RSC Advances
·
2021
·Vol. 11
·期 34
·20746-20751
·
IF 3.361
Raheel Ahmed Janjua,Obaid Iqbal,Muhammad Aqeel Ahmed,Abdullah A. Al-Kahtani,Sara Saeed,Muhammad Imran,Abdul Ghafar Wattoo
A comprehensive strategy has been developed to construct nano-sized homogeneous and heterogeneous core/shell structures of NaYF4 host. Synthesis conditions of cubic phase/α-NaYF4 and hexagonal phase/β-NaYF4 are discussed. Pure cubic NaYF4:Yb,Er nanocrystals were synthesized with different average sizes extending from 7 nm to 15 nm by varying the reaction time. Temperature and time thresholds of hexagonal nucleation were determined and utilized for controlled core/shell structures of different phases. α-NaYF4:Yb,Er@α-NaYF4, α-NaYF4:Yb,Er@β-NaYF4, β-NaYF4:Yb,Er@α-NaYF4, and β-NaYF4:Yb,Er@β-NaYF4 core/shell structures were prepared by adopting the required conditions to achieve the desired phase. Excess sodium was used to grow hexagonal shell over metastable cubic core under controlled conditions of reaction time and temperature to prevent the structural transition of the core. Upconversion emission spectra have also been obtained. UCL integrated intensities demonstrated about 5-fold enhancement for α-shell over α-core as compared to the core alone and 22-fold enhancement with β-shell. On the other hand, α-shell over β-core exhibited 5-fold enhancement and β-shell over β-core exhibited 6-fold enhancement.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2020
·
IF 4.189
Yue Hu,Yanmin Yang,Xuefeng Zhang,Xin Wang,Xiaoxiao Li,Yunqian Li,Tianyi Li,Hongwu Zhang
Here, an X-ray-excited super-long afterglow phosphor β-NaYF4:Tb3+ has been discovered for the first time. After X-ray irradiation, the green emission can persist for more than 240 h. After 120 h, the power density of afterglow reached 3.76 × 10–6 W·m–2, which can be clearly observed by the naked eye under dark vision. Also, combined with the results of thermoluminescence and photoluminescence, the super-long afterglow emission of β-NaYF4:Tb3+ can be ascribed to the tunneling model associated with F centers. More importantly, the super-long green afterglow emission of β-NaYF4:Tb3+ has been successfully used as an in vivo light source to activate g-C3N4 for photodynamic therapy and bacteria destruction. Furthermore, super-long persistent luminescence of β-NaYF4:Tb3+ could be repeatedly charged by X-rays for many cycles, which indicates that the phosphors have high photostability under repeated cycles of alternating X-ray irradiation.
研究领域:
材料科学
·
医学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
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.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2013
·Vol. 15
·期 19
·3919-3924
·
IF 3.879
Suli Wu,Yanhui Ning,Jie Chang,Wenbin Niu,Shufen Zhang
Oleic acid together with sodium hydroxide (NaOH) was widely used to control the size, phase and morphology of NaYF4 UCNCs. However, reports are scarce about the modulation of the luminescence intensity and color output of NaYF4 UCNCs by using different amounts of NaOH. Here, we synthesized NaYF4:Yb3+, Er3+ nanocrystals by a hydro/solvent thermal method using oleic acid as ligand with different amounts of NaOH and systematically investigated their upconverted fluorescence spectra. The results indicated that the emission intensity of NaYF4 : Yb3+,Er3+, especially the green emission at 540 nm was dramatically increased as NaOH decreased. The enhancement factors of 540 nm emissions were 48, 42 and 32 for samples prepared with 0 g, 0.2 g and 0.4 g NaOH (the corresponding pH of the reaction solution were 5.9, 6.9 and 7.4), respectively, compared with that of the product prepared with the usually used 0.7 g NaOH (the corresponding pH was 8.3). Importantly, the ratio of green to red (RGR) increased from 0.4 to 5.9 when the pH decreased from 8.3 to 5.9. That is to say, the color output was tuned from orange yellow to nearly pure green. This resulted from the high energy vibration of OH−, which led to nonradiative relaxation from green emission levels (2H11/2 and 4S3/2) to the red emission level (4F9/2) and nonradiative relaxation from the red emission level (4F9/2) to the no emission level (4I11/2) of Er3+.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2016
·Vol. 3
·期 8
·1082-1090
·
IF 4.532
Min Li,Xiaoyang Liu,Li Liu,Bing Ma,Benxian Li,Xudong Zhao,Wenming Tong,Xiaofeng Wang
A series of Yb3+/Tm3+ co-doped β-NaYF4 (β-NaYF4:Yb,Tm) crystals have been successfully synthesized via the molten salt synthesis (MSS) method. A unique strong green emission of Tm3+ was observed, which cannot be obtained by any other method. The red, green and blue (RGB) light emissions have been obtained simultaneously in the presence of a single activator (Tm3+). The influencing factors of crystal growth have been studied in detail, in order to understand the change of the transition probabilities of Tm3+. Subsequent studies indicate that the RGB light emissions of Tm3+ can be effectively tuned by varying the concentration of sensitizers (Yb3+ and Mn2+) and the reaction time. Consequently, the effective multicolor upconversion (UC) luminescence was obtained, especially a strong white light, which was not obtained in the β-NaYF4:Yb,Tm system earlier. To our knowledge, it is the first time that the UC properties in the β-NaYF4:Yb,Tm system have been investigated by altering the transition probabilities at the same energy level of Tm3+.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 12
·125017
·
IF 1.449
Hanyu Yao,Honglie Shen,Quntao Tang
In this paper, Mn doped NaYF4:Er,Yb phosphors were successfully synthesized by a simple solvothermal method. According to the results of x-ray diffraction, scanning electron microscopy and photoluminescence measurement, Mn doping had a remarkable effect on the crystal phase, size, and especially upconversion (UC) properties of these phosphors. Under 980 nanometer (nm) laser excitation, the UC luminescence intensity could be enhanced by increasing Mn concentration. Temperature-dependence measurement of the samples from 300–30 K showed two green emission bands (2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of the Er3+ ion), which meant that the UC phosphors were suitable for temperature sensor by using the fluorescence intensity ratio (FIR) method. The FIR value decreased with temperature, and the experimental data were well fitted with a theoretical function. The higher maximum value of sensitivity (0.0057 K−1) for 20% Mn sample in contrast to that of 0% Mn one (0.0036 K−1) indicated that Mn doped sample had a higher sensitivity for temperature sensing. The results demonstrated that Mn doping would be a good way for optimizing the sensitivity of fluorescence-based temperature sensor.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2017
·Vol. 47
·期 5
·1666-1673
·
IF 4.029
Yan Lv,Lin Yue,Qian Li,Baoyi Shao,Sen Zhao,Haitao Wang,Shijia Wu,Zhouping Wang
Herein, the design and synthesis of a multifunctional (Fe3O4-NaYF4:Yb,Tm)@TiO2 photocatalyst through a facile sol–gel process combined with electrostatic self-assembly has been reported. Particularly, as an upconversion sensor, NaYF4:Yb,Tm nanoparticles have the ability to convert near-infrared (NIR) light into ultraviolet (UV) emissions, so that the catalytic body TiO2 can indirectly utilize the NIR part of sunlight but not UV light. The excellent photocatalytic activity of the hybrid samples is evaluated using a model of the degradation of methylene blue (MB). Most importantly, the obtained materials exhibit remarkable magnetic properties because of the addition of a magnetic component (Fe3O4), therefore, the photocatalysts possess desired recyclability and reusability, which is significant for actual applications. Finally, the possible photocatalysis mechanism of the nanohybrids is discussed and hydroxyl radicals (OH˙) are confirmed as the main reactive species.
研究领域:
材料科学
·
环境科学
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 29
·10299-10309
·
IF 4.39
Hailin Che,Peipei Dang,Yi Wei,Ziyong Cheng,Jun Lin
All-inorganic cesium lead halide (CsPbX3, X = Cl, Br, and I) perovskite quantum dots (PQDs) have great potential application due to their unique optoelectronic properties. However, poor luminescence stability caused by some inevitable factors such as light, moisture and heat always restricts their practical application. In this work, the stability of CsPbX3 (X = Cl0.5Br0.5, Br, and Br0.5I0.5) PQDs is improved by encapsulating them in stable hollow mesoporous NaYF4:Yb,Tm nanoparticles (HMNPs). Compared to pristine PQDs, HMNP–PQD composites exhibit stable photoluminescence properties that can be maintained for more than 60 days under ambient atmospheric conditions. Thanks to the protection of HMNPs, the composites show much higher long-term stability in highly humid air and enhanced stability against UV light treatment compared to naked CsPbBr3 PQDs. Based on the proposed confinement effects of PQDs coordinated with the hollow mesoporous structure of NaYF4:Yb/Tm, the related structural model of NaYF4:Yb/Tm@PQD composites is discussed. Moreover, dual-mode luminescence can be observed in the NaYF4:Yb/Tm@PQD nanocomposites under 365 nm UV light and 980 nm laser excitation, indicating that the as-designed composites have great potential for dual-mode anti-counterfeiting application. This work provides a new idea for the stabilization and application of CsPbX3 PQDs.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2014
·
IF 2.291
Xingyuan Guo,Changfeng Chen,Shengyan Yin,Weiye Song,Feng Shi,Weiping Qin.
In this work, the effects of NaYF 4 :Yb 3+ , Tm 3+ (NYT) structure on the near-infrared light (NIR) photocatalysis performance of ZnO were investigated. α-NYT/ZnO nanocomposites (NCs) and β-NYT/ZnO NCs were fabricated by a high temperature decomposition reaction method. The prepared NCs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis spectroscopy, Raman spectroscopy, and photoluminescence spectra (PL). The NIR photocatalytic activities of the synthesized α- and β-NYT/ZnO NCs were studied by the degradation of Rhodamine B. The differential photocatalytic activities between of α- and β-NYT/ZnO NCs are believed to be correlated to the effects of α- and β-NYT on the oxygen vacancies and exposed crystal face of ZnO.
研究领域:
材料科学
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
Optical Materials Express
·
2016
·Vol. 6
·期 4
·1056-1064
·
IF 2.657
Lili Huo,Jiajia Zhou,Ruozhen Wu,Junfei Ren,Shengjun Zhang,Junjie Zhang,Shiqing Xu
Hexagonal-phase NaYF4: Yb3+, Er3+ nanoparticles (NPs) have been widely used as the most efficient NIR-to-visible upconversion (UC) luminescent and probe in bioscience. Here, we exploited not only the function of dual-mode emission of β-NaYF4: Yb3+, Er3+ NPs in the near infrared (NIR) and visible regions with single wavelength excitation at 980 nm, but also the function of physiological temperature sensing with the luminescence of Er3+ in the visible region. The structural and optical characteristics of β-NaYF4: Yb3+, Er3+ NPs were obtained using X-ray diffraction (XRD), scanning electron microscopy (SEM),and fluorescence spectral measurements, respectively; the mechanism for the energy transfer has been suggested with emphasis on the optimized Er/Yb concentration for most efficient UC. Due to the UC and down-shifting NIR properties, we achieved the dual-functional nanoparticles with potential application in physiological range temperature sensing and bioimaging simultaneously.
研究领域:
生物医学工程
·
纳米技术
·
光学成像
✓ 已验证
产品关联
DOI
高影响因子
Small Methods
·
2025
·Vol. 9
·期 5
·2401615
·
IF 9.1
Leipeng Li,Huimin Li,Yifan Liu,Chongyang Cai,Pei Li,Dengfeng Peng,Yanmin Yang
Advanced functional materials that possess both persistent luminescence (PersL) and mechanoluminescence (ML) have gained considerable attention during the past few years owing to their potential applications in many fields such as two-dimensional stress sensing, energy-saving lighting, and optical bioimaging. However, combined investigation of PersL and ML is still in its infancy. Here, the optical property of Er 3+ -doped NaYF 4 , mainly focusing on the PersL and ML characteristic and their correlation, is studied in detail. It is shown that microscaled NaYF 4 :Er 3+ has advantages against nanoscaled counterpart in terms of PersL and ML, consistent with the photoluminescence results. By means of pre-charging and trap-emptying cycle and thermoluminescence test, it is confirmed that the PersL and ML of NaYF 4 :Er 3+ come from the same trapped charge carriers, and the ML belongs to the trap-controlled ML. Furthermore, the good repeatability is proven, and regulation of the PersL and ML of NaYF 4 :Er 3+ is realized. Finally, the potential of NaYF 4 :Er 3+ for dynamic anti-counterfeiting and dual-mode detection of X-ray radiation dose is demonstrated. Graphical After being charged by X-rays, NaYF 4 :Er 3+ emits green persistent luminescence and trap-controlled mechanoluminescence, which can be used for dynamic anti-counterfeiting and X-ray dosimetry.
研究领域:
材料科学
·
光学
·
固体物理
·
辐射探测
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Research Express
·
2023
·Vol. 10
·期 8
·086201
·
IF 2.3
Bing Liu,Jingheng Liang,Lili Wang,Zian Cheak Tiu
β-NaYF4: Yb3+/Tm3+/Zr4+ microcrystals are synthesized by a facile hydrothermal route. The up-conversion (UC) luminescence and photoelectric effects are enhanced simultaneously with the introduction of Zr4+ ions under IR excitation. With the Tm3+ ions fluorescence spectra under 980 nm excitation, the blue and red emissions reached the highest intensity in the case of 4 mol% Zr4+ doping. Taking the advantage of Zr4+ stimulates the free electrons transfer from the valence band (VB) to the conduction band (CB) in β-NaYF4:Yb3+/Tm3+/Zr4+ microcrystals, the photocurrent reached the highest intensity in the case of 4 mol% Zr4+ doping at 780 nm excitation. The β-NaYF4: Yb3+/Tm3+/Zr4+ microcrystals with both enhanced UC luminescence and photoelectric properties are highly potential to contribute in photovoltaic and infrared sensors application.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）