JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2017
·Vol. 100
·期 7
·3061-3069
·
IF 2.841
Shaohua Fan,Shikai Wang,Hongtao Sun,Shiyu Sun,Guojun Gao,Lili Hu
We report efficient dual-mode up-conversion (UC) and down-shifting (DS) emission in a single Yb 3+ /Er 3+ -co-doped β-NaYF 4 microcrystals with controlled morphology and size via a simple Na + ion-exchange modification (IEM) method. IEM well preserves the crystal structure and monodispersed morphology of hydrothermal-synthesized β-NaYF 4 . Meanwhile, IEM gives rise to the significant enhancement of UC emission intensity up to 3800 times and strongly enhanced DS emission intensity of Er 3+ and Yb 3+ by several times in β-NaYF 4 :Yb 3+ ,Er 3+ microcrystals. IEM also strongly prolongs the DS emission lifetimes of Er 3+ and Yb 3+ in visible and near-infrared region. The enhanced UC and DS emission intensities and prolonged lifetimes in β-NaYF 4 :Yb 3+ ,Er 3+ are mainly ascribed to the dispersing of localized Yb 3+ and Er 3+ clusters during IEM.
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高影响因子
Nanoscale
·
2017
·Vol. 9
·期 22
·7666-7673
·
IF 7.367
Xin Su,Xiaoqian Sun,Suli Wu,Shufen Zhang
Photonic crystals (PCs) have long been considered effective for tuning upconversion luminescence due to their photonic band gap (PBG) and the redistribution of density of optical states (DOS). Although the emission intensity can be changed obviously by the PC effect, rarely an obvious lifetime change consistent with theory is observed due to the low refractive index of PS or SiO2 spheres in the commonly used PCs. Herein, CdS/NaYF4:Yb3+,Er3+ composite PCs with a high refractive index contrast are fabricated in one step with upconversion nanoparticles filled inside CdS PCs. When the upconversion emission peak lies at the edge of the PBGs of the composite PCs, a dramatic decrease in lifetime by 28% and 41% is observed for the green and red emissions, respectively. At the same time, obvious emission intensity enhancements are also observed. In contrast, PS PCs with a low refractive index contrast show a slight effect on the lifetime of upconversion luminescence with their emission peak at the edge of the PBGs. Our results agree well with theory and prove that a sufficiently large refractive index contrast is necessary for PCs to dramatically tune the luminescence lifetime and intensity simultaneously.
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PubMed
高影响因子
Journal of Materials Chemistry C
·
2016
·Vol. 4
·期 26
·6327-6335
·
IF 5.066
Weijing Yao,Qingyong Tian,Jun Liu,Zhaohui Wu,Shuyuan Cui,Jin Ding,Zhigao Dai,Wei Wu
Up-conversion materials can be applied in anti-counterfeit fields because of their high concealment and high up-conversion fluorescence efficiency. Herein, different lanthanide ions-doped β-NaYF4 up-conversion micro-particles (UCMPs) with uniform hexagonal morphology were synthesized on a large-scale (more than 0.5 g) via a facile hydrothermal method. It is very interesting to find out the fluorescence intensity and the eventual morphology of the UCMPs were highly dependent on the reaction conditions. Then, the optimal UCMPs with uniform morphology and strong fluorescence intensity were selected as promising candidates for preparing ink. Eventually, we successfully printed designable and multicolor fluorescent patterns on flexible substrates (common paper and polyethylene terephthalate, PET) using the as-prepared β-NaYF4:Yb3+,Tm3+/Er3+/Eu3+ UCMPs inks. Under ambient conditions, the printed patterns on conventional paper are invisible, while such printed patterns on PET are white. However, all the patterns could display blue, yellow-green and green fluorescence patterns under the irradiation of a 980 nm laser when using the β-NaYF4:Yb3+,Tm3+/Er3+/Eu3+ UCMPs inks. We envision that the UCMPs fluorescent inks-based flexible and rapid screen printing patterns have enormous potential for anti-counterfeit and security applications.
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DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Jinfeng Wang,Rui Jiang,Shuo Zhou,Bin Feng,PanPan Mou,Hongze Yang,Yanmei Zhang,Xianbo Zhang,Guosong Chen,Ying Hong
Using nitrilotriacetic acid (NTA) as the capping agent, β -NaYF 4 upconversion microcrystals (UCMCs) were successfully synthesized via a hydrothermal synthesis method. Systematic investigations were conducted to evaluate the influence of NTA/Ln molar ratio, NaF/Ln molar ratio, and pH on the morphology, size, and crystal phase characteristics of the UCMCs. Multiple characterization techniques, such as scanning electron microscope (SEM) and X-ray diffractometer (XRD), were employed to elucidate these effects. The experimental findings reveal that these parameters exert a substantial influence on the morphology and size of the UCMCs, with the crystal phase alterations primarily governed by variations in the NaF/Ln molar ratio. Furthermore, a comprehensive exploration of the growth mechanism of UCMCs was undertaken based on the modulation of reaction time. The emission spectra of the synthesized UCMCs were meticulously investigated, unveiling that microcrystals exhibiting larger size and enhanced crystallinity display more pronounced luminescent properties. Comparative analysis with UCMCs synthesized using ethylenediaminetetraacetic acid (EDTA) and sodium citrate (Na 3 Cit) as capping agents, which are extensively applied in diverse fields, demonstrated the superior luminescence properties of the newly obtained NTA-UCMCs. In addition, NTA-UCMCs were also employed for the fabrication of transparent and flexible fluorescent films. This research thus presents a novel approach for the synthesis of highly luminescent UCMCs, holding promise for various applications in practical contexts.
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高影响因子
Journal of Physical Chemistry C
·
2011
·
IF 4.524
Xiaojiao Kang,Ziyong Cheng,Chunxia Li,Dongmei Yang,Mengmeng Shang,Ping’an Ma,Guogang Li,Nian Liu,Jun Lin
Core–shell structured up-conversion luminescent and mesoporous NaYF4:Yb3+/Er3+@nSiO2@mSiO2 nanospheres were prepared by coating mesoporous SiO2 layers with different thicknesses on NaYF4:Yb3+/Er3+ nanoparticles via a simple two-step sol–gel process. The obtained sample shows a typical mesoporous structure and well-dispersed spherical morphology with a narrow size distribution. The nanospheres exhibit little cytotoxicity (via MTT assay), and ibuprofen (IBU) was used as a model drug to access the release properties of the system in detail. The amount of IBU adsorbed in mesoporous channels increases with the thickness of the ordered mesoporous silica shell coated on the NaYF4:Yb3+/Er3+ nanoparticles. The in vitro release study of IBU reveals a release profile in two steps: an initial diffusion-controlled release, followed by a slower release rate. Furthermore, upon excitation by a 980 nm near-infrared laser, the nanospheres emit green (2H11/2 and 4S3/2 → 4I15/2) and red (4F9/2 → 4I15/2) fluorescence of Er3+ even after the loading of IBU. Interestingly, the emission intensity of Er3+ in the bifunctional (mesoporous and luminescence) drug carrier increases with an increase of the cumulative released amount of the model drug (IBU). Thus, the extent of drug release can be easily identified, tracked, and monitored based on the change of the up-conversion luminescence. These results suggest that the core–shell structured NaYF4:Yb3+/Er3+@nSiO2@mSiO2 nanospheres are a promising material for controlled drug release.
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高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Jiwei Liang,Huiping Gao,Mengji Yi,Wenjia Shi,Yuefeng Liu,Zhenlong Zhang,Yanli Mao
β-NaYF 4 :Yb 3+ , Tm 3+ @ TiO 2 core-shell upconversion nanoparticles (UCNPs) were synthesized and incorporated into the TiO 2 mesoporous layer of perovskite solar cells (PSCs). Changes of the upconversion spectra of the UCNPs suggest the existence of the electron injection from NaYF 4 :Yb 3+ , Tm 3+ to the conduction band (CB) of TiO 2 through the NaYF 4 :Yb 3+ , Tm 3+ /TiO 2 nano-heterojunctions. The core-shell UCNPs that incorporated into the TiO 2 mesoporous layer not only act as the upconversion centers to use the NIR light but also serve as the light scatter centers to enhance the light harvesting. When using mesoporous layer containing the core-shell UCNPs in PSCs, the efficiency of the best devices is 16.27%, which is about 16.38% higher than that of the devices without core-shell UCNPs (13.98%). The significant enhancement in the performance of the PSCs is attributed to light scattering, NIR light upconversion and electron injection from the UCNPs to the CB of TiO 2 .
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高影响因子
JOURNAL OF RARE EARTHS
·
2017
·
IF 2.429
Song LI,Song YE,Xiao CHEN,Tianhua LIU,Zhuang GUO,Deping WANG
Yb 3+ and Er 3+ ions co-doped NaYF 4 nanocrystals were synthesized with different amounts of NaOH via oleic acid (OA)-assisted hydrothermal process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and photoluminescence spectra were used to characterize the products. The result indicated that the introduction of NaOH into the initial reaction solution effectively promoted the cubic (α-) to hexagonal (β-) phase transition of NaYF 4 :Yb 3+ ,Er 3+ nanocrystals, while excessive amount of NaOH favored the formation of α-NaYF 4 :Yb 3+ ,Er 3+ nanocrystals. Besides, with the increase of NaOH amount, the morphologies of β-NaYF 4 :Yb 3+ ,Er 3+ nanocrystals varied from irregular nanobranch to uniform nanorod. Further investigation revealed that the addition of NaOH could facilitate the deprotonation of OA, leading to the formation of oleate (OA − ), and meanwhile increased the concentration of OH − ions, inducing consequently the phase transition and morphology evolution of NaYF 4 :Yb 3+ ,Er 3+ nanocrystals. Moreover, the upconversion luminescence properties of NaYF 4 :Yb 3+ ,Er 3+ nanocrystals were systematically investigated. It was found that the upconversion emissions not only depended on the phase and morphology but also were influenced by the surface groups.
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高影响因子
Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 37
·9770-9777
·
IF 5.256
Shaohua Fan,Guojun Gao,Dmitry Busko,Zhiquan Lin,Shikai Wang,Xue Wang,Shiyu Sun,Andrey Turshatov,Bryce S. Richards,Hongtao Sun,Lili Hu
Monodisperse β-NaYF4:Yb3+,Tm3+ (NYF) hexagonal microplates with efficient near-infrared (NIR)-to-NIR up-conversion (UC) developed via a new ion-exchange modified hydrothermal method are reported. Ion exchange modification (IEM) not only significantly increases the UC intensity by up to 1000 times and prolongs the emission lifetimes of Tm3+ and Yb3+, but also enables the monodisperse morphology and size of hexagonal microplates to be maintained. A high UC quantum efficiency (QE) of 3.1% is obtained for IEM β-NaYF4:20%Yb3+,1%Tm3+ when excited with 980 nm light at a power density of 10 W cm−2. The UC emission properties can be finely tailored by changing the NaF/NYF molar ratio (NYF represents lanthanide doped β-NaYF4) and the doping concentration of Tm3+. The two photon NIR UC emission centered at ∼803 nm (arising from Tm3+: 3H4 → 3H6) dominates the UC emission spectrum and high concentrations of Tm3+ favor NIR UC further. A proof-of-concept optical image of printed patterns is demonstrated to verify their applications in security. These results suggest the promising applications of the newly developed monodisperse β-NaYF4:Yb3+,Tm3+ hexagonal microplates in security, luminescent labels, solid-state lasers, amplifiers, and biomedicine.
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高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 20
·5453-5461
·
IF 5.976
Shaohua Fan,Guojun Gao,Shiyu Sun,Sijun Fan,Hongtao Sun,Lili Hu
Absolute quantum efficiency (QE) of up-conversion (UC) materials is still limited to ∼3%, which strongly limits their applications in many areas. Herein, we report highly efficient UC β-NaYF4:Yb3+,Er3+ micro-cylinders prepared via a newly developed Li+/Na+ ion exchange method (IEM) with absolute QE as high as ∼4.0%. A small amount of Li+ is interstitially incorporated in β-NaYF4:Yb3+,Er3+, which not only maintains well the micro-cylindrical morphology but also enhances the emission intensity by ∼40%, doubles absolute UCQE (∼3.0% under a fixed excitation power density of 15 W cm−2), and prolongs the lifetime. The UC excitation profile is composed of a sharp peak at 976 nm and a weak shoulder at 935 nm. The absolute UCQE of Li+/Na+ IEM β-NaYF4:Yb3+,Er3+ is systemically studied over a wide excitation power density of 0.4–100 W cm−2, and we obtained impressively high UCQE of 4.0% under 60 W cm−2 power density, which is among the highest values in the literature. The application of two green UC emissions of Li+/Na+ IEM β-NaYF4:Yb3+,Er3+ in ratiometric thermometers is successfully demonstrated. The high relative temperature sensitivity (SR) of 1113/T2 and excellent repeatability as indicated by three heating–cooling cycles (293–753 K) suggest their promising application as a temperature sensor.
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高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2016
·
IF 3.42
Huiqiong Yan,Xiuqiong Chen,Jia Shi,Zaifeng Shi,Wei Sun,Qiang Lin,Xianghui Wang,Zihao Dai
The rare earth ion doped upconversion nanoparticles (UCNPs) synthesized by hydrophobic organic ligands possess poor solubility and low fluorescence quantum yield in aqueous media. To conquer this issue, NaYF 4 :Yb 3 + /Tm 3 + UCNPs, synthesized by a hydrothermal method, were coated with F127 and then assembled with chitosan to fabricate the chitosan/NaYF 4 :Yb 3 + /Tm 3 + composite beads (CS/NaYF 4 :Yb 3 + /Tm 3 + CBs) by Pickering emulsion system. The characterization results revealed that the as-synthesized NaYF 4 :Yb 3 + /Tm 3 + UCNPs with an average size of 20 nm exhibited spherical morphology, high crystallinity and characteristic emission upconversion fluorescence with an overall blue color output. The NaYF 4 :Yb 3 + /Tm 3 + UCNPs were successfully conjugated on the surface of chitosan beads by the gelling of emulsion droplets. The resultant CS/NaYF 4 :Yb 3 + /Tm 3 + CBs showed good upconversion luminescent property, drug-loading capacity, release performance and excellent biocompatibility, exhibiting great potentials in targeted drug delivery and tissue engineering with potential tracking capability and lasting release performance.
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DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·
IF 2.7
Yuangong Ma,Wensheng Zhang,Zhifang Wu,Zhishan Liang,Youlin Huang,Qingmei Tan,Tianren Liu,Dongxue Han,Li Niu
In the realm of photocatalysis, effectively utilizing solar energy, especially the near-infrared (NIR) spectrum, presents substantial challenges. To tackle this issue, a novel composite of NaYF4:Yb3+/Er3+@Cu2O@MoS2@Fe3O4 (denoted as NYE@Cu2O@MoS2@Fe3O4) was ingeniously fabricated and assessed for the photodegradation of organic contaminants. By harnessing the distinct properties of upconversion materials, narrow bandgap semiconductors, and magnetic substances, the NYE@Cu2O@MoS2@Fe3O4 catalyst possesses a photodegradation rate of 92% for the rhodamine B dye under NIR light radiation, which is superior to NYE@Cu2O (50%) and NYE@Cu2O@MoS2 (85%). The enhanced performance in the near-infrared photocatalysis of NYE@Cu2O@MoS2@Fe3O4 is mainly attributed to the synergistic effect of various components, which promotes an increase in photo-induced carrier generation and facilitates their efficient transfer and energy utilization under NIR irradiation. This study provides a possible route for the near-infrared photocatalytic degradation of pollutants in areas with limited light or even dark conditions.
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高影响因子
ACS Nano
·
2012
·
IF 11.421
Yunlu Dai,Ping’an Ma,Ziyong Cheng,Xiaojiao Kang,Xiao Zhang,Zhiyao Hou,Chunxia Li,Dongmei Yang,Xuefeng Zhai,Jun Lin
In this study, we report a new controlled release system based on up-conversion luminescent microspheres of NaYF4:Yb3+/Er3+ coated with the smart hydrogel poly[(N-isopropylacrylamide)-co-(methacrylic acid)] (P(NIPAM-co-MAA)) (prepared using 5 mol % of MAA) shell. The hybrid microspheres show bright up-conversion fluorescence under 980 nm laser excitation, and turbidity measurements show that the low critical solution temperature of the polymer shell is thermo- and pH-dependent. We have exploited the hybrid microspheres as carriers for Doxorubicin hydrochloride (DOX) due to its stimuli-responsive property as well as good biocompatibility via MTT assay. It is found that the drug release behavior is pH-triggered thermally sensitive. Changing the pH to mildly acidic condition at physiological temperature deforms the structure of the shell, causing the release of a large number of DOX from the microspheres. The drug-loaded microspheres exhibit an obvious cytotoxic effect on SKOV3 ovarian cancer cells. The endocytosis process of drug-loaded microspheres is observed using confocal laser scanning microscopy and up-conversion luminescence microscopy. Meanwhile, the as-prepared NaYF4:Yb3+/Er3+@SiO2@P(NIPAM-co-MAA) microspheres can be used as a luminescent probe for cell imaging. In addition, the extent of drug release can be monitored by the change of up-conversion emission intensity. These pH-induced thermally controlled drug release systems have potential to be used for in vivo bioimaging and cancer therapy by the pH of the microenvironment changing from 7.4 (normal physiological environment) to acidic microenvironments (such as endosome and lysosome compartments) owing to endocytosis.
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PubMed
高影响因子
危险品化学品经营许可证（带存储）