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Isostructural series of [{Al(H2O)6}{Ln(pda)3}].10H2O: Synthesis, Structure and Photoluminescence
摘要： A new series of six isostructural molecular solids of the composition [{Al(H2O)6}{Ln(pda)3}].10H2O where Ln = Sm, Eu, Gd, Tb, Dy and Yb have been synthesized and structurally characterised. All the solids are built of three major building blocks: the lanthanide dipicolinate anion, {Ln(pda)3}3-, the counter cation, {Al(H2O)6}3+ and a hexameric water cluster in chair form. The cations and the anions supramolecularly aggregate forming a 2D H-bonded sheet; the sheets are further stabilised through hexameric water clusters in chair form and water molecules. The crystals containing Sm, Eu, Tb and Dy showed characteristic emission of lanthanide ions.
关键词： 2,Lanthanide,6-dipicolinic acid,Photoluminescence.
更新于2025-09-23 15:21:21
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Novel lanthanidomesogens based on poly(ethylene glycol) cholesterol ether: Liquid crystal phase behavior and luminescence properties
摘要： Biocompatible systems with luminescent properties attract significant interest as they are broadly used in bioanalysis and medical diagnostics. This paper describes new lanthanide liquid crystals based on an oxyethylated amphiphile with a cholesterol fragment (CholEO10). The complex of physicochemical methods (polarizing optical microscopy (POM), X-ray powder diffraction, FTIR-spectroscopy and luminescent analysis) was used to study liquid crystalline, structural and optical properties of these new biomesogens. Their phase behavior was compared with the behavior a lanthanum-containing analogue without a cholesterol fragment in its structure. A rigid hydrophobic fragment was found to exert a strong influence on lyotropic mesomorphism in aqueous media. The phase transition from a lamellar mesophase to a hexagonal one was observed with decrease of the CholEO10/La3+ complex concentration and addition of water. The study of luminescent properties of CholEO10/Ln3+ complexes, where Ln3+ is Dy3+, Tb3+, or Eu3+, revealed that their characteristic emission occurs in the yellow, green and red spectral ranges. Optical characteristics of new mesogens were estimated. Mesogenic CholEO10/Tb3+ and CholEO10/Eu3+ complexes demonstrate longer lifetime of their excited state as compared with the C12EO10/Ln3+/H2O complex.
关键词： Cholesterol derivatives,Liquid crystals,Luminescence,Poly(ethylene glycol),Lanthanide
更新于2025-09-23 15:21:21
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Design of lanthanide-based metal-organic frameworks with enhanced near-infrared emission
摘要： A strategy based on the use of ligand steric hindrance and metal doping is reported for the design and synthesis of near-infrared (NIR) emitting lanthanide-based metal–organic frameworks (MOFs). The lanthanide ions are free of coordinated solvents, and the resulting NIR-MOFs are highly emissive and exhibit long luminescence lifetimes.
关键词： metal doping,ligand steric hindrance,lanthanide-based metal–organic frameworks,luminescence,near-infrared emission
更新于2025-09-23 15:21:01
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Quantum Dot-Based Sensitization System for Boosted Photon Absorption and Enhanced Second Near-Infrared Luminescence of Lanthanide-Doped Nanoparticle
摘要： Efficient energy transfer is a promising strategy in overcoming the inherent limits of narrow band and weak absorption of lanthanide ions due to the nature of 4f-4f transitions. Herein, we introduce a nanoparticle-sensitized nanoparticle system where a near-infrared-emitting quantum dot (QD) is used as a sensitizer with broadband photon absorption for lanthanide-doped nanoparticle (LNP) to generate second near-infrared (NIR-II) emission. The NIR-II luminescence of Er3+-doped LNP by Ag2S QD sensitization displays an enhancement of ~17-fold in intensity and ~10-fold in brightness over bare LNP because of increased absorptivity and overall broadening of the absorption spectrum of LNP. Furthermore, QD-sensitized LNP system exhibits excellent photostability, and is able to improve the signal to noise ratio of tumor NIR-II imaging via in situ crosslinking of QD and LNP. The QD-sensitized LNP system for luminescence enhancement opens a potential avenue for efficient energy transfer in complex nanoparticle-nanoparticle systems.
关键词： Lanthanide-Doped Nanoparticle,Photon Absorption,Second Near-Infrared Luminescence,Quantum Dot,Sensitization System
更新于2025-09-23 15:21:01
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Dual-mode light-emitting lanthanide metal-organic frameworks with high water and thermal stability and its application in white LEDs
摘要： It is well known that the up-conversion luminescence from lanthanide metal-organic frameworks (Ln-MOFs) is difficult to achieve, and thus, there are few reports on dual luminescence-based MOFs. Here, dual-mode light-emitting Ln-MOFs are synthesized using a low-cost hydrothermal method. Our results show that the obtained Ln-MOFs not only have high thermal stability (up to 420 degrees) but also are stable in deionized water. The dual-mode up and down-conversion luminescence is simultaneously observed from Er-Eu-MOFs. The temperature-dependent fluorescence decay time is calculated to be ranged from 0.46 ms to 0.36 ms for temperatures from100 K to 300 K. We suggested that this phenomenon was because the number of phonons participating in the MOF matrix increases with temperature during the luminescence process, and the phonons interact with the electrons in the material. The values of the J-O parameters calculated from the emission spectra indicated that the symmetry around Eu3+ ions in Eu-MOF is the highest, which was also higher than that of Er-Eu-MOF. To explore the potential applications of Eu-MOFs in white light-emitting diodes (LEDs), red emission from Eu-MOFs was combined with blue, green, and yellow emissions from metal halide perovskites to achieve white light emission. The white light with excellent color quality and vision performance was obtained. These findings demonstrate that the Ln-MOFs are potentially successful materials for the applications in white LEDs.
关键词： high thermal stability,Dual-mode luminescence,LEDs,MOFs,lanthanide
更新于2025-09-23 15:21:01
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Synthesis of eight isostructural 2D lanthanide coordination polymers assembled by rigid furan-2,5-dicarboxylic acid and flexible adipic acid as linkers and exploration of luminescent Eu/Tb polymers as efficient and sensitive sensors for nitroaromatic compounds
摘要： Detection of hazardous chemicals is crucial for a healthy and safe environment as well as for the well-being of humans. A confluence of chemistry and engineering continues to improve the sensitivity and selectivity for several classes of harmful chemicals with the promise of cheap and portable sensing. Herein, following the function-oriented research strategy, eight novel lanthanide coordination polymers (Ln-CPs) have been successfully assembled with the framework composition [Ln(2,5-FDC)0.5(Adip)(H2O)2] (Ln = Nd (1), Sm (2), Eu (3), Gd (4), Tb (5), Dy (6), Ho (7), Er (8), 2,5-FDC2? = furan-2,5-dicarboxylate, Adip2? = Adipate) under solvothermal synthesis conditions. The structural analysis indicates that all the eight CPs have the same structural features. All compounds crystallize in the orthorhombic crystal system (space group Pnma) with point symbol {33·44·53} and consist of 2D cem topological type. The linkers 2,5-FDC2? and Adip2? exhibit μ2-κ4,Z1:Z1:Z1:Z1 and μ3-κ5,Z2:Z1:Z1:Z1 coordination modes respectively. The as-synthesized polymers were characterized by powder X-ray crystallography, infrared spectroscopy, thermogravimetric analysis, and photoluminescence studies. CP-3 and CP-5 are promising luminescent lanthanide coordination polymers (Ln-CPs) and function as efficient sensors for the detection of nitroaromatic compounds at the ppm level in mix N,N′-dimethyl formamide-aqueous medium via the luminescence quenching mechanism.
关键词： furan-2,5-dicarboxylic acid,lanthanide coordination polymers,adipic acid,luminescent sensors,nitroaromatic compounds
更新于2025-09-23 15:21:01
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Urchin-like TiO2 structures decorated with lanthanide-doped Bi2S3 quantum dots to boost hydrogen photogeneration performance
摘要： The formation of heterojunctions between wide- and narrow-bandgap photocatalysts is commonly employed to boost the efficiency of photocatalytic hydrogen generation. Herein, the photoactivity of urchin-like rutile particles is increased by decorating with pristine as well as Er- or Yb-doped Bi2S3 quantum dots (QDs) at varied QD loadings (1–20 wt%) and doping degrees (1–15 mol%), and the best hydrogen evolution performance is achieved at Er and Yb contents of 10 mol%. Specifically, a hydrogen productivity of 1576.7 μmol?gcat?1 is achieved after 20-h irradiation for TiO2 decorated by 10 mol% Yb-doped Bi2S3 QDs. Theoretical calculations show that the introduction of defects into the Bi2S3 lattice through Er/Yb doping promotes the creation of the levels and facilitates transport of photogenerated charges during the photocatalytic process.
关键词： quantum dots,photocatalysis,TiO2,lanthanide doping,Bi2S3,hydrogen generation
更新于2025-09-23 15:21:01
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Self-Assembly of Europium-Containing Polyoxometalates/Tetra- <i>n</i> -alkyl Ammonium with Enhanced Emission for Cu <sup>2+</sup> Detection
摘要： Lanthanide-containing polyoxometalates (POMs) can be used to detect various materials, but their luminescence in water has suffered enormous limitations due to the strong fluorescence quenching. Herein, to resolve this problem, three-dimensional nanoparticles built by mixed Weakley-type europium-containing POMs (Na9[EuW10O36]·32H2O, abbreviated to EuW10) and tetra-n-alkyl ammonium (TA) with enhanced fluorescent properties have been designed in aqueous solution using an ionic self-assembly (ISA) technique, which is mainly driven by the electrostatic interaction between EuW10 and TA. The morphology and fluorescent properties of the system as well as some influencing factors (alkyl chain length, amino group, and inorganic salt concentration) were systematically investigated. The results indicated that the fluorescent intensity of EuW10/tetramethylammonium bromide (TMAB) composite increased about 14 times, whereas the extent of increase of fluorescence for EuW10/tetraethylammonium bromide (TEAB) and EuW10/tetrabutylammonium bromide (TMAB) composites gradually decrease due to the bulkier steric hindrance of the longer alkyl chain. Besides, the luminescence of EuW10/TMAB nanoparticles is pH responsive, and the reversibility of their structures and luminescence can be realized upon the addition of NaOH/HCl. Moreover, the EuW10/TMAB system also shows great fluorescence-sensing behavior, which could detect Cu2+ with a detection limit of 0.15 μM. Our work provides a facile construction strategy for a functional fluorescent complex via POMs-based supramolecular self-assembly in aqueous solution, which will be further used in biomarkers and sensors.
关键词： Cu2+ detection,fluorescence enhancement,ionic self-assembly,lanthanide-containing polyoxometalates,pH-responsive
更新于2025-09-23 15:21:01
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Europium and terbium lanthanide ions co-doping in TiO2 photoanode to synchronously improve light-harvesting and open-circuit voltage for high-efficiency dye-sensitized solar cells
摘要： In this study, we explore the effects on the incorporation of europium (Eu3+) and terbium (Tb3+) rare-earth ions into titanium dioxide (TiO2) photoanodes in dye-sensitized solar cells (DSSCs). X-ray photoelectron spectroscopy (XPS) studies affirm that the Eu3+ ions are arranged at the cationic locales of Ti4+ in the matrix whereas the site inhabitance was remunerated by Tb3+ ions, supporting that the anatase phase stays unaltered without generating any new deformities. Additionally, the Eu3+ ions decidedly changed the conduction band minimum of TiO2, actually, Tb3+ ions contrarily conversion because of various vacant trap states in the band gap. Besides, the photoinduced electron transfer estimations show an efficient interfacial charge transfer for co-doped TiO2 (kET = 3.1 ns) contrasted with the bare TiO2 (2.6 ns). DSSCs based on Eu3+/Tb3+ co-doped TiO2 display higher efficiency (9.11%) than those for the bare TiO2 (7.20%) and the exclusively Eu3+ (8.01%) or Tb3+ (7.10%) doped samples, which is ascribed to the joined impact of a faster electron transportation and longer electron lifetime in the co-doped TiO2 film. This work may open another approach to further improve the performance of DSSCs by Eu3+/Tb3+ co-doping technique, advancing the development of DSSCs toward commercial applications.
关键词： Co-doping process,Europium (Eu3+)/terbium (Tb3+) lanthanide ions,Stability,Photoanodes,DSSCs,Titanium dioxide (TiO2) nanopowders
更新于2025-09-23 15:21:01
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Up-Conversion Luminescence Properties of Lanthanide-Gold Hybrid Nanoparticles as Analyzed with Discrete Dipole Approximation
摘要： Up-conversion nanoparticles (UCNP) under near-infrared (NIR) light irradiation have been well investigated in the field of bio-imaging. However, the low up-conversion luminescence (UCL) intensity limits applications. Plasmonic modulation has been proposed as an effective tool to adjust the luminescence intensity and lifetime. In this study discrete dipole approximation (DDA) was explored concerning guiding the design of UCNP@mSiO2-Au structures with enhanced UCL intensity. The extinction effects of gold shells could be changed by adjusting the distance between the UCNPs and the Au NPs by synthesized tunable mesoporous silica (mSiO2) spacers. Enhanced UCL was obtained under 808 nm irradiation. The original theoretical predictions could not be demonstrated to full extend by experimental data, indicating that better models for simulation need to take into account in homogeneities in particle morphologies. Yet, one very certain conclusion resulting from the DDA calculations and experiments is that the absorbance can blue-shift with more Au NPs added and the absorbance can-red shift for samples with enhanced silica sizes in the UCNP@mSiO2-Au structures. Furthermore, when the DDA model is more consistent with the practical structure (dispersed Au NPs instead of Au shell), the theoretical absorbance occurs almost the same as the practical absorbance. All in all, the DDA could fit the extinction effect of Au perfectly and be suitable for guiding how to design the UCNP and Au.
关键词： lanthanide-based composites,surface plasmon resonance,up conversion nanoparticles,discrete dipole approximation
更新于2025-09-23 15:21:01