JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 6
·5735-5740
·
IF 1.798
Liu Chang,Liu Yunfei,Lyu Yinong,Lyu Chongguang
Octahedra-like NaNd(MoO 4 ) 2 microcrystals with tetragonal scheelite-type structure were successfully synthesized by a low cost molten salt method using halons (NaCl or NaBr) as flux. The as-prepared products were characterized by powder X-ray diffractometer, field emission-scanning electron microscope and photoluminescence spectrometer (PL). The results show that the reaction parameters including calcining temperature, reaction time, and the type of salt play important roles on the morphologies and sizes of the NaNd(MoO 4 ) 2 microcrystals. The excitation spectra of the NaNd(MoO 4 ) 2 octahedron-like crystals were observed with a maximum peak at 585 nm (λ em = 1066 nm). The emission spectra were recorded under excitation wavelength of 585 nm and exhibit the strongest peak at 1066 nm. In addition, the results revealed the size effect on the PL intensity of NaNd(MoO 4 ) 2 crystals, that the PL intensity of microcrystals is higher than that of nanocrystals. These imply that NaNd(MoO 4 ) 2 microcrystals have potential application in the field of solid state laser materials.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
BULLETIN OF MATERIALS SCIENCE
·
2024
·Vol. 47
·期 2
·1-10
·
IF 1.9
Ru Jingjing,Zhao Bing,Zeng Fan,Guo Feiyun
A set of colour tuning K 2 Ba(MoO 4 ) 2 : Dy 3+ /Eu 3+ (KBM: Dy 3+ /Eu 3+ ) phosphors were fabricated by solid-state method. The phase purity of as-prepared materials was validated by XRD and DRS analyses. The KBM: 0.03Dy 3+ sample exhibits two major luminescence lines at 481 and 572 nm when excited by 351 nm light, corresponding to Dy 3+ ions’ typical transitions of 4 F 9/2 → 6 H J (J = 15/2, 13/2). By introducing Eu 3+ ions into KBM: 0.03Dy 3+ phosphor, the ET from Dy 3+ to Eu 3+ ions arises, leading to colour tuning from green via yellowish green to pink with changing Eu 3+ ions’ concentration, along with the lowest CCT of KBM: 0.03Dy 3+ /0.03Eu 3+ sample. It can be verified by PLE and PL spectra analysis combined with the decay times of KBM: 0.03Dy 3+ /yEu 3+ samples. The energy transfer mechanism is also expounded. Meanwhile, the emission intensities at 423 K still maintain 72.8% for Dy 3+ ions and 91.2% for Eu 3+ ions relative to 303 K of the KBM: 0.03Dy 3+ /0.03Eu 3+ sample, displaying its brilliant thermal stability. All these results connote that KBM: Dy 3+ /Eu 3+ phosphors are prospected to be used for the near-UV excited white light-emitting diodes.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2020
·
IF 2.678
Tiantian Zhou,Haonan Zhang,Xiaoming Ma,Xin Zhang,Yuanna Zhu,Aiyu Zhang,Yongqiang Cao,Ping Yang
The AgI/Bi 2 MoO 6 /AgBi(MoO 4 ) 2 (ABM) multi-heterostructure nanosheet composite system for visible-light photocatalysis have been successfully constructed by a simple one-step calcination method. The ABM multi-heterostructure composite photocatalysts exhibited the obviously improved photocatalytic performance than the pristine Bi 2 MoO 6 , AgBi(MoO 4 ) 2 , and AgI for the degradation of both Tetracycline hydrochloride (TC) and Rhodamine B (RhB). The apparent degradation rate for the ABM sample with the highest photocatalytic activity is 5.4 (TC) and 23.4 times (RhB) that of Bi 2 MoO 6 , 4.0 (TC) and 4.9 times (RhB) that of AgBi(MoO 4 ) 2 , and 1.9 (TC) and 2.4 times (RhB) that of AgI, respectively. This ABM sample with the highest activity showed a Bi 2 MoO 6 /AgBi(MoO 4 ) 2 composite nanosheet morphology (lateral size: 1–5 u m, thickness: 90−130 nm) with a large amounts of small AgI nanocrystals (diameter: 2−25 nm) uniformly distributed on the surface of composite sheet. The outstanding performance of the ABM composite photocatalysts should be ascribed to the effective separation of photoinduced electron-hole pairs via the multi-heterostructure in ABM, the enhanced visible-light absorption, as well as the two-dimensional (2D) morphology benefitting to the exposure of plenty of surface reactive sites and significant reduction of migration distances of photogenerated carriers. It is hoped that this facile method for the fabrication of multi-heterostructure in our work could promote and inspire the other multicomponent functional nanomaterials used in the fields of not only photocatalysis, but also solar cells, sensors, catalysis, and so on, in the future.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS
·
2020
·
IF 1.771
Yuejun Li,Tieping Cao,Zemin Mei,Xiaoping Li,Dawei Sun
Among tremendous efforts for enhanced photocatalysis, construction of heterojunction has been deemed as an effective means. In comparison with type II heterojunction, type I heterojunction receives less attention due to accumulation and increased recombination of charge carriers in one side of heterojunction. Herein, we take NaBi(MoO 4 ) 2 /Bi 2 MoO 6 as an example of type I heterojunction and explore means to improve the photocatalytic performance of NaBi(MoO 4 ) 2 /Bi 2 MoO 6 heterojunction. We employ TiO 2 electrospun nanofibers as substrates and separately grow NaBi(MoO 4 ) 2 and Bi 2 MoO 6 nanostructures on the skeleton of TiO 2 . The characterization results show that TiO 2 changes type I heterojunction into multiheterojunction integrating two type II heterojunctions. Photocatalytic tests demonstrate that as-constructed multi-heterojunction is of higher activity than that of single type I or II heterojunction, respectively, where photogenerated electrons are accumulated on the surface of TiO 2 and photogenerated holes are accumulated on NaBi(MoO 4 ) 2 and Bi 2 MoO 6 , respectively. This study highlights the potential application of TiO 2 electrospun nanofibers in the construction of multiheterojunction for enhanced visible light photocatalysis.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 57
·45693-45702
·
IF 3.84
Anming Li,Dekang Xu,Hao Lin,Shenghong Yang,Yuanzhi Shao,Yueli Zhang,Zhenqiang Chen
Well-crystallized and uniform NaGd(MoO4)2 microcrystals with morphologies of bipyramids, truncated bipyramids, quasi-cubes and tetragonal plates were selectively synthesized via a facile hydrothermal method without any additives under mild conditions. The effects of Na2MoO4/Gd(NO3)3 molar ratios and pH values of precursor solutions on the phase and morphology of the as-synthesized microcrystals were systematically investigated. The molar ratios and pH values played key roles in the selective synthesis of pure phase NaGd(MoO4)2 microcrystals with regular morphology. With increasing Na2MoO4/Gd(NO3)3 molar ratios in the appropriate pH range, the morphology of the products changed from bipyramids, truncated bipyramids, quasi-cubes to tetragonal plates, namely, the morphological truncation degree increased gradually. NaGd(MoO4)2 tetragonal microplates could be synthesized at the molar ratio of 9 : 1. A possible morphological formation mechanism of NaGd(MoO4)2 tetragonal microplates was proposed, i.e. nucleation-Ostwald ripening growth process. Color tunable photoluminescence properties of NaGd(MoO4)2:Eu3+,Tb3+ microcrystals were studied in detail. Among the different morphologies of NaGd(MoO4)2:5% Eu3+ microcrystals, tetragonal microplates had a broadened, red-shifted and enhanced charge transfer band in the excitation spectrum. What's more, the full-width at half-maximum for the charge transfer band of the tetragonal plates was highest (58 nm), which favored efficient excitation and absorption in the ultraviolet region. The introduction of a small amount of Tb3+ into NaGd(MoO4)2 microplates doped with Eu3+ would enhance the 5D0 → 7FJ transition of Eu3+ at 616 nm due to the energy transfer process of cross-relaxation from Tb3+ to Eu3+. Multicolor tunable luminescence from deep red, red, orange, yellow to green under 291 nm ultraviolet excitation and from red, reddish orange to pink under 380 nm near-ultraviolet excitation could be obtained in NaGd(MoO4)2 tetragonal microplates by simply adjusting the doping concentrations of Eu3+ and Tb3+, suggesting NaGd(MoO4)2:Eu3+,Tb3+ microcrystals might have practical application in optoelectronic devices, such as light emitting diodes and color display systems. This facile morphology-controlled hydrothermal synthesis strategy was simple, low-cost and environment-friendly, and might be extended to other inorganic materials.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 5
·6239-6248
·
IF 2.478
Fan Wenli,He Youyi,Long Lizhen,Gao Yalei,Liu Fuchi,Liu Jun
To research and develop the potential red emission phosphors for warm white-light-emitting diodes (WLED), we systematically investigated double alkaline rare-earth molybdates KGd 1− x Eu x (MoO 4 ) 2 (0.05 ≤ x ≤ 1) phosphors. The crystal structure, morphology, chemical composition, and photoluminescence properties of the phosphors with different Eu 3+ doping concentrations were investigated in detail. The results indicate that Eu 3+ doping concentration can affect the crystal structure and morphology of KGd 1− x Eu x (MoO 4 ) 2 phosphors. The luminescence performance reveals that KGd 1− x Eu x (MoO 4 ) 2 phosphor could emit intense red emission under multiplexed excitations at 362, 382, 394, 465, and 535 nm, which are matched well with the commercial UV, blue and green LED chips. An abnormal quenching behavior was observed in the KGd 1− x Eu x (MoO 4 ) 2 phosphors. And the quenching behavior at the excitation of Eu 3+ –O 2− Charge-Transfer band and Eu 3+ ions 4 f –4 f transitions is quite different. Finally, we fabricated a WLED lamp by coating the InGaN blue chip with a mixture of YAG: Ce 3+ yellow phosphors and KEu(MoO 4 ) 2 red phosphors. The obtained WLED lamps showed warm white light with a lower CCT value (~ 5142 K) than that fabricated without the red phosphors (CCT = 5892 K). These results proved that the KGd 1− x Eu x (MoO 4 ) 2 could be a very promising red-emitting phosphor for WLED.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 103
·期 2
·1046-1056
·
IF 3.094
Xiaohui Feng,Le Wang,Ran Wei,Ziyan Wang
Non-contact temperature sensors based on the fluorescence intensity ratio (FIR) have been widely investigated owing to their high sensitivity and reliable real-time monitoring. Herein, the SiO 2 -coated LiY(MoO 4 ) 2 @SiO 2 :Er 3+ ,Yb 3+ phosphor was investigated as an optical thermometry material, which was synthesized using the conventional solid state reaction and coated by a facile wet chemical route. The effect of surface modification on FIR was systematically characterized by structural analyses and spectral measurements and the temperature-dependent up-conversion FIR was investigated from 303 to 603 K under a 980 nm laser excitation. The results showed that the FIR value was thermally stable and the SiO 2 coating led to a higher FIR sensitivity as well as a higher saturation threshold. This work would pave a way to design interesting optical thermometry materials in up-conversion phosphors with better properties.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 18
·1251
·
IF 2.8
Zheng Jinjie,Shen Honglie,Li Yufang,Li Hechao,Yue Zhen
Novel efficient visible and near-infrared emitting phosphors NaY(MoO 4 ) 2 (NYM):Ln 3+ (Ln = Ce and Yb) were proposed in this work. The crystal structure, lattice vibration characteristics, morphology, and luminescent properties of NaY(MoO 4 ) 2 phosphors were described. Sensitization of Ln 3+ from the host with various doping concentrations was investigated. The yellow-green emission was achieved in Ce 3+ single-doped NYM phosphors at UV ultraviolet excitation sensitized by the MoO 4 2− group. Under UV excitation, characteristic emissions of Ce 3+ at 400–700 nm and Yb 3+ at 1000 nm of NYM:Ce,Yb were observed, enabling the spectral down-conversion applications. With the increasing concentration of Yb 3+ , the emission intensity as well as the lifetime of Ce 3+ decreased, confirming the energy transfer from Ce 3+ ions to Yb 3+ ions. And the energy transfer coefficient was 27% for NYM:0.01Ce,0.10Yb phosphor. These results indicate that the as-prepared phosphors have potential applications in optical and photonic devices.
研究领域:
材料科学
·
光学材料
·
发光学
·
无机化学
·
光子学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Shiying Tan,Xusheng Wang,Yan Zhao,Yanxia Li,Xi Yao
Rare earth doped upconversion luminescent materials have the advantages of low toxicity, high chemical stability, excellent photostability, narrow emission band, and long luminescent life, but their low fluorescence quantum efficiency restricts their practical application in the field of temperature sensing. In this paper, Er 3+ doped KYb(MoO 4 ) 2 (KYM) phosphors were synthesized by a temperature solid state reaction method. When the doped concentration is 5 mol%, the luminescence intensity get its strongest value. On this basis, 2 mol% trivalent ions Gd 3+ , La 3+ and Y 3+ (R 3+ ) were doped respectively, and the luminescence intensity increased by about 2 times. By the fluorescence intensity ratio technique, the KYM:5Er phosphor has the maximum absolute temperature sensitivity of 0.0106 K -1 . By codoping 2 mol% Gd 3+ in KYM:5Er, the upper limit of temperature measurement increased from 513 K to 663 K, which shows that Er 3+ -doped and Er 3+ /R 3+ -codoped KYM have the potential as temperature sensors .
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2020
·Vol. 22
·期 19
·3361-3370
·
IF 3.117
Yini Mao,Li Jiang,Pengfei Xian,Qiongfen Fu,Shanshan Hu,Jun Yang
A graphical abstract is available for this content
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
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.
研究领域:
材料科学
·
光学
·
发光材料
·
温度传感
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Anming Li,Zhaohan Li,Lijun Pan,Zhiwen Wang,Weiguang Chen,Qinqin Shao,Bingjie Wu,Yanan Tang
Multifunctional upconversion luminescent nanoheaters are realized based on NaGd(MoO 4 ) 2 :Yb 3+ /Tm 3+ nanocrystals synthesized by surfactant-free solvothermal method. The structure, morphology and composition of the nanocrystals are analysed by XRD , SEM, EDS , TEM, HRTEM and SAED techniques. Under 980 nm irradiation, NaGd(MoO 4 ) 2 :Yb 3+ /Tm 3+ nanocrystals emit blue luminescence with emission peaks located in the blue and near-infrared spectral regions. The electronic transition processes for the upconversion luminescence are discussed based on the excitation power-dependent upconversion luminescence, luminescent dynamics and Yb 3+ /Tm 3+ energy levels. The nanocrystals show efficient photothermal conversion after irradiated by 980 nm laser. The photothermal conversion slope efficiency for NaGd(MoO 4 ) 2 :Yb 3+ /Tm 3+ nanocrystals irradiated by 980 nm laser for 10 s duration is 17.43 °C/W for 10 mol% Yb 3+ doping and 43.64 °C/W for 15 mol% Yb 3+ doping. Multifunctional luminescent nanoheater NaGd(MoO 4 ) 2 :Yb 3+ /Tm 3+ nanocrystals exhibit both upconversion photoluminescence and photothermal conversion capabilities, and are promising candidates for temperature self-monitoring photothermal therapy or other biological applications.
研究领域:
材料科学
·
生物医学工程
·
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）