APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2022
·Vol. 128
·期 8
·1-11
·
IF 2.983
Chen Zhangxu,Zhu Danchen,Zhang Lidan
To overcome the intrinsic disadvantages of pristine g-C 3 N 4 and make it reusable, improve the activity of g-C 3 N 4 by making use of the near-infrared region, the magnetic Fe 3 O 4 /β-NaYF 4 /g-C 3 N 4 (FO/UC/CN) heterogeneous materials with high and stable NIR enhanced photocatalytic activity were prepared via a new facile one-step solvothermal synthesis method. It can be revealed that FO/UC/CN can activate UV–visible light under excitation of 980 nm. Compared with pure Fe 3 O 4 , g-C 3 N 4 and Fe 3 O 4 /g-C 3 N 4 , the obtained FO/UC/CN15 heterojunction exhibits good photodegradation rates of 65.56, 21.35, 59.22 and 20.49% for MB, MO, RhB and phenol, respectively. In addition, after four cycles of the photocatalytic degradation test, the photodegradation rates remain 62.14, 20.54, 57.64 and 19.36%, respectively. The results illustrate magnetic FO/UC/CN heterojunction exhibits highly NIR-enhanced photocatalytic activity and excellent stability. This study indicates a promising system to synthesize g-C 3 N 4 -based magnetic photocatalysis for effectively utilizing the NIR and treating industrial wastewater, which can be expected to alleviate the energy crisis and enhance the application of solar energy for dealing with environmental remediation in the future.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 8
·8254-8270
·
IF 1.798
Xi Junhua,Ding Mingye,Dai Jianbin,Pan Yajing,Chen Daqin,Ji Zhenguo
In this paper, Yb 3+ /Er 3+ co-doped hexagonal NaYF 4 have been successfully synthesized by solvothermal, thermal decomposition, hydrothermal and molten salt method, respectively. The crystal structures, particle morphologies, sizes and corresponding upconversion luminescent properties of β-NaYF 4 :Yb 3+ /Er 3+ nano/microcrystals are systemically studied. It is interesting to observed that the temperature-dependent UC luminescent properties of β-NaYF 4 :20 %Yb 3+ , 2 %Er 3+ samples are strongly related to their synthesis methods. Comparison of the upconversion luminescence and thermal sensitivity between the β-NaYF 4 :Yb 3+ /Er 3+ samples reveals that β-NaYF 4 :Yb 3+ /Er 3+ sub-microplates synthesized by thermal decomposition method have much stronger green emission intensity, better luminescent thermal stability and higher temperature sensitivity. This findings are relevant to the application of β-NaYF 4 :Yb 3+ /Er 3+ in optical temperature sensors and to the further understanding of the UC luminescent mechanism.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2018
·Vol. 44
·期 10
·6369-6385
·
IF 1.674
Chen Zhangxu,Fu Ming-Lai,Huang Xiao-Dan,Yuan Baoling,Yang Jia-Cheng E.
To enhance photocatalytic activity spectra area of the TiO 2 based photocatalyst, and to separate and recycle photocatalyst easily, magnetic photocatalyst was prepared with β-NaYF 4 :Yb 3+ ,Tm 3+ , TiO 2 , Fe 3 O 4 as carriers, and tetraethyl orthosilicate as precursor. The magnetic infrared responsive photocatalysts were thoroughly characterized by field emission scanning electron microscopy, X-ray diffraction, a fluorescence spectrometer and UV–Vis–NIR diffuse reflectance spectroscopy. They showed that the composite of β-NaYF 4 :Yb 3+ ,Tm 3+ /TiO 2 /Fe 3 O 4 @SiO 2 (UCTFS) emits visible luminescence upon 980 nm excitation, and energy transfer from β-NaYF 4 :Yb 3+ ,Tm 3+ to TiO 2 was verified. The photocatalytic activities of the UCTFS were studied by orthogonal experiments for photodegradating methylene blue (MB). The degradation rate of MB can reach 86.69% under the optimal conditions. After the four recycles, the degradation rate remained 52.72%. It also showed that 50.27% of the degradation efficiency of phenol can be obtained under the same experimental parameters. These results suggest that magnetic UCTFS composite is stable and a magnetic NIR-driven photocatalyst for degradation of organic pollutants. Moreover, the NIR driven photocatalytic mechanism of this reported composite was proposed. The strategy suggested here may be indicated for the effective fabrication of magnetic NIR-driven photocatalyst for application in the water purification by full spectra of solar energy.
研究领域:
材料科学
·
环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2018
·
IF 2.873
Song Ye,Ping Xiao,Huazhen Liao,Song Li,Deping Wang
We developed a facile approach for the fast synthesis of ultrasmall and monodisperse β-NaYF 4 :Yb 3+ , Er 3+ nanocrystals down to 5.3 nm with the assistant of oleate ligands, based on which the highly bright sub-10 nm β-NaYF 4 :Yb 3+ , Er 3+ @NaYF 4 core-shell nanocrystals with three order of magnitude increased upconversion emission were successfully obtained by a seed-mediated growth method. The reaction time and temperature dependent experimental results implied that the introduciton of extra oleate ligands can both promote the α-to-β phase transition and impeded the crystal growth of NaYF 4 , which is due to the oleate ligand induced orderly arrangement of Y 3+ and capping effect, respectively. It is expected that the oleate ligands mediated phase transition and size evaluation, demonstrated here in NaYF 4 :Yb 3+ , Er 3+ NCs, is also applicable to other lanthanide-doped upconversion nanocrystals.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
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.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Hao Tang,Hua Zhou,Xianhua Cheng
The green and red upconversion (UC) emissions of 35 mol% Ca 2+ doped β-NaYF 4 :Yb 3+ /Er 3+ microcrystals were improved to 102.8 and 43.1 times higher than those of Ca 2+ -free counterparts. X-ray powder diffraction spectra, scanning electron microscopy, Fourier transform infrared spectroscopy , upconversion luminescence (UCL) spectroscopy and Judd-Ofelt analysis were performed to investigate the mechanism of UCL intensity enhancement caused by Ca 2+ doping. The hexagonal-to-cubic phase transition was observed when Ca 2+ doping concentration exceeded 35 mol%. The incorporation of Ca 2+ into hexagonal microcrystals lattice induced unit cell volume enhancement and microcrystals surface to volume ratio variation, which affected the UCL intensity by hindering the non-radiative energy loss process via Yb 3+ /Er 3+ ions and changing the amount of surface quenchers adsorbed on the microcrystals surface. The hypersensitive transition related local crystal field asymmetry around Er 3+ in the grown hexagonal microcrystals was also investigated by Judd-Ofelt analysis but unexpectedly found to be the less dominant factor for the UCL intensity variation. This study helps to realize the mechanism of impurity ion doping resulted UCL intensity enhancement, which is instructive for high-performance UC microcrystals synthesis.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Mingye Ding,Chunhua Lu,Le Chen,Zhenguo Ji
Traditional FIR (fluorescence intensity ratio)-based optical thermometers, requiring narrow energy gap between two thermally coupled states (TCS) of single rare-earth ion, have inherent drawbacks including low signal discriminability and large measuring error. To overcome the intrinsic limitation, a new thermometry strategy involving the usage of dual-emitting activators with diverse temperature-dependent emission behaviours has been proposed. Impressively, β-NaYF 4 :Ce 3+ /Tb 3+ phosphor exhibits good temperature sensing performance, excellent signal discriminability and superior thermal stability by using the linearly temperature-dependent FIR between Ce 3+ and Tb 3+ as detecting parameter. Hopefully, the developed dual-emitting sample could have a promising application in self-calibrated luminescent thermometry and this strategy provides a reference for developing high-performance optical thermometers.
研究领域:
材料科学
·
光学工程
·
无机化学
·
生物医学工程
·
纳米技术
·
传感器
✓ 已验证
DOI
高影响因子
Journal of Nanomaterials
·
2012
·
IF 1.376
Suli Wu,Yanhui Ning,Shufen Zhang
Novel chelating ligands are very significant for preparing nanocrystals with different morphologies and applications. In this paper, we directly introduced amine groups onto UCNPs by choosing a new chelating ligand tetraethylene pentamine (TEPA) to synthesis
N
a
Y
F
4
:Yb, Er through hydrothermal method. The influences of rare earth concentration, the ratio of RE/TEPA, solvent composition, and reaction time on the morphology and fluorescence intensity of the as-prepared
N
a
Y
F
4
:Yb, Er samples were systematically investigated and discussed. Field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD), and upconversion luminescence spectroscopy were used to characterize the product. It was found that rare earth concentration, ratio of RE/TEPA, solvent composition, and reaction time were all responsible for the luminescent intensity and morphology.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
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.
研究领域:
纳米材料科学
·
生物医学工程
·
光学材料
✓ 已验证
产品关联
DOI
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.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Yiran Jiao,Yuan Pu,Jie-Xin Wang,Dan Wang,Jian-Feng Chen
We reported the process intensified synthesis of β-NaYF4 nanorods based on the traditional hydrothermal methods. A high-gravity rotating packed bed (RPB) reactor was used to intensify the mass transfer and micromixing of the precursors for critical nuclei. The proposed high gravity RPB assisted strategy is easy-to-perform for scale-up. The influence of reaction conditions was explored and the possible mechanism of the formative of β-NaYF4 nanorods was discussed. Accordingly, over 1 g of pure β-phase NaYF4:Gd3+/Yb3+/Er3+ nanorods with well-defined morphology and structure were prepared via one batch reaction. The rare-earth doped β-NaYF4 nanorods are highly dispersible in organic solvents with intense upconversion luminescence under near-infrared (NIR) light irradiation. The translucent NIR detector card of nanocomposites of poly(methyl-methacrylate) and the nanoroads was fabricated accordingly. The photosensitive region can also be activated by illuminating the back of the card, which is useful when aligning two beams to overlap.
研究领域:
材料科学
·
纳米技术
·
化学工程
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2019
·
IF 2.291
Ping Xiao,Song Ye,Huazhen Liao,Yanling Shi,Deping Wang
The ability to increase the emission intensity and turn the emission color of upconversion nanocrystals (NCs) will greatly enhance their application scopes. In this research, the sub-10 nm pure β-NaYF 4 : Yb 3+ /Tm 3+ /Ho 3+ core NCs were prepared by using sodium oleate (NaOA) as sodium source instead of the traditional NaOH, based on which the β-NaYF 4 :Yb 3+ /Er 3+ @NaYF 4 core-shell NCs were successfully obtained with seed-mediated growth method. The spectral measurement and the calculated CIE color coordinates revealed that the growing of inert NaYF 4 shell on the active NaYF 4 : Yb 3+ /Tm 3+ /Ho 3+ core NCs can not only effectively increase the upconversion emission intensity, but also realize extended tunable emission from blue to orange by turning Ho 3+ concentration, and a strong white light emission with chromaticity coordinates of (0.32, 0.33) can be obtained in the NaY 0.77 F 4 :0.2Yb 3+ /0.01Tm 3+ /0.02Ho 3+ @NaYF 4 core-shell NCs. Furthermore, the extended color tunability and efficient white white-light generation in the core-shell NCs were demonstrated by NCs-PMMA nanocomposites under 980 nm excitation. The results suggested that the β-NaYF 4 :Yb 3+ /Er 3+ @NaYF 4 core-shell NCs have promising applications in optoelectronic devices such as light emitting diode and three-dimensional display.
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）