly weaker than that of the other distribution,which implies that the effect of sensitizer and activator on luminescence in the highly doped state has a different and more complex mechanism.The intensity of the emission is more affected by Yb^(3+)than Er^(3+),which includes not only the self-quenching of Yb^(3+),but also the dominance in the Yb^(3+)-Er^(3+)cross-relaxation.In this finding may provide new ideas for revealing the reasons for the diminished luminescence of highly doped upconversion nanoparticles and thus for enhancing luminescence.展开更多
The doping effects of La^3+, Gd^3+ and Lu^3+ on the crystal structure and luminescence properties of (Yo96-x LnxCe0.04)3Al5O12(Ln = Gd, La, Lu) phosphors were studied. The X-ray diffraction patterns presented t...The doping effects of La^3+, Gd^3+ and Lu^3+ on the crystal structure and luminescence properties of (Yo96-x LnxCe0.04)3Al5O12(Ln = Gd, La, Lu) phosphors were studied. The X-ray diffraction patterns presented that with the inerease of the doping concentrations of La^3+ and Gd^3+ ions, the d-value of (Y0.96-xLnxCe0.04)3Al5O12 (Ln = Gd, La) inereased and the larger the doping ion, the stronger the effect would be. The doping amount causing phase transition in (Y0.96-xLnxCe0.04)3Al5O12 decreased with the inerease of the ionic radii of the doping lanthanide ions (La^3+: 0.106 nm, Gd^3+: 0. 094 nm, Lu^3+ : 0.083 nm). The bigger doping ion of Gd^3+ made the emission of (Y0.96-xGdxCe0.04)3Al5O12 move to red spectral region, but the smaller one of Lu^3+ made it blue.展开更多
In this paper,we report for the first time the controlled synthesis of lanthanide ion(Ln3+)-doped tetragonal-phase Na3Zr F7nanocrystals(NCs)via a high-temperature co-precipitation approach.The as-synthesized Na3Zr F7N...In this paper,we report for the first time the controlled synthesis of lanthanide ion(Ln3+)-doped tetragonal-phase Na3Zr F7nanocrystals(NCs)via a high-temperature co-precipitation approach.The as-synthesized Na3Zr F7NCs are systematically studied by utilizing the XRD,TEM as well as high-resolution photoluminescence(PL)spectroscopy.The morphology and size for the as-synthesized Na3Zr F7NCs can be finely controlled by changing the experimental parameters such as the amount of precursor,solvent ratio,reaction temperature and time.By utilizing the red-emitting Eu3+ion as an efficient optical/structural probe,the successful hetero-valence doping of Ln3+activators in the lattices of Na3Zr F7NCs is well-established regardless of their different valences and radii between host Zr4+ion and Ln3+dopant.As a result,intense upconversion(UC)luminescence(UCL)ranging from UV to visible and to NIR spectral regions can be readily achieved after the doping of typical UCL couples of Yb3+/Er3+,Yb3+/Tm3+and Yb3+/Ho3+into the lattices of Na3Zr F7NCs when excited by using a 980-nm NIR diode laser.展开更多
The interaction of trivalent lanthanide ions and divalent calcium ions with sph-'ngomyelm bilayer has been studied by FT-Raman spectroscopy.The results showed that the bonding of metal ions to the phosphate group ...The interaction of trivalent lanthanide ions and divalent calcium ions with sph-'ngomyelm bilayer has been studied by FT-Raman spectroscopy.The results showed that the bonding of metal ions to the phosphate group of sphingomyelin bi-iayer,either La3+or Ca2+did not change the conformation of the choline group,that is,O-C-C-N+is still in its gauche conformation.The presence of metal ions changed the states of the interfacial region from liquid-like to amorphous state and even to crystalline.They increased the fluidity of acyl chains of sphingomyelin bilaver and made them packed disorderly.展开更多
Five lanthanide porphyrin complexes with 5- (4-nitrophenyl) -10, 15, 20-triphenylporphyrin and acetylacetonate ligands were synthesized and characterized by elemental analysis, IRspectra, Uv-visible spectra, IH NMR. T...Five lanthanide porphyrin complexes with 5- (4-nitrophenyl) -10, 15, 20-triphenylporphyrin and acetylacetonate ligands were synthesized and characterized by elemental analysis, IRspectra, Uv-visible spectra, IH NMR. The structures of the complexes were proposed.展开更多
In this paper,a series of GdOF-based green phosphors doped with Ho^(3+) and Yb^(3+) ions was prepared by a simple co-precipitation method.The crystal structure s and optical prope rties were investigated in detail.The...In this paper,a series of GdOF-based green phosphors doped with Ho^(3+) and Yb^(3+) ions was prepared by a simple co-precipitation method.The crystal structure s and optical prope rties were investigated in detail.The intensity of the emission of GdOF:Yb^(3+),Ho^(3+) phosphors is enhanced by the effective energy transfer from Yb^(3+) to Ho^(3+),and the optimal luminescence is achieved with the Ho^(3+)doping amount of 0.1 mol%as well as Yb^(3+) doping amount of 5 mol%.Tunable UC emission of samples is achieved by adjusting the doping concentration of Ho^(3+) or Yb^(3+).The purity of the green UC emission is further improved by enhancing the excitation pumping power.In addition,logarithmic functions of green,red and nearinfrared radiation intensities were calculated versus logarithmic function of pump power for further study.A possible UC luminescence mechanism between Yb^(3+) and Ho^(3+) is discussed based on powerdependent UC luminescence spectrum and decay lifetimes.These results suggest that GdOF:Yb^(3+),Ho^(3+)phosphors with bright and high-purity green UC emission have potential applications in the fields of bioimaging,display and illumination.展开更多
Compared with the conventional first near-infrared(NIR-I,700900 nm)window,the short-wave infrared region(SWIR,900—1700nm)possesses the merits of the increasing tissue penetration depths and the suppression of scatter...Compared with the conventional first near-infrared(NIR-I,700900 nm)window,the short-wave infrared region(SWIR,900—1700nm)possesses the merits of the increasing tissue penetration depths and the suppression of scattering background,leading to great potential for in vivo imaging.Based on the limitations of the common spectral domain,and the superiority of the time-dimension,time-resolved imaging eliminates the auto-fuorescence in the biological tissue,thus supporting higher signal-to-noise ratio and sensitivities.The imaging technique is not affected by the difference in tissue composition or thickness and has the practical value of quan-titative in vivo detection.Almost all the relevant time-resolved imaging was carried out around lanthanide-doped upconversion nanomaterials,owing to the advantages of ultralong luminescence lifetime,excellent photostability,controllable morphology,easy surface modification and various strategies of regulating lifetime.Therefore,this review presents the research progress of SWIR time-resolved imaging technology based on nanomaterials doped with lanthanide ions as luminescence centers in recent years.展开更多
A series of c arbosilane dendrimers with acetyl end-group were synthesized. Their structures were characterized by 1H NMR, IR, and MS, respectively. Then dendrimers were coordinated with lanthanide ions (Eu3+ and Tb...A series of c arbosilane dendrimers with acetyl end-group were synthesized. Their structures were characterized by 1H NMR, IR, and MS, respectively. Then dendrimers were coordinated with lanthanide ions (Eu3+ and Tb3+, respectively). The luminescence spectra of the complexes show narrow-width emissions in visible light region. 2009 Sheng Yu Feng. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Luminescent nanothermometry can precisely and remotely measure the internal temperature of objects at nanoscale precision,which,therefore,has been placed at the forefront of scientific attention.In particular,due to t...Luminescent nanothermometry can precisely and remotely measure the internal temperature of objects at nanoscale precision,which,therefore,has been placed at the forefront of scientific attention.In particular,due to the high photochemical stability,low toxicity,rich working mechanisms,and superior thermometric performance,lanthanide-based ratiometric luminesencent thermometers are finding prevalent uses in integrated electronics and optoelectronics,property analysis of in-situ tracking,biomedical diagnosis and therapy,and wearable e-health monitoring.Despite recent progresses,it remains debate in terms of the underlying temperature-sensing mechanisms,the quantitative characterization of performance,and the reliability of temperature readouts.In this review,we show the origin of thermal response luminescence,rationalize the ratiometric scheme or thermometric mechanisms,delve into the problems in the characterization of thermometric performance,discuss the universal rules for the quantitative comparison,and showcase the cutting-edge design and emerging applications of lanthanide-based ratiometric thermometers.Finally,we cast a look at the challenges and emerging opportunities for further advances in this field.展开更多
文摘Two isomorphous 2D zigzag-ladder structure coordination polymers containing coordination supramolecular capsules are reported,which are built by trivalent lanthanide ions,pyridine N-oxide(PNO) and p-sulfonatothiacalix[4]arene(H4TCAS4-):[Ln2(PNO)2(H2O)10?(H2TCAS)2].[Ln2(H2TCAS)2(H2O)6(MeOH)2].2MeOH.12H2O(Ln = La,1;Nd,2).Crystal data for complex 1:C31H51La2NO33S8,Mr = 1500.03,triclinic system,P 1 space group,with a = 11.732(2),b = 15.007(3),c = 15.262(3),α = 78.05(3),β = 80.77(3),γ = 83.89(3)°,Z = 2,V = 2587.3(9)3,Dc = 1.925 g/cm3,μ = 2.051 mm-1,F(000) = 1500,the final R = 0.0300 and wR = 0.0823;and those for complex 2:C31H51Nd2NO33S8,Mr = 1510.69,triclinic system,P1 space group,with a = 11.719(2),b = 14.941(3),c = 15.157(3),α = 78.03(3),β = 80.84(3),γ = 83.95(3)°,Z = 2,V = 2555.9(9)3,Dc = 1.963 g/cm3,μ = 2.436 mm-1,F(000) = 1512,the final R = 0.0493 and wR = 0.1267.There are two coordination environments of lanthanide ions.One is bridged by two PNO molecules forming a dimeric Ln ion in the O,O’-μ2 mode.The dinuclear ions are shrouded by two H2TCAS6-ions through coordination interactions and hydrogen bonds.The other coordination mode of Ln ions is a zigzag 1D chain linked by up-down H2TCAS6-ions.By the coordination capsules,the complexes form 2D zigzag-ladder structure coordination polymers.
基金the National High-tech Research and Development Program of China(No.2002AA233051)the NationalNatural Science Foundation of China(No.20373019).
文摘Four kinds of lanthanide ions(Sm^3+,Yb^3+,Eu^3+,La^3+)as an additive were added into the aqueous solution containing methanol,respectively,and their effects on methanol elecotrooxidation in aqueous solutions were studied with cyclic voltammetry.The results show that the four kinds of ions have promotion action upon the electrooxidation of methanol to different degrees.The best additive,Sm^3+,can increase the anodic oxidation current of methanol by 80%and the peak potential shifted negatively about 50 mV.The promotion effects of the lanthanide ions were considered to be related to the extranuclear electron distribution of these ions and their adsorption on the Pt electrode surface.
文摘A mixture containing eleven lanthanide ions was separated and detected on an anion exchange co lumn by ion chromatography with indirect photometry detection (IPC).An aqueous solution of 1.5×10 -2 mol/L nitrilotri(methylenephosphonic) acid and 2.5×10 -3 mol/L tiron was used as the eluent in which the former served as complexing agent and eluent,the latter played as color reagent and eluent.The effects of acidity,concentration and composition of eluent on the retention behavior of the analytes and detection sensitivity are discussed.
基金Project supported by the National Natural Science Foundation of China(U21A2068,11974142,11874181,12204248)the Fundamental Research Funds for the Central UniversitiesJiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB399)。
文摘The toxicity of lead ions has become the severe challenge for the all-inorganic lead halide p erovskite materials,although some works have rep orted the lead-free perovskite nanocrystals(NCs),the photoluminescence quantum yield(PLQY)of these materials is still unsatisfactory.Meanwhile,because the halogen ions can be easily exchanged,the controllable multicolor emission in perovskite NCs is difficult to realize in current reports.In this work,we introduced lanthanide ions into lead-free Cs_(3)Sb_(2)Cl_(9) perovskite NCs.Benefitting from the energy transfer between Cs_(3)Sb_(2)Cl_(9) perovskite NC host and lanthanide ions,the multicolor emission was realized.Based on controlling the doping concentration of Tb6(3+)and Eu~(3+)ions,the white light emission under UV excitation would be turned easily in the Tb6(3+)/Eu~(3+)codoped NCs.In addition,efficient energy transfer from perovskite NCs to Tb6(3+)or Eu~(3+)ions is beneficial to improving the optical properties of lead-free perovskite NCs,resulting in maximum PLQYs of red,green and white light emission of 22.6%,19.7%and 28.5%,respectively.Finally,a white light emitting device(WLED)was fabricated with a power efficiency of 18.5 lm/W,which presents the Commission Internationale de l'Eclairage(CIE)of(0.33,0.35).
文摘Sorption of lanthanum(Ⅲ), cerium(Ⅲ and neodymium(Ⅲ) ions from the aqueous solutions of mixtures through adsorption on the biochar composites was investigated as a function of sorbent mass, pH, phase contact time and initial concentration of solutions at 295 K. The maximum removal of lanthanide ions takes place under the following conditions: 0.1 g of sorbent mass, pH 4 and 360 rain contact time for all studied initial concentrations of solutions. Kinetics of La(Ⅲ), Ce(Ⅲ) and Nd(Ⅲ) ions sorption proceeded by a fast initial uptake reached equilibrium. This process was modelled by means of the pseudo first order, pseudo second order, intraparticle diffusion and Elovich models. The desorption of three lanthahide ions by nitric, hydrochloric and sulfuric acids at a concentration of 1 mol/L from biochar composites was also studied. In order to investigate the sorption mechanism FFIR, XRD and XPS analyses were performed after sorption of ions from the mixture.
基金financially supported by National Natural Science Foundation of China(No.11704081)Guangxi Natural Science Foundation(No.2017GXNSFBA198229)+2 种基金the Scientific Research Project for Higher Education of Guangxi Zhuang Autonomous Region(No.XBZ170336)the Doctoral Scientific Research Foundation of Guangxi University(No.BRP180253)The Improvement of Basic Ability for Youth Teachers in Guangxi Education Authority(No.2017KY0020)。
文摘The luminescence from lanthanide ions has potential applications in light emitting diodes,biomedical,solar cells,sensors,display,etc.However,the luminescence is suffered from the various problems,such as low luminescence efficiency and inharmonious wavelength for energy transfer.Magnetic field is an efficient method to modulate the wavelength and intensity of luminescence from lanthanide ions.Magnetic field redistributes the populated electrons in the excited states to tune the wavelength of lanthanide ions by Zeeman effect,mixing effect,and quantum confinement effect.Magnetic field enhances or suppresses the luminescence intensity by the administration of cross-relaxation,energy transfer,and Boltzmann population.In this review,we first introduce the various phenomena and mechanisms of magnetic field modulated downshift luminescence from lanthanide ions,including Zeeman effect,cross-relaxation,crystal structure,absorption,quantum confinement effect,and magneticoptical hysteresis.Then,we explain the regulation of upconversion luminescence by magnetic field,containing energy transfer and mixing effect.Finally,different options regarding how to understand the mechanism of magnetic field-modulated luminescence from lanthanide ions in the future are outlined.
基金Supported by the National Natural Science Foundation of China (20971015,20876157)Fundamental Research Funds for the Central Universities (FRF-BR-10-002A)
文摘Two new coordination polymers,[Ln(oba)(ox)0.5(H2O)2]n(Ln = Ho(1),Eu(2);H2oba = 4,4?-oxybis(benzoic acid),H2ox = oxalic acid) have been synthesized under hydrothermal conditions.According to single-crystal X-ray diffraction analyses,complex 1 crystallizes in the monoclinic system,space group P21/c with a = 13.783(2),b =10.0120(15),c = 12.1974(18) ,β = 105.217(2)°,V = 1624.2(4) 3,C15H12O9Ho,Mr = 501.18,Z = 4,Dc = 2.050 g/cm3,F(000) = 964,μ = 4.919 mm-1,λ(MoKα) = 0.71073 ?,GOOF = 1.124,the final R = 0.0239 and wR = 0.0570 for 3310 independent reflections with Rint = 0.0298.Complexes 2 and 1 are isostructural.Oba and ox ligands bridge the Ln(III) ions into 2D layers with(4,4) topology,which are further interlinked into a 3D supramolecular network by hydrogen bonds.TG curves of the two complexes are studied to examine their thermal stabilities.Additionally,complex 2 shows red fluorescence in the solid state at room temperature.
基金Project supported by the National Key Basic Research Program of China(2013CB921800)the National Natural Science Foundation of China(11274299,11374291,11574298,11204292,11404321)the Anhui Provincial Natural Science Foundation(1308085QE75)
文摘Based on the completely parametric crystal-field model, the energy level parameters, including free-ion parameters and crystal-field parameters, obtained by fitting the experimental energy level data sets of Ln^(3+) in LiYF_4 were systematically analyzed. The results revealed that the regular variation trends of the major parameters at relatively low site symmetry still existed. The g factors of ground states were calculated using the parameters obtained from least-squares fitting. The results for Ce^(3+), Nd^(3+), Sm^(3+), Dy^(3+) and Yb^(3+) were in good agreement with experiment, while those of Er^(3+) deviated from experiment dramatically. Further study showed that the g factors depended strongly on B_4~6, and a slightly different B_4~6 value of -580cm^(-1) led to g factors agreeing well with the experimental values.
文摘The structure of phenylalanine transfer ribonucleic acid(tRNA Phe ) in solution was explored by 1 H NMR spectroscopy to evaluate the effect of lanthanide ion on the structural and conformational change. It was found that La 3+ ions possess specific effects on the imino proton region of the 1 H NMR spectra for yeast tRNA Phe . The dependence of the imino proton spectra of yeast tRNA Phe as a function of La 3+ concentration was examined, and the results suggest that the tertiary base pair G 15 ·C 48 , which is located in the terminal in the augmented dihydrouridine helix(D helix), was markedly affected by La 3+ (shifted to downfield by as much as 0 35). Base pair U 8·A 14 in yeast tRNA Phe , which are stacked on G 15 ·C 48 , was also affected by added La 3+ when 1~2 Mg 2+ were also present. Another imino proton that may be affected by La 3+ in yeast tRNA Phe is that of the tertiary base pair G 19 ·C 56 . The assignment of this resonance in yeast tRNA Phe is tentative since it is located in the region of highly overlapping resonances beween 12 6 and 12 2. This base pair helps to anchor the D loop to the TΨC loop. The binding of La 3+ caused conformational change of tRNA, which is responsible for shifts to upfield or downfield in 1 H NMR spectra.
基金This work was supported by the National Natural Science Foundat ion of China.
文摘Experimental data of hydrolytic polymerization of lanthanide ions in aqueous solution were treated by graphic method,computer fitting and pq analysis,species present were ascertained and hydrolysis constants obtained.Ln(OH)^(2+)and Ln_2(OH)_2^(4+)predominated in the species of all hydroly- sis products.When the first and the second hydrolysis constants were plotted against radii and ef- fective nuclear charge of lanthanide ions,the curves obtained conformed with the“three-division groups”rule.Correlation between hydrolysis constants of Ln_2(OH)_2^(4+)and other hydrolysis constants is linear. Using the above empirical correlations we calculated hydrolysis constants of all lanthanide ions and obtained satisfactory results which showed good regularity for hydrolysis of lanthanide ions and thus systematized all data of the reaction.
基金support from the National Natural Science Foundation of China(No.22275120)the Science and Technology Commission of Shanghai Municipality(No.22520711600).
文摘Luminescence quench is common in overdoped upconversion nanoparticles.Various methods have been proposed to counteract the adverse effects of concentration quenching on luminescence,but in upconversion nanoparticles that are highly doped with both sensitizers and activators,the factors that contribute to the diminishing of the emission cannot be summarized by a single cause.Herein,a core-shell design is used to spatially separate the sensitizer(Yb^(3+))and activator(Er^(3+))and to modulate the emission by changes in the distribution position as well as the concentration of the dopant ions in order to probe the factors affecting the luminescence.When the sensitizer ions are located in the core,the luminescence intensity of the nanoparticles is significantly weaker than that of the other distribution,which implies that the effect of sensitizer and activator on luminescence in the highly doped state has a different and more complex mechanism.The intensity of the emission is more affected by Yb^(3+)than Er^(3+),which includes not only the self-quenching of Yb^(3+),but also the dominance in the Yb^(3+)-Er^(3+)cross-relaxation.In this finding may provide new ideas for revealing the reasons for the diminished luminescence of highly doped upconversion nanoparticles and thus for enhancing luminescence.
基金Project supported by the National Natural Science Foundation of China (20071031)
文摘The doping effects of La^3+, Gd^3+ and Lu^3+ on the crystal structure and luminescence properties of (Yo96-x LnxCe0.04)3Al5O12(Ln = Gd, La, Lu) phosphors were studied. The X-ray diffraction patterns presented that with the inerease of the doping concentrations of La^3+ and Gd^3+ ions, the d-value of (Y0.96-xLnxCe0.04)3Al5O12 (Ln = Gd, La) inereased and the larger the doping ion, the stronger the effect would be. The doping amount causing phase transition in (Y0.96-xLnxCe0.04)3Al5O12 decreased with the inerease of the ionic radii of the doping lanthanide ions (La^3+: 0.106 nm, Gd^3+: 0. 094 nm, Lu^3+ : 0.083 nm). The bigger doping ion of Gd^3+ made the emission of (Y0.96-xGdxCe0.04)3Al5O12 move to red spectral region, but the smaller one of Lu^3+ made it blue.
基金supported by the Strategic Priority Research Program of CAS(XDB20000000)the NSFC(Nos.21390392,21473205,and 21731006)+1 种基金Youth Innovation Promotion Association of CASthe Natural Science Foundation of Fujian Province(No.2017J01038)
文摘In this paper,we report for the first time the controlled synthesis of lanthanide ion(Ln3+)-doped tetragonal-phase Na3Zr F7nanocrystals(NCs)via a high-temperature co-precipitation approach.The as-synthesized Na3Zr F7NCs are systematically studied by utilizing the XRD,TEM as well as high-resolution photoluminescence(PL)spectroscopy.The morphology and size for the as-synthesized Na3Zr F7NCs can be finely controlled by changing the experimental parameters such as the amount of precursor,solvent ratio,reaction temperature and time.By utilizing the red-emitting Eu3+ion as an efficient optical/structural probe,the successful hetero-valence doping of Ln3+activators in the lattices of Na3Zr F7NCs is well-established regardless of their different valences and radii between host Zr4+ion and Ln3+dopant.As a result,intense upconversion(UC)luminescence(UCL)ranging from UV to visible and to NIR spectral regions can be readily achieved after the doping of typical UCL couples of Yb3+/Er3+,Yb3+/Tm3+and Yb3+/Ho3+into the lattices of Na3Zr F7NCs when excited by using a 980-nm NIR diode laser.
基金Supported by the National Natural Sciences Foundation of China
文摘The interaction of trivalent lanthanide ions and divalent calcium ions with sph-'ngomyelm bilayer has been studied by FT-Raman spectroscopy.The results showed that the bonding of metal ions to the phosphate group of sphingomyelin bi-iayer,either La3+or Ca2+did not change the conformation of the choline group,that is,O-C-C-N+is still in its gauche conformation.The presence of metal ions changed the states of the interfacial region from liquid-like to amorphous state and even to crystalline.They increased the fluidity of acyl chains of sphingomyelin bilaver and made them packed disorderly.
文摘Five lanthanide porphyrin complexes with 5- (4-nitrophenyl) -10, 15, 20-triphenylporphyrin and acetylacetonate ligands were synthesized and characterized by elemental analysis, IRspectra, Uv-visible spectra, IH NMR. The structures of the complexes were proposed.
基金Project supported by the National Natural Science Foundation of China(51202111)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘In this paper,a series of GdOF-based green phosphors doped with Ho^(3+) and Yb^(3+) ions was prepared by a simple co-precipitation method.The crystal structure s and optical prope rties were investigated in detail.The intensity of the emission of GdOF:Yb^(3+),Ho^(3+) phosphors is enhanced by the effective energy transfer from Yb^(3+) to Ho^(3+),and the optimal luminescence is achieved with the Ho^(3+)doping amount of 0.1 mol%as well as Yb^(3+) doping amount of 5 mol%.Tunable UC emission of samples is achieved by adjusting the doping concentration of Ho^(3+) or Yb^(3+).The purity of the green UC emission is further improved by enhancing the excitation pumping power.In addition,logarithmic functions of green,red and nearinfrared radiation intensities were calculated versus logarithmic function of pump power for further study.A possible UC luminescence mechanism between Yb^(3+) and Ho^(3+) is discussed based on powerdependent UC luminescence spectrum and decay lifetimes.These results suggest that GdOF:Yb^(3+),Ho^(3+)phosphors with bright and high-purity green UC emission have potential applications in the fields of bioimaging,display and illumination.
基金the National Natural Science Foundation of China(No.81971704)the National Key ResearchandDevelopment Program of China(No.2017YFA0205304)the Translational Medicine Research Fund of National Facility for Translational Medicine(Shanghai)(No.TMSK-2021-117)。
文摘Compared with the conventional first near-infrared(NIR-I,700900 nm)window,the short-wave infrared region(SWIR,900—1700nm)possesses the merits of the increasing tissue penetration depths and the suppression of scattering background,leading to great potential for in vivo imaging.Based on the limitations of the common spectral domain,and the superiority of the time-dimension,time-resolved imaging eliminates the auto-fuorescence in the biological tissue,thus supporting higher signal-to-noise ratio and sensitivities.The imaging technique is not affected by the difference in tissue composition or thickness and has the practical value of quan-titative in vivo detection.Almost all the relevant time-resolved imaging was carried out around lanthanide-doped upconversion nanomaterials,owing to the advantages of ultralong luminescence lifetime,excellent photostability,controllable morphology,easy surface modification and various strategies of regulating lifetime.Therefore,this review presents the research progress of SWIR time-resolved imaging technology based on nanomaterials doped with lanthanide ions as luminescence centers in recent years.
基金supported by the National Natural Science Foundation of China(Nos.20574043,20874057)the Key Natural Science Foundation of Shandong Province of China(No.Z2007B02)
文摘A series of c arbosilane dendrimers with acetyl end-group were synthesized. Their structures were characterized by 1H NMR, IR, and MS, respectively. Then dendrimers were coordinated with lanthanide ions (Eu3+ and Tb3+, respectively). The luminescence spectra of the complexes show narrow-width emissions in visible light region. 2009 Sheng Yu Feng. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金supported by the National Natural Science Foundation of China(Nos.12074347,61935009,and 12004346)the Science Foundation for Distinguished Young Scholars of Henan Province(No.212300410019)+1 种基金the Project funded by China Postdoctoral Science Foundation(No.2019M662508)the Young Talent Support Project of Henan Province(No.222300420322).
文摘Luminescent nanothermometry can precisely and remotely measure the internal temperature of objects at nanoscale precision,which,therefore,has been placed at the forefront of scientific attention.In particular,due to the high photochemical stability,low toxicity,rich working mechanisms,and superior thermometric performance,lanthanide-based ratiometric luminesencent thermometers are finding prevalent uses in integrated electronics and optoelectronics,property analysis of in-situ tracking,biomedical diagnosis and therapy,and wearable e-health monitoring.Despite recent progresses,it remains debate in terms of the underlying temperature-sensing mechanisms,the quantitative characterization of performance,and the reliability of temperature readouts.In this review,we show the origin of thermal response luminescence,rationalize the ratiometric scheme or thermometric mechanisms,delve into the problems in the characterization of thermometric performance,discuss the universal rules for the quantitative comparison,and showcase the cutting-edge design and emerging applications of lanthanide-based ratiometric thermometers.Finally,we cast a look at the challenges and emerging opportunities for further advances in this field.