OPTICAL MATERIALS
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2022
·
IF 3.754
Jingxin Ding,Huazhen Liao,Libin Pang,Deping Wang,Song Ye
Rare earth ions doped core-shell thermometers exhibit improved up-conversion emission behaviors, while the thermal sensitivity is not higher than the corresponding core-only structured luminescent thermometers via the thermal coupled levels based luminescence intensity ratio (LIR) technique. In this work, the core-only β-NaYF 4 : 16Yb 3+ , 4Er 3+ (C–4Er) up-conversion nanoparticles (UCNPs) and the sub 25 nm core-shell β-NaYF 4 : 16Yb 3+ , 4Er 3+ @0.5NaGdF 4 (CS–4Er@0.5Gd) and β-NaYF 4 : 16Yb 3+ , 4Er 3+ @1NaGdF 4 (CS–4Er@1Gd) UCNPs have been successfully synthesized by seed-mediated growth methods for temperature detection. The spectral study indicated that the up-conversion luminescence intensity of CS-4Er@0.5Gd and CS-4Er@1Gd was obviously enhanced compared withC-4Er. Luminescence intensity ratio originated from thermally coupled Stark sublevels (Stark-LIR) of Er 3+ ( 2 H 11/2 (1)(2), 4 S 3/2 (1)(2)(3)) of CS-4Er@0.5Gd and CS-4Er@1Gd has been firstly applied to calculated the relative thermal sensitivity (S R ) of core-shell UCNPs. As a result, S R of CS-4Er@1Gd is the largest among the considered UCNPs, and is increased from 10.95 × 10 −3 /K (LIR) to 17.80 × 10 −3 /K (Stark-LIR), indicating that with Stark-LIR techniques, the nano core-shell sensors behave a larger S R than core-only structured thermometers. This work may lead to an appropriate approach to improve the temperature sensitivity of core-shell thermometers for temperature sensing.
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2013
·Vol. 15
·期 35
·14681-14688
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IF 3.829
Xingyuan Guo,Weiye Song,Changfeng Chen,Weihua Di,Weiping Qin
A novel near-infrared (NIR)-responsive photocatalyst, β-NaYF4:Yb3+,Tm3+@ZnO composites, was prepared by a two-step high temperature thermolysis method. In the NIR-responsive photocatalysis, β-NaYF4:Yb,Tm served as a NIR-to-UV upconverter and provided “UV light” or “necessary energy” to the ZnO catalyst. The energy transfer in the composites and the mixtures of β-NaYF4:Yb,Tm and ZnO was studied by using steady-state and dynamic fluorescence spectroscopy. The NIR photocatalytic activities were investigated by the decomposition of Rhodamine B. It was found that the energy transfer processes dominated the overall photocatalytic activities, and the generation of hydroxyl radicals was the origin of organic pollutant decomposition under NIR irradiation.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2014
·
IF 2.726
Chuanying Wang,Xianhua Cheng
Using a facile hydrothermal method , hexagonal β-NaYF 4 :Yb 3+ 20 mol%, Er 3+ 1 mol% crystals with predictable size and morphology were synthesized and the upconversion (UC) luminescence properties were investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectra were used to characterize the samples. The results indicated that the size and morphology of the crystals can be precisely controlled by tuning the pH values of the initial reaction solution and the molar ratio of NaNO 3 to RE 3+ (RE = Y + Yb + Er), and the mechanism was proposed. The UC luminescence properties of β-NaYF 4 :Yb 3+ /Er 3+ crystals were found to strongly depend on the crystal morphologies and sizes. The peak area ratio of green to red (R/G) increased from 0.29 to 1.03 with pH values increasing from 3 to 10, and increased from 1.03 to 1.26 with the increase of molar ratio of NaNO 3 to RE 3+ from 0 to 90. The emission colors were tuned from pure green to orange yellow. This study provides a facile way to synthesize β-NaYF 4 :Yb 3+ /Er 3+ crystals with predictable morphology and size, and tunable luminescence properties, which can be applicable for other rare earth fluoride compounds.
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高影响因子
Laser & Photonics Reviews
·
2014
·Vol. 8
·期 4
·575-582
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IF 9.313
Wu Suli,Liu Ye,Chang Jie,Ning Yanhui,Zhang Shufen
Upconversion emission intensity and morphology are both important features of NaYF 4 :Yb 3+ , Er 3+ microcrystals. In this paper, myristic acid (MA) is selected as a novel stabilizing ligand to synthesize NaYF 4 :Yb 3+ , Er 3+ through a facile hydrothermal method. Upconversion fluorescence spectra indicate that the emission intensity of product prepared with MA as ligand has increased dramatically compared with the sample prepared using commonly used oleic acid (OA) as ligand. Field emission scanning electron microscopy (FE-SEM) results display that the morphology of NaYF 4 :Yb 3+ , Er 3+ obtained using MA as ligand can be tuned from nanodisk, nanorod to nanotube. Especially, nanotube with clear caves can be prepared directly with proper concentration of base (NaOH). And powder X-ray diffraction (XRD) analysis reveals a relationship between the phase transformation process and the amount of NaOH. With increasing the amount of NaOH, the transition process of cubic phase to hexagonal phase is accelerated. The effect of F − and OH − on the fluorescence properties of NaYF 4 :Yb 3+ , Er 3+ are studied systematically. A gradual increase of the amount of NaF results in a regular increase of the emission intensity. On the contrary, the emission intensity decreases with increasing the amount of NaOH. In addition, reasonable explanations of the influence of F − and OH − on emission intensity are given as well.
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高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Mingye Ding,Zheyan Shen,Yongjun Yuan,Wangfeng Bai,Chunhua Lu,Zhenguo Ji
β-NaYF 4 :Yb 3+ /Er 3+ nanocrystals embedded transparent glass ceramic has been successfully fabricated by direct incorporation of hydrophilic upconversion nanoparticles (UCNPs) into sol-gel silica glass and subsequent heat treatment. The temperature-sensitive upconversion luminescent behaviors of the as-fabricated UCNPs-silica glass ceramic are systemically investigated in order to investigate its potential application as luminescent thermometric medium. Impressively, benefiting from low-phonon-energy environment, highly UC emission for erbium ions in β-NaYF 4 nanophase and high transparency, good chemical/mechanical stability of the oxide glass matrix, the investigated glass ceramic has superiorities of high relative temperature sensitivity (~ 1.16% K −1 ) and excellent thermal stability for accurate temperature sensing. This preliminary study not only provides a reference for fabricating other transparent bulk glass ceramics containing highly luminescent nanomaterials , but also exploits an effective approach for developing high-performance luminescent thermometers.
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高影响因子
MATERIALS RESEARCH BULLETIN
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2018
·
IF 2.873
Zhangxu Chen,Ming-Lai Fu
To extend the activities of TiO 2 to the near infrared (NIR) region and to separate and recycle photocatalysts easily is vital for the high harvest of solar energy for sustainable society. The magnetic NIR activated Fe 3 O 4 @SiO 2 /β-NaYF 4 :Yb 3+ ,Tm 3+ /TiO 2 (FS/UC/T) composites have been synthesized by using the solvothermal method by adding Fe 3 O 4 @SiO 2 and Degussa P25 into the mixed solution of NaOH, ethanol, oleic acid, Re(NO 3 ) 3 and NH 4 F. Moreover, the obtained composites were explored for photocatalytic applications. It was found that FS/UC/T emit UV–vis light under irradiation of 980 nm laser and efficient energy transfer from β-NaYF 4 :Yb 3+ ,Tm 3+ to TiO 2 was verified. The photodegradation experiments for treating methylene blue (MB), rhodamine B (RhB), methyl orange (MO) and colorless phenol were carried out to evaluate the photocatalytic activities of the samples. The photodegradation rates reach 76.62%, 68.48%, 30.05% and 27.16% for MB, RhB, MO and phenol under irradiation of 980 nm laser, respectively, which suggested magnetic FS/UC/T composite is an advanced NIR-driven photocatalyst. Moreover, the magnetic photocatalyst showed easy separation and good stability in the recycled tests. It suggested a promising system to utilize the NIR energy for photocatalysis based on TiO 2 and to utilize the magnetic for separation of photocatalysts, which will contribute to practical environmental remediation in the future.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2018
·
IF 3.779
Ping Xiao,Song Ye,Huazhen Liao,Deping Wang
In this work, the monodisperse spherical pure β-NaYF 4 :Yb 3+ ,Er 3+ core NCs with average size of 7.2 nm were synthesized by using NaOA as sodium source instead of the conventional NaOH, based on which the sub-20 nm β-NaYF 4 :Yb 3+ ,Er 3+ @NaGdF 4 core-shell NCs with magnetic-optical bifunctional properties were successfully obtained with seed-mediated growth method. The magnetization of the core-shell NCs enhanced proportionally with increased shell thickness, and the maximum upconversion intensity was three orders of magnitude increased in the 18.3 nm NaYF 4 : Yb 3+ ,Er 3+ @NaGdF 4 core-shell NCs compare with the corresponding core NCs. Besides, the upconversion mechanism for the core and core-shell NCs were discussed. This work may lead to an ideal platform for the preparation of sub-20 nm spherical NCs with magnetic and optical properties for application in biomedical imaging and drug delivery.
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高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2025
·
IF 2.5
Wang Fangyu,Wen Yijie,Guo Xin,Zhang Xuanhao,Hu Shuai,Yuan Maohui,Han Kai
Upconversion nanomaterials have been extensively applied in many fields owing to their unique optical and electronic properties. In this work, β-NaYF 4 :Yb 3+ /Ho 3+ microcrystals were synthesized by an improved hydrothermal method. The morphology and the composition of the prepared microcrystals were experimentally investigated in detail by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Under the excitation of a 980 nm continuous-wave (CW) laser, the green (541 nm) and red (644 nm) upconversion luminescence (UCL) of Ho 3+ through the energy transfer upconversion processes assisted by the Yb 3+ ions were experimentally studied at the single-particle level. With the gradual increase of excitation intensity in the highly doped Yb 3+ microcrystals, the red UCL was enhanced significantly more than the green UCL and was dominant, resulting in the UCL color finally tuning to pure red. Comparatively, for the lightly doped Yb 3+ microcrystals, the green UCL exhibited a relatively similar increase to the red UCL. The populations of the Yb 3+ and Ho 3+ ions and transitions of the UCL were systematically demonstrated through calculation of the energy levels. Notably, a new UCL at 580 nm was observed, which was ascribed to the transition of 5 F 1 , 5 G 6 → 5 I 7 .
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Chuanying Wang,Xianhua Cheng
β-NaYF 4 :Yb 3+ /Er 3+ microcrystals codoped with Cr 3+ ions were prepared for the first time via a facile hydrothermal method . The influence of doping concentration of Cr 3+ ions on growth and upconversion (UC) luminescence properties of β-NaYF 4 :Yb 3+ /Er 3+ microcrystals were investigated in detail. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra and photoluminescence (PL) spectra were used for characterization. The results demonstrated that the morphology and size of β-NaYF 4 :Yb 3+ /Er 3+ microcrystals were influenced by doping concentration of Cr 3+ ions, the possible mechanism was proposed. The UC intensity of β-NaYF 4 :Yb 3+ /Er 3+ microcrystals was significantly enhanced by doping of Cr 3+ ions. In contrast to β-NaYF 4 :Yb 3+ /Er 3+ microcrystals without doping of Cr 3+ ions, the green and red emission intensities of the microcrystals codoped with 15 mol% Cr 3+ ions were enhanced by 16 and 7 times, respectively. The enhancement of the UC intensities should be ascribed to the distortion of local symmetry around Er 3+ ions, the UC mechanism was discussed. This work will be helpful for improving the UC intensity of other lanthanide-doped UC nano- and micro-crystals.
研究领域:
材料科学
·
无机化学
·
光功能材料
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纳米医学
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生物成像
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分子影像学
·
光学材料
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DOI
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Tingxia Wu,Ying Hong,Lingyu Song,Yongbao Zhu,Jinling Wang,Yuanyuan Zhu,Jing Fang,Guosong Chen
Smuggling has caused serious adverse effects on the global market and national security, among which drug smuggling is increasingly rampant. Thus, the development of high-tech security strategies has become an urgent challenge for customs supervision. Recently, lanthanide ions (Ln 3+ ) doped upconversion nanoparticles (UCNPs) have opened up new ways for security and anti-fake applications due to their unique optical properties under near-infrared excitation. Here, we propose a novel upconversion microcrystal composed of hexagonal phase NaYF 4 :Ln 3+ capped by sodium hexametaphosphate (SHMP), successfully used in customs supervision. The addition of SHMP can not only regulate the morphology of microcrystals, but also significantly improve the luminescence properties of UC. The absolute quantum yield is up to 7% at the low power density of 30 W∙cm −2 , above most currently reported levels. Without adding any organic additives, the precise control of particle phase and morphology (e.g., microrod, hexagonal prism and hollow sphere) would be achieved by adjusting the doping ratio of SHMP/Ln 3+ . As the reaction time extends, the morphology of NaYF 4 :Ln 3+ changes from ellipsoid to microrod, while cubic phase transforms into hexagonal phase. Under the excitation of 980 nm laser, the green upconversion emission of hexagonal NaYF 4 :Ln 3+ microrods is significantly strengthened, which is more powerful than other observed particles with other shapes. This strong upconversion emission that depends on morphology and phase has huge application potential in security anti-counterfeiting and photonic devices .
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高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2020
·
IF 2.726
Hao Tang,Ying Xu,Xianhua Cheng
In this study, Cr 3+ and Mg 2+ co-doped β-NaYF 4 :Yb 3+ /Er 3+ (NYFYE) microcrystals were synthesized for the first time by the facile hydrothermal method . Cr 3+ and Mg 2+ co-doping was confirmed to influence the structure, morphology and UCL property of NYFYE microcrystals. The growth mechanism of NYFYE microcrystals doped with different Cr 3+ and Mg 2+ was discussed in detail. With 16 mol% Cr 3+ and 4 mol% Mg 2+ co-doping into NYFYE, the UC emissions were enhanced to 7 times (green) and 4 times (red) higher than those of the undoped counterpart, and the mechanism was explored by considering the different roles of Cr 3+ and Mg 2+ , the surface quenching and concentration quenching effects. This finding suggests the co-doping of two different impurity ions may be a better approach than corresponding single impurity ion doping for morphology control and UCL intensity enhancement, which is instructive for high performance UC crystals design.
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高影响因子
JOURNAL OF POWER SOURCES
·
2019
·
IF 7.467
Qiyao Guo,Jihuai Wu,Yuqian Yang,Xuping Liu,Jinbiao Jia,Jia Dong,Zhang Lan,Jianming Lin,Miaoliang Huang,Yuelin Wei,Yunfang Huang
The introduction of upconversion materials as spectral converter into photovoltaic devices to harvest and convert near infrared photons to visible photons that can thus be absorbed by perovskite layer is a promising strategy for enhancing the performance of perovskite solar cells . Hence, β-NaYF 4 :Yb 3+ /Er 3+ /Sc 3+ @NaYF 4 rare-earth doped upconversion nanoparticles with core-shell structure are synthesized. The doped rare-earth ions Yb 3+ and Er 3+ convert near infrared light to red and green light, and the Sc 3+ ions enhance the upconversion luminescence efficiency, which broaden the absorption range of solar irradiation and generate extra photocurrent in the solar cells. The surface defects of β-NaYF 4 :Yb 3+ /Er 3+ /Sc 3+ is passivated by the even NaYF 4 shell, which results in the obvious enhancement in upconversion emission intensity. Consequently, the perovskite solar cell based on the rare-earth doped upconversion nanoparticle mesoporous layer achieves a high power conversion efficiency of 20.19%, while the device based on TiO 2 mesoporous layer gets an efficiency of 17.44%.
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高影响因子
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