JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2023
·
IF 4.5
Jiazhuang Chen,Yuke Zhong,Dongdong Wang,Mei Li,Wei Han,Yalan Liu,Weiqun Shi
To further explore the application of the low-temperature molten salt in processing heavy rare earths, the properties of ytterbium in AlCl 3 -NaCl melts have been investigated. In this melt, YbCl 2 powder products are prepared by electrolysis based on the dissolution reaction of Yb metal. The properties of Yb(II) in AlCl 3 -NaCl melts have also been studied in detail. In-situ UV–VIS absorption spectroscopy demonstrates that the coordination of Yb(II) changes in AlCl 3 -NaCl melts with different Lewis acidity, leading to variations in its diffusion ability. In addition, the conversion of Yb(II)/Yb(III) shows typical soluble-soluble reversible electrochemical behavior in strongly acidic AlCl 3 -NaCl. However, the electrochemical behavior of Yb(II) on inert electrodes becomes complicated when the amount of AlCl 3 in AlCl 3 -NaCl melts less than 52 mol%. This change is attributed to the formation of a YbCl 3 passivation film on the inert electrode during the electro-oxidation of Yb(II). Soaking the passivated electrode in the melt can alleviate the passivation. Understanding the electrochemical and spectroscopic properties of ytterbium in AlCl 3 -NaCl melts paves the way for its subsequent applications.
研究领域:
材料科学
·
电化学
·
稀土化学
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DOI
高影响因子
ACS Applied Nano Materials
·
2022
·
IF 6.14
Wubin Lv,Jin Ye,Qiang Wang,Chunsheng Li,Jun Wang,Zhiyong Zhang,Na Niu,Zhiguo Liu,Jiating Xu,Yujie Fu
Rare earth (RE)-based inorganic upconversion nanoparticles (UCNPs) have huge potency for applications varying from bioimaging to theranostics of tumors. For these applications, it is of great importance that UCNPs be expelled innocuously from a living body during a rational period of time after executing their diagnostic and/or therapeutic tasks. Despite great efforts to modulate biodegradability, a reasonable biodegradation rate for currently available UCNPs in weakly alkaline physiochemical buffers has not yet been realized. Herein, to achieve a tunable biodegradation rate for UCNPs, a class of core–shell-structured nanoparticles is invented by heteroepitaxially growing a CaF2:Yb shell with varying Zr4+ doping content on a biodegradable Na3ZrF7:Yb,Er core. The CaF2:Yb,Zr shell can not only enhance the emission intensity but also ensure the overall biodegradation of the nanocrystals. The degradation rate of core–shell UCNPs can be easily modulated by changing the Zr4+ doping content in the shell, and the degradation rate is pH-responsive; thus, tumor acidity-triggered degradation can be realized. When sodium alginate (SA)-modified UCNPs are used for the bioimaging of tumors, the intracellularly degraded metal ions and the released SA molecules can self-assemble through a coordination cross-linking effect, thereby improving the tumor retention of the nanosystems. These discoveries will unequivocally promote the future clinical applications of RE-based UCNPs.
研究领域:
纳米技术
·
生物医学工程
·
材料科学
·
癌症研究
·
光学成像
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产品关联
DOI
高影响因子
Materials Research-Ibero-american Journal of Materials
·
2019
·
IF 1.104
Dan Ho Kim,Tap Tran Duy,Nguyen-Truong Hieu,Ty Nguyen Minh,Zhou Dacheng,Qiu Jianbei
The SiO2-Al2O3-BaF2-TiO2-CaF2 transparent silicate glass-ceramics containing BaF2 nanocrystals were successfully prepared by heat treatment process through conventional melting method. Effects of heat treatment processes and Yb3+ concentration on the downconversion (DC) emission of the co-doped Er3+/Yb3+ transparent silicate glass-ceramics were investigated. With the increase of temperatures and times of heat treatment process, the DC emission intensity of the co-doped Er3+/Yb3+ glass-ceramics was significantly enhanced. At the same time, with the increase of Yb3+ concentration, the value of DC intensity of Er3+/Yb3+ co-doped bands centered at 849, 883 and 1533 nm is maximized when the concentration of Yb3+ reaches 2.5 mol.%. When the concentration exceed 2.5 mol. %, the DC emission intensity of Er3+/Yb3+ co-doped bands centered at 849, 883 and 1533 nm was decreased, owing to the self-quenching effect. It’s interesting that the DC emission intensity of Er3+/Yb3+ co-doped band centered at 978 nm didn’t quench when the Yb3+ concentration exceed 2.5 mol. %. At the same time, the DC mechanism and ET processes between Yb3+ and Er3+ ions were discussed.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zuowei Zhang,Luoning Zhang,Jianjun Xu,Xian He,Baohua Yuan,Chao Chen,Cheng Zou,Qian Wang,Yanzi Gao,Meina Yu,Chuanbao Liu,Huai Yang
Polymer dispersed liquid crystal (PDLC) is a promising candidate for electrically controlled smart window applications because of its energy efficiency, convenience and other advantages. However, its flexibility and heat management capabilities are not effectively evaluated. Herein, a flexible dual-functional intelligent window based on PDLC composite is designed for this purpose, which integrates Ag nanowires as a transparent conductive electrode (TCE) and Tm 3+ /Yb 3+ -Cs x WO 3 (Tm 3+ /Yb 3+ -CWO) as a near-infrared shielding and air purification layer. Specifically, the as-made smart window can control the transmission of both visible and near-infrared light. Furtherly, it also possesses self-cleaning capability. A series of characterization has been carried out. The resistance of the Ag nanowire layer is measured to be 22.47 Ω/sq and the transmittance reaches 78.8 %. Flexibility test shows that when the bending radius is 4 mm, the resistance value of the TCE changes only 6 % after 500 repetitions, indicating good flexibility and stability. The spectrum examination reveals that the near-infrared light shielding efficiency achieves 80 % and the average transmittance of visible light is 76.7 %. The degradation of Rhodamine B (RhB) is used to evaluate the purification performance and result shows that the degradation percentage reaches 70 % in 120 min. Heat-regulation simulation test discloses that the indoor temperature can be decreased by 10 °C. Compared to traditional PDLC windows, the designed flexible window has broader application prospects in areas of architecture, vehicle glass, military stealth materials and so on.
研究领域:
材料科学
·
能源与环境工程
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DOI
高影响因子
ACS Catalysis
·
2026
·Vol. 16
·期 14
·13525-13536
·
IF 13.6
Wang Yue,Zhang Qi,Han Chunqiu,Jia Wenlong,Liu Huai,Zhang Rui,Peng Lincai,Lv Tianping,Ye Liqun,Zhang Junhua
Photocatalytic activation of C–H bonds in biomassderived molecules represents a promising strategy for biomass
upgrading. However, the efficiency of selective C–H bond activation
and oxidation is severely restricted by the sluggish kinetics of photogenerated carriers and the uncontrollable generation of reactive oxygen species. Herein, we delicately dispersed Yb single atoms on
ZnIn2S4 nanosheets that boost the photocatalytic directional activation of C–H in 5-hydroxymethylfurfural (HMF). The optimized
Yb0.8-ZIS achieves a balance between 2,5-diformylfuran selectivity
(99.8%) and production rate (906.6 μmol g–1 h–1
) under ambient
conditions. Mechanistic studies reveal that Yb single atoms not only
effectively modulate the electronic structure of ZnIn2S4 but also
serve as hole extractors, thereby enhancing the separation of photogenerated carriers and the activation of oxygen. Furthermore, the ligand-to-metal charge transfer between Lewis acidic Yb sites and
HMF effectively reduces the electron density of the α-C–H bond, thus accelerating the activation process. This work offers insight
into the rational design of rare-earth single atoms for modulating both charge dynamics and molecular activation in selective C–H
activation and oxidation.
KEYWORDS: Yb single-atom, C–H activation, electronic structure, photocatalytic oxidation, 5-hydroxymethylfurfural
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DOI
高影响因子
JOURNAL OF MODERN OPTICS
·
2024
·
IF 1.2
Hui Ying Zhang,Wan Ying Xie,Peng Zhang,Xiao Hui Li,Zian Cheak Tiu
In this work, NaGdF4: 20%Yb, 2%Er microcrystals with varying contents of Cr3+ doping were obtained by conventional hydrothermal process. The microcrystal phase structure, morphology, upconversion luminescence mechanism, as well as temperature sensing behaviour under different treatment methods were researched. Based on the thermally coupled 2H11/2 and 4S3/2 levels of Er3+ and the dependence of fluorescence intensity ratio (FIR) on temperature, the optical temperature sensing behaviour of micrometer crystals were experimentally demonstrated. The NaGdF4: 20%Yb, 2%Er, 7%Cr microcrystals treated with high-temperature annealing show the best temperature sensing behaviour within the temperature span of 298–498 K. NaGdF4: 20%Yb, 2%Er, 7%Cr microcrystals with high temperature annealing presented the feasibility and promising properties for optical temperature sensing. The endeavour of emerging materials could lay the groundwork for future sustainable photonics engineering industrial growth.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2020
·
IF 2.779
Yuxin Pan,Hui Lin,Jian Liu,Xiaodong Xu,Ruijin Hong,Chunxian Tao,Zhaoxia Han,Dawei Zhang
Yb,Ho:Y 2 O 3 ceramics have been fabricated by Spark Plasma Sintering method (SPS). The microstructure and transmittance of the ceramics sintered from 1623 K to 1673 K were analyzed. The highest in-line transmittance of Yb,Ho:Y 2 O 3 ceramic sintered at 1673 K reached almost 83% at 750 nm with the thickness of 1 mm. The absorption spectra , fluorescence spectra and fluorescence decay curve were recorded at room temperature. The Judd-Ofelt parameters Ω 2 , Ω 4 and Ω 6 were calculated to be 8.33 × 10 −20 cm 2 , 1.81 × 10 −20 cm 2 , and 0.82 × 10 −20 cm 2 , respectively. The intense emission cross section of Yb,Ho:Y 2 O 3 ceramic was 3.43 × 10 −20 cm 2 at 2057 nm with full width at half maximum (FWHM) of 208 nm. The results indicate that Yb,Ho:Y 2 O 3 transparent ceramic can be a promising laser gain medium for laser operation around 2 μm.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2018
·
IF 3.972
Lihua He,Xiao Zou,Xiang He,Fengying Lei,Na Jiang,Qiaoji Zheng,Chenggang Xu,Yongfu Liu,Dunmin Lin
A variety of NaYF4:Yb/Er upconversion materials were successfully synthesized via a facile hydrothermal method by altering the volume ratios (0:1, 1:1, 2:1, 3:1, 4:1, 5:1) of ethanol to water and various alcohols (methanol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, polyethylene glycol, and phemethylol), and the grain size and luminescence of the materials were effectively tailored. The addition of alcohol effectively reduces the grain size of the materials and simultaneously leads to the surprising enhancement of the UC emission. The increase in the volume ratio of EtOH/H2O causes the transformation of the crystal structure of the materials from hexagonal to cubic phase. The particle size of the material with the EtOH/H2O of 2:1 is almost 1000 times smaller than that of the material without EtOH, and the strongest luminescence is observed at the EtOH/H2O of 2:1. The type of alcohol in the solvent exhibits a significant influence on the luminescent properties of the materials. The NaYF4:Yb/Er nanocrystals obtained using different alcohols as solvent possess much a smaller grain size and stronger upconversion luminescence than that using water as solvent, and the NaYF4:Yb/Er materials with n-propyl alcohol exhibit the strongest luminescence intensity. The mechanism of the reduction of grain size and enhancement in the luminescence of the NaYF4:Yb3+, Er3+ upconversion materials has been proposed. This study may suggest a simple method to significantly reduce the grain size and improve the upconversion luminescence properties of NaYF4-based fluorescence material.
研究领域:
材料科学
·
光学
·
纳米技术
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DOI
高影响因子
CRYSTENGCOMM
·
2023
·
IF 3.1
Aihua Zhou,Jiaxin Yang,Yan Li,Chengguo Ming,Yuanxue Cai,Yumiao Pei
Luminescence thermometry has recently been gaining popularity in science and technology fields. However, most reported works have used the fluorescence intensity ratio (FIR) to obtain the temperature based on thermally coupled energy levels (TCLs), which have hindered the sensitivity of the technique and limited its applications. Here, NaYF4:Yb/Tm@NaYF4:Yb/Ho microcrystals were prepared using a hydrothermal method. Based on the non-thermally coupled energy levels (NTCLs) of the double luminescent ionic centers Tm3+ and Ho3+, the materials exhibited temperature-dependent luminescence in the range of 304 K to 574 K. The maximum sensitivities were found to be Sa = 0.135 K−1 at 574 K and Sr = 1.101% K−1 at 484 K based on red (Tm3+) and green (Ho3+) emission bands. This study has provided a promising new strategy to break the TCL restriction and has shown the material to have potential applications in luminescence thermometry.
研究领域:
材料科学
·
光学
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产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2017
·
IF 2.238
Weiwei Li,Haijun Huang,Bingchu Mei,Jinghong Song
In this paper, ytterbium doped strontium fluoride (Yb: SrF 2 ) nanoparticles were synthesized by direct precipitation method. High-speed centrifugation was used to separate high sintering activity of nanopowders from powders with hard aggregated and large size. Using powders at different parts of the centrifugal tube as starting powders, Yb: SrF 2 transparent ceramics was fabricated by hot pressed (HP) method for the first time. Effects of morphology and particle size on the sinterability of Yb: SrF 2 nanopowders were investigated. The transmittance reached 77% at the wavelength of 1200 nm and pores stilled remained in the ceramics. The spectroscopic and thermal properties of Yb: SrF 2 transparent ceramics were also investigated. This paper provides an effective way to obtain well dispersed and high sinterability nanoparticles for SrF 2 ceramics sintering.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2021
·Vol. 101
·期 1
·215-226
·
IF 2.326
Li Ping,Zhao Liuyong,Wang Song,Zhang Xiaohui,Jiang Huaiyuan,Liu Ruizhen,Zhao Nengchuang,Cheng Jian,Xu Caili,Zhao He,Lyu Renliang
Known as one efficient upconversion luminescent material, Rare-earth ions doped natrium yttrium fluoride NaYF 4 :Yb/Re has broad application prospects. However, due to the limitation of the existing preparation methods, it is difficult to realize industrial production. In this paper, the upconversion luminescence microparticles, rare earth ions doped Natrium Yttrium Fluoride NaYF 4 :Yb/Er, were synthesized productively by impinging stream method. Synthesis conditions were optimized as EDTA: Ln to 0.5 and NaF: Ln to 6 (Ln represents the sum of moles of Y, Yb, and Er), reacting temperature and time to 50 °C and 3 h to obtain a high yield of 99.92% and particle with good monodispersity. To get strong upconversion luminescence, the effect of the calcination temperature and the amount of EDTA were investigated. The bright upconversion emissions by excited with laser radiation at 975 nm were found at 510–690 nm. The higher the calcination temperature, the stronger the luminescence and the strongest luminescence occurs when calcined at 600 °C. And the adding of EDTA will decrease the luminescence intensity. However, the sintering of particles at high temperatures and aggregation of particles without EDTA are unfavorable for the application of the products. Based on the above considerations, the optimal calcination temperature was determined at 450 °C, and the ratio of EDTA: Ln is preferred at 0.5. The impinging stream method to prepare upconversion material has the advantages of being simple in the process and equipment, high in output, low in investment, and convenient to be applied and popularized.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
Nanomaterials
·
2018
·Vol. 8
·期 12
·1023
·
IF 3.504
Dandan Ju,Feng Song,Adnan Khan,Feifei Song,Aihua Zhou,Xiaoli Gao,Huimin Hu,Xu Sang,Victor Zadkov
The dual-mode emission and multicolor outputs in the time domain from core-shell microcrystals are presented. The core-shell microcrystals, with NaYF4:Yb/Er as the core and NaYF4:Ce/Tb/Eu as the shell, were successfully fabricated by employing the hydrothermal method, which confines the activator ions into a separate region and minimizes the effect of surface quenching. The material is capable of both upconversion and downshifting emission, and their multicolor outputs in response to 980 nm near-infrared (NIR) excitation laser and 252 nm, and 395 nm ultraviolet (UV) excitation light have been investigated. Furthermore, the tunable color emissions by controlling the Tb3+-Eu3+ratio in shells and the energy transfer of Ce3+→Tb3+→Eu3+were discussed in details. In addition, color tuning of core-shell-structured microrods from green to red region in the time domain could be obtained by setting suitable delay time. Due to downshifting multicolor outputs (time-resolved and pump-wavelength-induced downshifting) coupled with the upconversion mode, the core-shell microrods can be potentially applied to displays and high-level security.Keywords:NaYF4:Yb/Er@NaYF4:Ce/Tb/Eu microrods;dual-mode emission;time-resolved emission spectra;multicolor emission
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）