DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 31
·10838-10844
·
IF 4.39
Xia Xu,Meirong Fu,Penghui Li,Min Yang
While photothermal therapy is widely applied in phototherapy, there are still challenges in developing new generation phototherapy materials with precise diagnostic functions. Here we report the construction of a pH responsive upconversion fluorescence imaging precisely guided photothermal therapy system, namely NaYF4:Yb3+/Er3+@NaYF4@MnO2@Au nanocomposites, which can effectively avoid light damage to non-target tissues. Owing to the fluorescence resonance energy transfer between the upconversion nanocrystal donor and MnO2 and Au acceptor, the upconversion fluorescence is completely quenched. However, in pH 5.3 PBS buffer, MnO2 is gradually broken down, and the upconversion fluorescence is partially recovered, which could be used for upconversion fluorescence imaging to precisely guide photothermal therapy under 980 nm excitation. Simultaneously, due to the absorption of 980 nm excitation light and the emission bands of Er3+ (2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transition), temperature increment of core@shell@MnO2@Au could reach 35.5 °C under 980 nm excitation at 0.8 W cm−2. The core@shell@MnO2@Au nanocomposites are supposed to contribute significantly in the biological applications of photoluminescence imaging and photothermal therapy.
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JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Weichang Li,Qiang He,Jixi Xu,Chongyun Shao,Shiyu Sun,Shaohua Fan,Lili Hu
The efficient NIR-to-NIR upconverter of LiYF 4 :Yb 3+ ,Tm 3+ (simplified as LYF:Yb,Tm) was synthesized by a modified hydrothermal method in this work. The synthesized LYF:Yb,Tm has well controlled morphology of monodisperse micrometer sized octahedrons. XRD pattern confirms its pure tetragonal LiYF 4 structure. The LYF:Yb,Tm exhibits a dominating NIR UC emission at ~793 nm along with relative weak blue and red UC emissions under 976 nm LD excitation. The optimal concentrations of Yb 3+ and Tm 3+ ions for NIR up-conversion (UC) emission are 20 mol% and 0.6 mol%, respectively. The internal UC quantum yield (IUCQY) of this LYF:Yb,Tm in NIR band is tested to be 5.1% at 959 nm LD excitation power density (PD) of 120 W/cm 2 . The UC emission mechanism is discussed based on UC fluorescent behaviors of Yb 3+ and Tm 3+ . The results of fluorescent labeling indicate its potential applications in fluorescent markers, solar cells and 3D flat panel displays .
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DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 43
·15231-15237
·
IF 4.174
Guodong Zhang,Yi Wei,Peipei Dang,Hui Xiao,Dongjie Liu,Xinke Li,Ziyong Cheng,Jun Lin
Double perovskites have attracted wide attention due to their low toxicity and good thermal stability. Doping with active elements is a promising method to endow perovskites with excellent optical, electrical or magnetic properties. Herein, a facile aqueous solution method is developed to synthesize Bi3+–Yb3+ co-doped Cs2Na0.6Ag0.4InCl6 double perovskite. Besides the intrinsic warm white self-trapped exciton (STE) emission that originated from the Cs2Na0.6Ag0.4InCl6 host, the samples also exhibit a strong near-infrared emission assigned to the 2F5/2 → 2F7/2 transition of octahedral coordinated Yb3+ ions upon excitation with ultraviolet light. The optimized sample shows a markedly high photoluminescence quantum yield of 84.7%. The photophysical studies such as photoluminescence (PL) and photoluminescence excitation spectra, temperature-dependent PL spectra, and PL decay curves reveal that the strong Yb3+ emission is attributed to the energy transfer from STEs to the Yb3+ ions. Finally, the lead-free double perovskite phosphor-converted LED containing visible and NIR regions was fabricated, with 8.92 mW output power at 100 mA drive current. The results show the great potential of the as-prepared crystals in optoelectronics applications.
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高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 40
·14030-14045
·
IF 4.174
Kailian Zhang,Jie Guan,Ping Mu,Kai Yang,Yu Xie,Xiaoxiao Li,Laixi Zou,Weiya Huang,Changlin Yu,Wenxin Dai
To effectively enhance the utilization of clean sunlight energy, harvesting a large percentage of near infrared (NIR) light is significant. One of the commonly used effective methods for modifying semiconductors is by co-doping upconversion materials on semiconductors to heighten the photocatalytic efficiency. In this work, Yb3+/Tm3+ co-doped InVO4 nanosheets were synthesized by a facile hydrothermal path, and the crystal phases, morphologies, surface chemical compositions, as well as optical properties were characterized. Yb3+/Tm3+ co-doped InVO4 revealed significantly enhanced photoactivity towards chromium(VI) reduction and methyl orange oxidation under visible or NIR light irradiation. Furthermore, 5YT-IV presented the highest electrocatalytic performance and photocatalytic production of H2O2 under visible light irradiation, requiring low overpotential and low Tafel slope (390 mV dec−1) for hydrogen evolution reaction than that of the bare InVO4 (731 mV dec−1), and as well improved the yield of photocatalytic H2O2 production by about 3.5 times. This was primarily ascribed to intensive light absorption resulting from the benign upconversion energy transfer of Yb3+/Tm3+ and the boosted charge separation caused by the intermediate energy states. Moreover, the presence of h+ and ˙O2− as the main oxidative species played a significant role during the photocatalytic oxidation process of methyl orange and electrons played a decisive role in Cr(VI) reduction. This study provides a promising platform for efficiently utilizing the visible-NIR energy of sunlight in the field of photocatalytic H2O2 production and for alleviating environmental pollution in future.
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ACS Applied Nano Materials
·
2020
·
IF 0
Junshan Hu,Ruonan Wang,Rangrang Fan,Fengyi Wang,Huiyu Xiong,Zhenghu Huang,Lixin Liu,Hao Fu
Here, we report a nanocomposite with excellent photothermal performance promising for photothermal treatment. This nanocomposite is prepared by linking Au nanorods (NRs) to NaGdF4:18% Yb3+, 2%Er3+@NaYF4 core–shell upconversion nanoparticles (UCNPs) with bridging of polyethylene glycol molecules. Solutions with the composite nanoparticles can be heated by the irradiation of a near-infrared 980 nm laser, and the photothermal effect in terms of temperature rise can reach 21.3 °C with excitation power density as low as 0.090 W/cm2. This highly effective photothermal performance is attributed to coincidence of the emission band of the UCNPs and the absorption band of the Au NRs, which facilitates the light-to-heat conversion. The structure of the composite and the concentration of the Au NRs in the solution are also optimized through the emission intensity, green-to-red intensity ratio, and the photothermal effect in this work. Compared with previous research studies, the strength in the lower irradiation power density makes the nanocomposite promising for further photothermal treatment and temperature sensing.
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OPTICAL AND QUANTUM ELECTRONICS
·
2020
·Vol. 52
·期 6
·1-8
·
IF 1.842
Wang Weirong,Tuo Tianye,Jiang Chun
A facile pathway for solid-state material luminescence enhancement is proposed here by coating graphene on the surface of luminescent material. Ln 3+ (Yb 3+ /Er 3+ )-doped germanium tellurite glasses are prepared by conventional melting and quenching method. With the excitation of 980 nm laser diode, the photo-luminescence intensities of the graphene-coated and uncoated glass samples are measured with different incidence angle of excitation light. When the incidence angle is less than 15°, luminescence enhancement can be observed in the coated samples compared with uncoated one. The insight for the enhancement is also discussed.
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JOURNAL OF RARE EARTHS
·
2019
·
IF 2.846
Zaifa Pan,Yingting Wen,Tao Wang,Kai Wang,Yuanjie Teng,Kang Shao
Novel PEI-modified NaBiF 4 :Yb 3+ /Er 3+ upconversion nanoparticles (UCNPs) with hollow structure were prepared by a surface modification free one-step solvothermal method and applied as a luminescent probe to determinate water content in organic solvents . XRD , SEM and HRTEM results demonstrate that the obtained PEI-NaBiF 4 :Yb 3+ /Er 3+ UCNPs are pure hexagonal phase with uniform size. The successful modification of PEI on the UCNPs surface was evidenced by ζ-potential test, XPS and TG analysis . These synthesized UCNPs are disintegrated into smaller nanoparticles in the presence of water and thus result in a surface quenching effect, which show the features of 0–100% wide range water response in various organic solvents. The sensing performance towards real samples was validated by the water content determination in beer, rum and white spirit. Furthermore, the luminescence intensity variation of the PEI-modified NaBiF 4 :Yb 3+ /Er 3+ enable the test visualization and ease of portability.
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Results in Physics
·
2019
·
IF 3.042
Biao Zheng,Cheng Zhang,Chunlei Huang,Jinquan Hong,Yuliang Li,Jun Wang,Lin Lin,Zhiqiang Zheng
Multifunctional NiO@Gd 2 O 3 :Er 3+ ,Yb 3+ hollow nanocomposites (NCs) with mesoporous, upconversion (UC) luminescent and magnetic properties are synthesized by a facile hydrothermal process. Transmission electron microscope (TEM) and scanning electron microscope (SEM) images reveal that the samples have hollow structures with double shells of UC layer and magnetic layer. N 2 adsorption/desorption isotherm analysis shows the samples have large surface area of 29.052 m 2 /g and typical mesoporous structure. Multicolored UC luminescence at 521 nm, 541 nm and 654 nm are obtained under 980 nm laser excitation. In addition, the measured magnetic hysteresis loops indicate the samples exhibit high superparamagnetic behavior (15.8 emu/g). These multifunctional NCs have potential applications in the field of fluorescence probe, targeted therapy, magnetic separation, etc.
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高影响因子
PHYSICA B-CONDENSED MATTER
·
2018
·
IF 1.453
Wenbo Peng,Tao Pang
In this paper, Y 2 Mo 4 O 15 :Yb 3+ /Er 3+ upconversion phosphors are prepared by a co-precipitation method. In the case of 20% Yb 3+ doping, the intense green upconversion luminescence is obtained, which can be attributed to the energy transfer from Yb 3+ -MoO 4 2- dimer to Er 3+ that suppresses the multi-phonon relaxation of 4 I 11/2 to 4 I 13/2 . Similar the Yb 3+ sensitization, the dimer sensitization is also dependent on the Yb 3+ concentration. When the Yb 3+ concentration exceeds 20%, the luminescence is quenched by the cross relaxation and energy migration between dimers. A method for evaluating the reliability of temperature measurement standards is reported. Moreover, in term of the reliable temperature scale, the maximum absolute sensitivity of sample doped with 20% Yb 3+ is determined to be 0.0117 K -1 . Favorable sensing ability and strong upconversion luminescence indicate that the optimum sample is potentially applicable as the optical thermometric materials.
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Nanoscale
·
2018
·Vol. 10
·期 40
·19031-19038
·
IF 7.233
Qiuhong Min,Lei Zhao,Yushuang Qi,Jing Lei,Wenbo Chen,Xuhui Xu,Dacheng Zhou,Jianbei Qiu,Xue Yu
An amorphous layer acting as a quenching center at the surface of oleic acid-capped NaGdF4:Yb3+/Tm3+ nanoparticles is observed directly, which can be reconstructed via a novel post-chemical annealing process. The amorphous phase of the surface layer of NaGdF4:Yb3+/Tm3+ nanoparticles gradually crystallizes as the post-chemical annealing temperature increases; meanwhile, the good dispersibility of the as-obtained nanoparticles is maintained. The reduction of surface defects and higher local symmetry of the crystal field environment around the doped rare-earth ions contribute to drastically increased up-conversion (UC) emission intensity of the NaGdF4:Yb3+/Tm3+ nanoparticles. In particular, the blue emission of Tm3+ at 450 nm enhances 10-fold after the post-chemical annealing process at 250 °C compared with the counterpart without further surface-state treatments. The color gamut of well-crystallized NaGdF4:Yb3+/Tm3+ with a modified surface covers the blue to yellow region in CIE chromaticity coordinates via a non-steady-state UC process. The results indicate that the surface states of these UC nanoparticles can be feasibly improved via the post-chemical annealing process without encouraging agglomeration, which further optimizes their UC properties for practical applications.
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JOURNAL OF NANOPARTICLE RESEARCH
·
2018
·Vol. 20
·期 6
·1-13
·
IF 2.127
Cheng Yuan,Sun Kangning
YVO 4 :Yb 3+ ,Er 3+ ; YVO 4 :Yb 3+ ,Tm 3+ ; and YVO 4 :Yb 3+ ,Er 3+ ,Tm 3+ were all synthesized via sol-gel method with a subsequent thermal treatment. Specifically, YVO 4 :Yb 3+ ,Er 3+ ,Tm 3+ phosphors were prepared with different annealing temperatures to study the influence of temperature. The transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffractometer (XRD), and photoluminescent (PL) spectrofluorometer were used to investigate the morphology, crystal structure, and up-conversion luminescent properties of all samples. In summary, all samples were granular-like nanoparticles and well crystallized with the same tetragonal phase as YVO 4 . Under the irradiation at 980 nm, YVO 4 :Yb 3+ ,Er 3+ phosphors can generate green emission at 525 and 553 nm and red emission at 657 nm, while YVO 4 :Yb 3+ ,Tm 3+ phosphors can generate blue emission at 476 nm, red emission at 648 nm, and near-infrared emission at 800 nm. Notably, YVO 4 :Yb 3+ ,Er 3+ ,Tm 3+ samples can exhibit green emission, blue emission, red emission, and near-infrared emission at the same time, which might endow the as-prepared samples with potential applications in many fields, such as luminous paint, infrared detection, and biological label.
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Nanoscale
·
2012
·Vol. 5
·期 3
·1047-1053
·
IF 5.914
Fuyao Liu,Qi Zhao,Hongpeng You,Zhenxin Wang
Here, a two-step method has been developed for synthesizing carboxy-terminated NaYF4: Yb3+, Er3+@SiO2 core@shell nanoparticles (UCNP@SiO2) with ultrathin shell (1.5 nm). First, the NaYF4: Yb3+, Er3+ upconverting nanoparticles (UCNPs) were prepared using solvothermal technology; then, silica shells (SiO2) were deposited on the nanocrystals to form core–shell structures by the hydrolysis of tetraethylorthosilicate (TEOS). The ultrathin SiO2 shell was obtained by increasing surfactant amount and decreasing TEOS amount in the reaction mixture. Carboxyethylsilanetriol (CTES) was used to generate the carboxy group on the particle surface. The carboxy-terminated UCNP@SiO2 are ideally suited for biolabeling and bioimaging applications because the as-prepared nanoparticles have extreme colloidal and optical stabilities, and the carboxy groups on the particle surface easily react with amino residues of biomolecules. As an example, we reported on the interactions of Ricinus Communis Agglutinin (RCA 120) conjugated UCNP@SiO2 with HeLa cells. The excellent performance of the RCA 120 conjugated UCNP@SiO2 in cellular fluorescence imaging was demonstrated.
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