JOURNAL OF MOLECULAR STRUCTURE
·
2020
·
IF 2.463
Xingbang Dong,Huanjun Zhang,Yang Yang,Shiquan Feng,Zheng Wang,Chaosheng Yuan,Kun Yang,Xuerui Cheng
InNbO 4 and InNbO 4 :Eu 3+ phosphors were synthesized by solid-state reaction method. The structural stability and crystal field under high pressure are investigated up to 34.5 GPa using in-situ Raman and luminescence spectra . The evolution of Raman and luminescence spectra with pressure of InNbO 4 revealed one reversible phase transition at around 12 GPa. A progressive red shift and luminescence quenching were observed for InNbO 4 :Eu 3+ phosphors during compression. The pressure-induced variation of local environment and crystal field around Eu 3+ ions was analyzed using Judd–Ofelt (J-O) intensity parameter Ω 2. Both the parameter Ω 2 and luminescence property were indicative of a pressure-induced lower asymmetry around Eu 3+ sites in InNbO 4 . These results suggest that the pressure has a great influence on fluorescence intensity and energy levels of Eu 3+ ions.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2018
·
IF 4.155
Li Yinong,Tian Chen,Liu Weizhen,Xu Si,Xu Yunyun,Cui Rongxin,Lin Zhang
Nano-Mg(OH)2 is attracting great attention as adsorbent for pre-concentration and recovery of rare earth elements (REEs) from low-concentration solution, due to its superior removal efficiency for REEs and environmental friendliness. However, the nanoparticles also cause some severe problems during application, including aggregation, blockage in fixed-bed column, as well as the difficulties in separation and reuse. Herein, in order to avoid the mentioned problems, a carbon cloth (CC) supported nano-Mg(OH)2 (nano-Mg(OH)2@CC) was synthesized by electrodeposition. The X-ray diffraction and scanning electron microscopy analysis demonstrated that the interlaced nano-sheet of Mg(OH)2 grew firmly and uniformly on the surface of carbon cloth fibers. Batch adsorption experiments of Eu(III) indicated that the nano-Mg(OH)2@CC composite maintained the excellent adsorption performance of nano-Mg(OH)2 toward Eu(III). After adsorption, the Eu containing composite was calcined under nitrogen atmosphere. The content of Eu2O3 in the calcined material was as high as 99.66%. Fixed-bed column experiments indicated that no blockage for Mg(OH)2@CC composite was observed during the treatment, while the complete blockage of occurred to nano-Mg(OH)2 at an effluent volume of 240 mL. Moreover, the removal efficiency of Mg(OH)2@CC was still higher than 90% until 4,200 mL of effluent volume. This work provides a promising method for feasible application of nanoadsorbents in fixed-bed process to recycle low-concentration REEs from wastewater.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Yuan Wang,Zhikai Liang,Kezhou Jiang,Yifang Lin,Daomiao He,Jinhui Liu,Weixian Wang,Jingfei Wang,Bin Deng,Dan Zhang,Ruijin Yu
A novel single-phase trivalent europium activated red-emitting SrLaNaTeO 6 phosphor was first synthesized in a process of traditional high-temperature solid-state. The phase purity, morphology, and spectroscopy of the prepared phosphor were analyzed. Under 395 nm excitation, the photoluminescence (PL) spectra of the SrLaNaTeO 6 :Eu 3+ products mainly contained five dominant sharp peaks. The intense red emission peak at 615 nm was the typical 5 D 0 → 7 F 2 electric dipole transition of Eu 3+ . The optimum product of high quenching concentration was the SrLaNaTeO 6 :0.90Eu 3+ , which reached a high internal quantum efficiency (IQE) of 90.6%. The SrLaNaTeO 6 :0.90Eu 3+ was estimated to have R c of 6.57 Å and possessed high color purity of 100.0%. The phosphors exhibited excellent thermal stability and high activation energy ( E a = 0.29 eV). The prepared white light-emitting diode (WLED) had a high color rendering index (CRI) R a of 92 and a low correlated color temperature (CCT) of 5008 K. In conclusion, the phosphors have potential as red components for WLEDs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2023
·
IF 5.2
Xiayu Liang,Qingle Zeng
Based on the Hard-Soft-Acid-Base theory, we developed and synthesized a unique crystalline adsorbent called MIL-101(Cr)-SMA-ED-PMG (SMA: styrene maleic anhydride; ED: ethylenediamine; PMG: N,N -di(phosphonomethyl)glycine). This adsorbent consists of polymer chains that are abundant in carboxyl and phosphate Lewis hard base groups. This was performed to enhance the efficient recuperation of electrophilic Lewis hard acid rare earth elements . The Neodymium(III) (Nd 3+ ) and Europium(III) (Eu 3+) ions reached adsorption equilibrium in the MIL-101(Cr)-SMA-ED-PMG material after 6 h at pH 5. The adsorption of Nd 3+ and Eu 3+ follows the pseudo-second-order kinetic and Langmuir models. The maximum adsorption capabilities were 102.7 mg/g for Nd 3+ and 110.4 mg/g for Eu 3+ . In addition, when applying a concentration of 0.3 mol/L of HNO 3 or HCl, the adsorbent was nearly completely desorbed, and it remained stable for five cycles. The order of adsorption for the different REE ions was as follows: Eu 3+ > Nd 3+ > Ce 3+ > La 3+ . The MIL-101(Cr)-SMA-ED-PMG compound demonstrated a remarkable 84 % selectivity in adsorbing Eu 3+ compared to the other metal ions in the mixture (Na + , Mg 2+ , Co 2+ , Ni 2+ , and Zn 2+ ). Furthermore, the adsorption of Eu 3+ was not significantly influenced by changes in the aqueous conditions. The experiment conducted on a zinc ore simulated leachate exhibited the material remarkable capacity for Eu 3+ separation and enrichment. MIL-101(Cr)-SMA-ED-PMG exhibits strong adsorption properties, exceptional selectivity, effective desorption, and significant potential for the recovery of rare earth elements (REEs).
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 20
·1-15
·
IF 2.8
Xie Zhuojia,Jiang Xinyu,Zhang Weijian,Zou Zhengguang
With the development of the current times, the demand for refrigeration is in every aspect. Nevertheless, the necessity for new refrigeration materials is immediate because of the greenhouse effect and the destruction of the atmosphere. Therefore, perovskite materials have been investigated. La 0.8− x Eu x Ca 0.1 Sr 0.1 MnO 3 (LECSMO) ( x = 0.05, 0.10, 0.15) powder samples were prepared using the sol–gel method (S–G). The structure, magnetocaloric effect, and magnetic of LECSMO have been explored. X-ray diffraction (XRD) indicates that all samples belong to the rhombohedral perovskite structure of the Pbnm space group. The magnetic research of LECSMO revealed that the samples doped with Eu 3+ exhibited a ferromagnetic (FM) to paramagnetic (PM) transition around the Curie temperature (Tc). As the amount of Eu 3+ doping is added, Tc decreased from 264 to 194 K. Normalization and Banerjee’s criterion confirmed the second-order phase transition of the LECSMO near Tc. The maximum magnetic entropy change ( \(-\varDelta {S}_{M}^{max}\) ) for LECSMO ( x = 0.05, 0.10, 0.15) is 5.39, 4.52, and 4.35 J/(kg·K) when the applied magnetic field (H) = 5 T, respectively. Further, the relative cooling power (RCP) of LECSMO is 282.20 J·kg − 1 , 305.20 J·kg − 1 , and 323.15 J·kg − 1 , respectively.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2019
·
IF 4.309
Xiaolei Lu,Shuxian Wang,Shuxin Liu,Peng Du,Zhengmao Ye,Xuefei Geng,Xin Cheng
Ca2SiO4 is a phase-change material, and γ- and β-Ca2SiO4 usually coexist in the sintered product. The overlap of the diffraction data between the two polymorphs makes the relevant phase identification difficult. In this work, the Eu3+ rear-earth fluorescence probe is introduced in the preparation of Ca2SiO4, and the obtained result indicates that the introduction of Eu3+ ions facilitates the increase in the content of β-Ca2SiO4 in the final product. In addition, the differences of the local coordination environments between the two Ca2SiO4 phases obviously influence the crystal-field splittings of Eu3+ ions, especially in the 5D0 → 7F0 nondegenerate and 5D0 → 7F1 magnetic dipole transition regions. On the basis of the excitation from the Eu3+–O2– charge-transfer band, the low-temperature spectral changes are systematically discussed. The transition area ratios of 5D0 → 7F0/5D0 → 7F2 and 5D0 → 7F1/5D0 → 7F2 present a positive and negative correlation with the increase of the excitation wavelength, respectively. The four nonequivalent 5D0 → 7F0 emission peaks with low to high wavelengths are identified as Eu3+ ion-occupied Ca(β-2) (571.8 nm), Ca(β-1) (573.8 nm), Ca(γ-2) (577.6 nm), and Ca(γ-1) (578.9 nm) sites. Besides, the relationship between the phase content of γ-Ca2SiO4 and the spectral change for the 5D0 → 7F0 emissions of the Eu3+ ions is also built. It is fitted by an exponential correlation function and is quite suitable for the prediction of the phase content of γ-Ca2SiO4 based on the measured spectra. The findings in this study manifest the promising application of the Eu3+ fluorescent probe in phase identification and enrich the analysis method in inorganic phase-change materials.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 14
·2398
·
IF 5.719
Chunhui Song,Qifa Song,Ziyou Ding,Yingchao Han
In this study, we synthesized polyacrylic acid (PAA)-Ca (Eu) nanoclusters as a luminescence sensor of phosphate ion by a complex method, and we aimed to achieve the quantitative detection of PO43−based on the sensitivity of the charge transfer band of Eu3+to anionic ligand. The resulting PAA-Ca(Eu) nanoclusters showed a well-dispersed and a dot-like morphology, with an ultra-small diameter (the average size of 2.17 nm) under high resolution transmission electron microscopy(HRTEM) observation. A dynamic light scattering particle size analyzer (DLS) showed a hydrodynamic size of 2.39 nm. The (PAA)-Ca (Eu) nanoclusters as a luminescence sensor showed a significantly higher sensitivity for PO43−than other anions (CO32−, SiO32−, SO42−, SO32−, Br−, Cl−, F−). The luminescence intensity displayed a linear increase (y = 19.32x + 74.75, R2> 0.999) in a PO43concentration range (0–10 mM) with the concentration of PO43−increase, and the limit of detection was 0.023 mM. The results showed good recovery rates and low relative standard deviations. These (PAA)-Ca (Eu) nanoclusters are hopeful to become a luminescence sensor for quantitatively detecting PO43−.
研究领域:
材料科学
·
分析化学
✓ 已验证
DOI
高影响因子
Chemosensors
·
2022
·Vol. 10
·期 12
·527
·
IF 4.229
Anheng Gu,Guo-Hui Pan,Huajun Wu,Liangliang Zhang,Ligong Zhang,Hao Wu,Jiahua Zhang
Orthorhombic ZrTiO4is an attractive dielectric material; its optical properties are, however, less known. In this paper, we reported on the microstructure and luminescence studies of pristine ZrTiO4and Eu3+-doped ZrTiO4phosphors. The results indicated that two types of TiO6octahedra, the isolated/ localized and coupled/delocalized, coexisted in host matrix. Eu3+doping could induce oxygen vacancy defect states located below the bottom of the conduction band. Pristine ZrTiO4showed bright yellow luminescence via STEs recombination at defects sites at low temperatures, but significant thermal quenching occurred due to STEs migration to quenching centers at elevated temperatures. Effective host sensitized energy transfer to Eu3+was observed in ZrTiO4:Eu3+phosphors and yielded the red characteristic emissions of Eu3+. Anomalous STEs luminescence enhancement and spectral blue-shift in the excitation spectra with higher Eu3 +concentration appeared and were explained by considering three factors: competitive absorption between electron transitions from the top of the valence band to the defect states and host conduction band, Eu3+doping driving the production of more isolated TiO6octahedra, and energy back-transfer from Eu3+activators to other titanate groups. On the basis of the dual-emitting combination strategy involving host STEs and Eu3+luminescence, ZrTiO4:Eu3+phosphors were demonstrated to be ratiometric self-referencing optical thermometric materials, with a working range of 153–313 K and a maxima of relative sensitivity to ~1.1% K−1at 243 K.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 43
·15312-15321
·
IF 6.4
Rui Rui Yang,Fangrui Cheng,Bang Lan
Trivalent rare earth Eu3+-doped luminescent materials have been used successfully for illumination and displays due to their narrow emission lines and extreme stability. Extending the excitation band to the UV, near UV and blue region via doping lanthanide ions as a sensitizer is highly desired for white LED application. However, the complex redox reaction and forward/backward energy-transfer pathway between the sensitizer ion and Eu3+ ion in the same lattice of the phosphor host limits the potential of this strategy. Herein, we present the luminescence properties of hierarchical porous composite materials with the formula Tb(C12H8N2)2(NO3)3@Ca0.9Eu0.1MoO4 and report how interfacial energy-transfer enhanced the absorption range of the Eu3+-doped material in the UV region. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images illustrated that the obtained Ca0.9Eu0.1MoO4 had a hierarchical porous structure, and the Tb(C12H8N2)2(NO3)3 was evenly filled inside the holes or the surface. The photoluminescence and decay data indicated the existence of interfacial forward energy transfer from Tb3+ → Eu3+. Furthermore, the thermal stability of the composited Tb(C12H8N2)2(NO3)3 was improved, indicating the potential of the composite materials for application in UV light-emitting diodes.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 8
·期 3
·1143-1150
·
IF 6.641
Zhizhen Wang,Zhen Song,Lixin Ning,Quanlin Liu
Warm-color persistent luminescent materials are strongly desired for signage markings and medical imaging in comparison with green or blue counterparts. Herein we report a novel yellow long-persistent phosphor, Nb-doped Sr3SiO5:Eu2+, with a peak wavelength of ∼580 nm and persistence time of more than 14 hours at the 0.32 mcd m−2 threshold value after UV radiation. A combination of thermoluminescence (TL), thermoluminescence excitation (TLE), electron paramagnetic resonance (EPR) measurements and density functional theory (DFT) calculations reveals that the persistent luminescence enhancement is attributed to a significant Nb-induced increase of oxygen vacancies that act as electron trapping centers with appropriate trap depths. Groups of time-dependent color-change images are realized with this material, which has potential applications as anti-counterfeit and indicator marks. This investigation also expands the application of transition metal (TM) ions to the field of persistent luminescence and would motivate further exploration of TM substitutions to design and improve silicate or aluminosilicate persistent phosphors with superior performance.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
ELECTROANALYSIS
·
2014
·Vol. 26
·期 12
·2710-2715
·
IF 2.502
Qi-Le Li,Ning Bao,Shou-Nian Ding
Phosphate anions are determined based on the electrochemiluminescence (ECL) of CdSe quantum dots (CdSe QDs) capped with 3-mercaptopropionic acid. The ECL gets quenched with the introduction of Eu 3+ ions, but it is restored on the further addition of phosphate anions. The sensing mechanism might be due to the strong and specific interaction between phosphate anions and the Eu 3+ ions, leading to the releasing of CdSe QDs from aggregates. On the basis of the quenching/recovery ECL behaviors, the ECL sensor offer acceptable sensitivity, high selectivity, and a linear response from 0.1 to 120 µM with a detection limit of 0.03 µM (3δ) for phosphate anions.
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
OPTIK
·
2020
·
IF 2.187
Mingjing Bian,Hongyan Zhang,Jun Zhang,Zhijun Li
The influence of post-annealing on optical properties of Eu-doped ZnO (ZnO:Eu 3+ ) microsphere synthesized by hydrothermal method has been studied. The intrinsic deep defect emission of ZnO and the transition emission of both 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 related to Eu 3+ have been observed under excitation at 325 nm. The photoluminescence (PL) spectra reveal that ZnO annealed in N 2 is more favorable for Eu 3+ being doped into ZnO, which is helpful to greatly enhance the red light emission of ZnO:Eu 3+ . Alkaline conditions are more conducive to the formation of intrinsic deep defects in ZnO lattice, but they are not so conducive to the doping of Eu 3+ ions into ZnO lattice. From Gaussian deconvolution analysis of PL spectrum for ZnO:Eu 3+ , it can be seen that intrinsic defects of ZnO in N 2 atmosphere may efficiently assist energy transfer from ZnO host to Eu 3+ ions to enhance Eu 3+ intrinsic red light emission. There are blue light (446 nm), green light (525 nm) and stronger red light (618 nm) which are simultaneously obtained. This work could pave a way for high performance of white light emission application.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）