CRYSTENGCOMM
·
2022
·Vol. 24
·期 34
·6001-6008
·
IF 3.756
Heyan Wu,Yunhao Liang,Yue Ma,Jun Yang,Shanshan Hu
This work begins with a study of the synthesis of multi-color luminescence phosphors, which is followed by a discussion of the temperature sensitivity of AgBi(MoO4)2:Yb3+/Er3+. Uniform and approximately spherical particles of AgBi(MoO4)2-based phosphors were prepared by a simple one-step hydrothermal method without adding any surfactant. We obtained a series of rich green, yellow, blue, and white luminescence phosphors by doping Ln3+ (Ln3+ = Yb3+, Er3+, Ho3+, Tm3+) into the AgBi(MoO4)2 matrix, and an analysis of various correlative factors was made, especially for the amounts of doping ions. Furthermore, the investigation of the temperature sensitivity of AgBi(MoO4)2:Yb3+/Er3+ revealed that the fluorescence intensity becomes lower with increasing temperature from 323 to 573 K. The fluorescence intensity ratio (FIR) of the two thermal coupling energy levels (2H11/2, 4S3/2) of Er3+ was calculated, and the absolute sensitivity of the obtained phosphor reached a maximum value of 1.32% K−1 at 463 K, as obtained by fitting the FIR as a function of temperature, which is a relatively high level compared with other related materials. This material is expected to be used as a highly sensitive FIR thermometer.
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高影响因子
MATERIALS RESEARCH BULLETIN
·
2022
·
IF 5.6
Mei-Hong Liu,Teng-Teng Li,De-Long Zhang
Micron-sized GdNbO 4 :Er 3+ /Yb 3+ phosphors were prepared by employing a high-temperature solid-state reaction. The crystalline phase, morphology, composition, spectroscopic properties, and impact of rare-earth ion concentration, temperature and high salinity environment were systematically characterized. The extracted results show that phosphor is dominated by the existence of the GdNbO 4 crystalline phase. Their morphology and agglomeration phenomenon are strongly dependent on the rare-earth concentration. The phosphor exhibits also excellent up-conversion luminescence (UCL) properties under 980 nm excitation, while a two-photon process accounts for UCL. The following optimal concentrations were selected for enhanced UCL intensity: 10 mol% for Yb 3+ and 3 mol% for Er 3+ . The phosphor shows excellent thermometric performances including strong UCL, good thermal stability, appropriate sensitivity and a wide sensitivity response range. To evaluate the accuracy of the present optical thermometer, the temperature of a heated bench has been comparatively measured by using the proposed optical thermometer and a commercial thermocouple with an accuracy of 1 K. By comparing the temperature values measured by the two methods, it can be concluded that the present optical thermometer has an accuracy better than 1.6 K. In addition, the phosphor exhibits good chemical stability in high salinity environment. Interestingly, its crystalline phase, structure, and UCL spectral structure, intensity and color are all preserved after one-month immersion into a high salinity solution.
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高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2022
·Vol. 37
·期 3
·393-398
·
IF 1.271
Hou Huayu,Gan Lin,Wang Youfa,Wang Wei
Nd 3+ -doped NaGdF 4 : Yb, Tm nanocrystals were synthesized by an improved high-temperature thermal decomposition method, and the effects of doping concentrations on the crystal structure, phase composition, and upconverted fluorescence intensity were also investigated. The results reveal that the introduction of Nd 3+ ions does not cause the transformation of the crystal phase, but induce the change of the unit cell parameters. Meanwhile, the fluorescence intensity of the synthesized nanocrystals when co-doped with 3 mol% Nd 3+ is the strongest under the excitation of 980 nm laser, which is 3.9 times that of the Nd 3+ -free doped nanoparticles, and the average size is 62.9 nm. And it is located in the blue area of the CIE coordinate diagram, and the corresponding color purity is 91.81% under the same experimental conditions. The resulting nanocrystals show the potential as excellent fluorescence labeling and in vivo imaging probes.
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高影响因子
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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PubMed
高影响因子
OPTICAL MATERIALS
·
2021
·
IF 3.08
Yue Li,Linna Guo,Tiesheng Li,Bowen Yang
The ultra-small Lu6O5F8: 1%Er3+/10%Yb3+ up-conversion nanoparticles (UCNPs) were prepared via a co-precipitation method and used for detection of metal ions . Compared with other metal ions (Na+, Mg2+, Al3+, Fe2+, Co2+, Cd2+, etc), the up-conversion luminescence (UCL) intensity was reduced by 90% in the presence of Cu2+. Moreover, Strong quenching (65%) of the emission was observed upon the addition of Cu2+ in the concentration range of 0–10 μM. Meanwhile, the Cu2+ luminescence quenching mechanism was studied in detail. Under the 980 nm (1550 nm) excitation, the red UCL intensity of (Lu0.79Y0.1)6O5F8: 1%Er3+/10%Yb3+ and (Lu0.85Gd0.04)6O5F8: 1%Er3+/10%Yb3+ UCNPs enhanced about 4.67 (19.3) times and 3.95 (8.89) times than that of Y3+, Gd3+-absent samples, respectively. The temperature-sensing effect of Lu6O5F8: 1%Er3+/10%Yb3+ was also studied in detail, including not only this thermally coupled level (Er3+ 2H11/2, 4S3/2), but also the non-thermally coupled levels (Er3+ 2H11/2, 4F7/2). The absolute (S a ) and relative sensitivity (S r ) of Lu6O5F8: 1%Er3+/10%Yb3+ based on non-thermally coupled levels is much higher than that based on thermally coupled levels in the 293–473 K range. The maximum S a and S r is 0.087 and 0.0185 K −1 at 293 K. These meaningful results indicate that Lu6O5F8: 1%Er3+/10%Yb3+ materials have broad prospects in UCL multifunctional applications.
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高影响因子
MATERIALS RESEARCH BULLETIN
·
2021
·
IF 4.641
Mei-Hong Liu,De-Long Zhang
Er 3+ /Yb 3+ -codoped NaLa(WO 4 ) 2 phosphor samples with different Er 3+ and Yb 3+ doping levels were synthesized by solid-state chemical reaction for optical thermometry and fully characterized. The results show that each phosphor sample mainly consists of NaLa(WO 4 ) 2 crystalline phase and has a nominally stoichiometric chemical composition. The phosphor grains have massive polyhedron morphology, good size homogeneity with a mean value of ∼5 μm and a cutoff phonon energy of 927 cm −1 . The 530 and 550 nm upconversion fluorescence of Er 3+ in the phosphor samples and their temperature characteristics were investigated under 980 nm excitation. The results show that the phosphor exhibits strong upconversion fluorescence and the maximum fluorescence intensity is observed at the optimal Er 3+ and Yb 3+ doping levels of 5 and 20 mol%, respectively. The two-photon process is responsible for the upconversion fluorescence. The spectral structure of either 530 or 550 nm fluorescence band is thermally stable. The peak absolute thermal sensitivity is observed at ∼490 K and has a peak value of ∼9 × 10 -3 K -1 . As expected, Er 3+ or Yb 3+ doping level has little effect on the thermal sensitivity. The phosphor displays a wide dynamical response range of thermal sensitivity from 293 to 800 K, where the sensitivity varies within (6.5–9.0) × 10 -3 K -1 . A comparison study shows that the temperature characteristics obtained from the cooling procedure are almost the same as those obtained from the heating procedure. Besides, the effects of Er 3+ /Yb 3+ doping level and heating/cooling on fluorescence color chromaticity were also studied. Based on the results, the Er 3+ /Yb 3+ -codoped NaLa(WO 4 ) 2 phosphor shows strong fluorescence, good thermal stability, high thermal sensitivity and broad response range of thermal sensitivity. Thus, it is a promising material for thermal detection over a wide temperature range of 293−800 K.
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高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Chunyan Zhang,Zhendong Fu,Feng Hong,Jingzhi Dou,Tengri Dong,Yunxiao Zhang,Dan Li,Guixia Liu,Xiangting Dong,Jinxian Wang
NIR light accounts for 50% of total solar energy, but only a small amount of the energy is applied to photocatalytic reactions. The incorporation of upconversion nanoparticles with semiconductor materials is an effective tactics to exploit NIR-driven photocatalyst . In this work, we report a composite material that can convert NIR light into UV–Vis photons. The light conversion material is composed of NaBiF 4 : Yb 3+ , Tm 3+ up-conversion nanocrystals . The petal-like Bi 2 WO 6 is used as a semiconductor photocatalyst to directly degrade model pollutants, such as RhB. By controlling the morphology of Bi 2 WO 6 , the contact area between the semiconductor photocatalyst and the pollutant molecules is increased. The preparation of “double bismuth” composite material NaBiF 4 :Yb 3+ , Tm 3+ /Bi 2 WO 6 provides the possibility to make full use of sunlight. Under the excitation of simulated sunlight, the photocatalyst of NaBiF 4 :Yb 3+ , Tm 3+ /Bi 2 WO 6 reaches the highest degradation efficiency of 98% in 27 min. Compared with Bi 2 WO 6 , the prepared composite photocatalyst shows better photocatalytic performance, which is attributed to the effective energy transfer between NaBiF 4 :Yb 3+ ,Tm 3+ and Bi 2 WO 6 . The capture tests were used to detect active species used in the degradation process. After four continuous photocatalytic cycles, about 95% of RhB solution is degraded. Under the simulated solar light illumination, the photocatalytic mechanism of the composite photocatalyst is discussed. The results propose a promising system to improve the photocatalytic activity through the efficient use of sunlight.
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高影响因子
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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PubMed
高影响因子
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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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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高影响因子
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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高影响因子
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