Advanced Optical Materials
·
2024
·Vol. 12
·期 19
·2400250
·
IF 8
Wenyu Tang,Yuanjing Wang,Yayun Zhou,Chuang Zhang,Zhen Chen,Fanquan He,Enhai Song,Qinyuan Zhang
Mn 4+ -activated red-light fluorides are widely used in high-quality displays, due to the narrow-spectral emission. However, achieving exceptional chromaticity coordinates and appropriate quantum efficiency (QE) at the same time is a great challenge. Herein, a Li substitution strategy is proposed for enhancing QE and improving the thermal stability of red-light Mn 4+ -activated Cs 2 NaGaF 6 (CNGF). The external quantum efficiency (EQE) of optimal Cs 2 NaGaF 6 : Mn 4+ , Li + (CNGF: Mn 4+ , Li + ) is improved from 15.79% to 33.61% and thermal stability increases from 68.4% to 85.5% (intensity at 150 °C relative to room temperature). EQE enhancement mechanism on the strategy is explored that Li substitution increases the local structural distortion of Mn 4+ for relieving the parity forbidden, and promotes Mn 4+ doping in the host lattice, which provides new insights for improving the QE of Mn 4+ non-equivalent doped fluorides. Moreover, with exceptional chromaticity coordinates of (0.7029, 0.2970), optimal sample CNGF: 4.8 mol% Mn 4+ ,0.9 mol% Li + can be used to fabricate white light-emitting diode (w-LED) backlight, which obtains wide color gamut of 110.68% National Television Standards Committee (NTSC) and high luminous efficacy of 110.57 lm W −1 , indicating that CNGF: Mn 4+ , Li + is a promising candidate for the next generation of wide gamut and efficient displays.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Bin Li,Yingfang Li,Bin Cao,Chong Yang,Rongbo Ma,Chaoyong Deng,Weichao Huang
The high-temperature solid-state method synthesized novel double perovskite CaSrLaSbO 6 : Bi 3+ , Mn 4+ phosphors. Its crystal structure, luminescence properties, crystal field strength, energy transfer process, and temperature-sensitive properties were comprehensively investigated. The band gap values of CaSrLaSbO 6 were calculated using density functional theory. In the CaSrLaSbO 6 host, Bi 3+ exhibits multiple emission properties in the violet, blue, and NIR regions due to the 3 P 1 → 1 S 0 transition, while the red emission is due to the 2 E g → 4 A 2g transition of Mn 4+ . Light-converting films fabricated using CaSrLaSbO 6 :Bi 3+ , Mn 4+ under 302 nm UV excitation with multiple emissions showed significant plant growth promotion. In addition, the optical temperature-dependent response of CaSrLaSbO 6 : Bi 3+ , Mn 4+ was analyzed using the luminescence intensity ratio technique, and the relative sensitivity of the best samples reached 2.1 % K −1 . The above results indicate that CaSrLaSbO 6 : Bi 3+ , Mn 4+ provides almost all the light sources necessary for plant growth and can be applied in the field of optical temperature sensors, which shows that this multifunctional phosphor has great potential for application.
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高影响因子
MOLECULAR PHARMACEUTICS
·
2024
·
IF 4.5
Hong-Ying Xia,Ying Zhao,Ruo-Yin Meng,Ai-Zheng Chen,Shi-Bin Wang,Ranjith Kumar Kankala
Despite the advancements in cancer therapy, delivering active pharmaceutical ingredients (APIs) using nanoparticles remains challenging due to the failed conveyance of the required drug payload, poor targeting ability, and poor biodistribution, hampering their clinical translation. Recently, the appropriate design of materials with intrinsic therapeutic functionalities has garnered enormous interest in the development of various intelligent therapeutic nanoplatforms. In this study, we demonstrate the fabrication of transition metal (molybdenum, Mo)-doped manganese dioxide (MnO2) nanoarchitectures, exhibiting diagnostic (magnetic resonance imaging, MRI) and therapeutic (chemodynamic therapy, CDT) functionalities. The facile hydrothermal approach-assisted Mo-doped MnO2 flower-like nanostructures offered tailorable morphologies in altered dimensions, precise therapeutic effects, exceptional biocompatibility, and biodegradability in the tumor microenvironment. The resultant defects due to doped Mo species exhibited peroxidase and oxidase activities, improving glutathione (GSH) oxidation. The two sets of variable valence metal ion pairs (Mn2+/Mn4+ and Mo5+/Mo6+) and their interplay could substantially improve the Fenton-like reaction and generate toxic hydroxyl radicals (•OH), thus achieving CDT-assisted antitumor effects. As inherent T1-MRI agents, these MnO2 nanoparticles displayed excellent MRI efficacy in vitro. Together, we believe that these conformational Mo-doped MnO2 nanoarchitectures with two pairs of variable valence states could potentiate drugless therapy in pharmaceutics.
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PubMed
高影响因子
Solids
·
2025
·Vol. 6
·期 4
·66
·
IF 2.4
Chenxing Liao,Feng Zhou,Wei Xie,Liaolin Zhang
Mn4+-doped fluoride red phosphors are widely used in white LED lighting and display applications due to their excellent luminescent properties. However, their synthesis relies heavily on highly toxic aqueous hydrofluoric acid, which not only causes severe environmental and soil/water pollution but also makes it difficult to control the microstructure of the products due to the rapid reaction rate. In this study, low-melting-point NH4HF2was used as the molten salt, with KMnO4and MnF2as manganese sources, to synthesize the red phosphor K3AlF6: Mn4+via the molten salt method. After the reaction, impurities such as NH4HF2were removed by washing with a dilute H2O2solution. The microstructure, photoluminescence properties, thermal quenching behavior, and application in warm white light-emitting diodes (W-LEDs) of the K3AlF6: Mn4+phosphors were investigated. The results indicate that the phosphors prepared by this method consist of a single pure phase. By adjusting the molten salt content, the morphology of the product can be transformed from nanoparticle-like to nanorod-like structures. All products exhibit the characteristic red emission of Mn4+under blue and violet light excitation, with the optimally doped sample achieving an internal quantum efficiency (IQE) of 69% under blue light excitation. The combination of the obtained K3AlF6: Mn4+with the yellow phosphor YAG enabled the fabrication of W-LEDs. These W-LEDs achieved a color rendering index (Ra) of 86.8, a luminous efficacy (LE) of 77 lm/W, and a correlated color temperature (CCT) of 3690 K, along with excellent color stability under operating conditions.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 38
·17984-17998
·
IF 3.3
Si Duan,Guihong Lan,Xiaoting Yang,Yongqiang Liu,Haiyan Qiu,Bo Xu,Yuan Gao,Zhuang Xie
Antibiotic contamination has become one of the most pressing problems in the field of water purification. Using nano-graphite (nano-G) as a carbon carrier, a ZrO2–MnOx/nano-G composite electrode with high catalytic activity was prepared by a hot pressing method based on MnOx/nano-G prepared by a sol–gel method. The results showed that the ZrO2–MnOx/nano-G electrode reduces charge transfer resistance while improving surface oxygen desorption ability. MnOx can catalyze the two-electron reduction of O2 to produce H2O2, which can then be converted to ˙OH and ˙O2−. Thereafter, the results of free radical capture experiments confirmed that ˙O2− played a significant role in the electrocatalytic degradation of tetracycline hydrochloride (TC) by a ZrO2–MnOx/nano-G composite electrode. Furthermore, the abundant hydroxyl groups on the surface of nano-G and ZrO2 particles can be used as active sites for catalyzing the Mn3+/Mn4+ redox reaction, resulting in the generation of additional free radicals. The high-efficiency electrocatalytic degradation of TC was achieved through the synergistic action of the three. Under optimal reaction conditions, the degradation rate of TC reached 93% after 120 min of electrolysis. ZrO2–MnOx/nano-G displayed satisfactory stability following 10 cycles of degradation experiments. Finally, the potential TC degradation pathway was investigated using liquid chromatography-mass spectrometry (LC-MS) and density functional theory (DFT), and the degradation mechanism was clarified.
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高影响因子
Journal of Materials Chemistry C
·
2024
·
IF 5.7
Qiao Qu,Haiyan Zhang,Haipeng Ji
The parity-selection rule for the Mn4+ d→d intra-configurational transition, if being relaxed, would generate Mn4+-doped red-emitting phosphor with short fluorescence lifetime, a desired feature when a phosphor is used in a white light-emitting diode (WLED) lamp applied as backlight in displays. We design non-equivalent substitution of Mn4+ for Mo6+ coordinated with F−/O2− mixed-anions, and obtained K3Na(MoO2F4)2·H2O:Mn4+ red phosphor which exhibits fast decay (luminescence lifetime of ~2 ms) and intense zero phonon line (ZPL) emission at 623 nm (ZPL/ν6 intensity ratio of 65.7% at 300 K) under 470 nm excitation. The local octahedron distortion accounting for the luminescence features was discussed and the crystal field strength and nephelauxetic effect were compared with analogues. The increasing trend of the ZPL/ν6 intensity ratio from 300 K to 80 K was explained, and the luminescence decay of a series of Mn4+ doping concentrations was studuied. The K3Na(MoO2F4)2·H2O:3%Mn4+, when encapsulated with garnet green phosphor on a blue LED, produced a WLED backlight with a wide color gamut above 103.5% of the NTSC standard.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 23
·27513-27523
·
IF 2.478
He Youyi,Liu Jun,Gao Yalei,Yan Lijuan,Lv Fengzhen,Liu Fuchi,Long Lizhen
Mn 4+ -activated phosphors have become a hotspot in the development of inorganic red phosphors due to the fascinating photoluminescent properties. Herein, the synergetic manipulation of the flux effect and charge compensation was employed to improve the performance of Mn 4+ -activated CaAl 12 O 19 red phosphors. The crystallinity was improved by appropriate Zn 2+ -doping, while nonradiative transition between Mn 4+ ions is reduced by charge compensation of the formation of Mn 4+ –Mg 2+ pairs with Mg 2+ dopants. Thus, the emission of Mn 4+ -activated CaAl 12 O 19 red phosphors has been remarkably enhanced. The low probability of nonradiative transition between Mn 4+ ions was demonstrated by the thermal stability analysis. To depict the luminescent process, the crystal-field strength ( D q ), and Racah parameters ( B and C ) were calculated to determine the sequence of the energy levels. Meanwhile, the warm WLEDs with high CRI and low CCT were obtained using the prepared phosphors as red-emitting composition. Our results clearly suggested that the synergetic strategy by combining the flux effect and charge compensation is an effective method to enhance the luminescence of CaAl 12 O 19 :Mn 4+ , and CaAl 12 O 19 :Mn 4+ /Zn 2+ /Mg 2+ red-emitting phosphors, which have potential application value in warm WLEDs.
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高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 44
·16421-16432
·
IF 4
Xiaoyi Liu,Haiming Cheng,Hu Wang,Zhu Wen,Guixia Liu,Shengda Liu,Dan Li,Jinxian Wang,Wensheng Yu,Xiangting Dong
Herein, a new organic cationic matrix [N(CH3)4]3MoO3F3 suitable for Mn4+ doping was constructed. Due to the large steric hindrance of N[CH3]4+ (TMA), charge compensation defects can be effectively prevented in the heterovalent Mn4+-doping process, and a high IQE (91.05%) was obtained. Through the cation co-doping strategy, Mg2+/Zn2+/Li+ cations were introduced into the Mo6+ cationic site, which improved the crystallinity of the matrix and reduced energy losses, so as to improve luminescence intensity, QE, thermal stability, water stability and other spectral properties. Meanwhile, [N(CH3)4]2TiF6:Mn4+ phosphors with the same TMA organic cation and equivalent Mn4+ doping were synthesized for comparison, and the effects of the Mg2+ cation co-doping strategy on the spectral properties of phosphors with different matrix types (fluoride/oxyfluoride) and substitution types (equivalent/non-equivalent) were analyzed. These findings provide the basis for the preparation of new luminescent materials. Furthermore, according to the optical properties exhibited by these phosphors, they are packaged into WLED devices with excellent photoelectric properties, which are suitable for indoor lighting and display fields.
研究领域:
材料科学
·
光学
·
光子学
·
发光材料
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高影响因子
JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Qijian Zhu,Jiansheng Huo,Liguo Zhang,Jinwei Gao,Qianming Wang
Green photosynthetic pigments play a major role in light-harvesting for biological substances and bio-mimetic strategy will provide a structural or functional model for natural antenna system . But the precise supramolecular structure of chlorosome has still not been clearly identified and the simulation of its function with new alternatives will be a real challenge. It has been well accepted that blue and far-red light are responsible for photosynthesis and photomorphogenesis in the process of plant growth. In this work, a series of single-composition LiLa 2 SbO 6 (abbreviated as LLSO): x Bi 3+ , y Mg 2+ , z Mn 4+ phosphors with double perovskite‐type structure and the evaluation as blue and far-red dual-emission light for plant growth light-emitting diodes (LEDs) have been reported via a high-temperature solid-state reaction method. Under near ultraviolet-light ( n -UV) excitation at 355 nm, intense blue emission (ranging from 360 to 500 nm, 3 P 1 → 1 S 0 ) from Bi 3+ and far-red emission (650–750 nm, 2 E g → 4 A 2g ) from Mn 4+ are found in Bi 3+ -Mn 4+ co-activated LLSO phosphors. To further optimize the photophysical properties, smaller Mg 2+ has been incorporated into Li + site in Bi 3+ -doped LLSO phosphor to control blue emission of Bi 3+ . With the increase of Mg 2+ content, an obvious red shift (~15 nm) of Bi 3+ emission band has been detected in the blue region, which is almost overlapped with the absorbance of Chlorophyll- B (around 450 nm). Moreover, the photoluminescence (PL) emission intensity and decay lifetime of Bi 3+ can be improved by substituting Mg 2+ for Li + . These changes should be attributed to the combined effects of the crystal field splitting and the superior lattice rigidity . Finally, the temperature-dependent PL spectra of the composition-optimized phosphor are measured, and the excellent thermal-stable emission (up to 473 K) has been obtained. It has been observed that Bi 3+ blue emission and Mn 4+ far-red emission exhibit different temperature quenching effect and such phosphor can be considered as an ideal candidate in optical thermometry.
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高影响因子
Small
·
2020
·Vol. 16
·期 25
·2001524
·
IF 11.459
Wei Zhang,Huangxu Li,Zhian Zhang,Ming Xu,Yanqing Lai,Shu-Lei Chou
Developing high-voltage cathode materials is critical for sodium-ion batteries to boost energy density. NASICON (Na super-ionic conductor)-structured Na x MnM(PO 4 ) 3 materials (M represents transition metal) have drawn increasing attention due to their features of robust crystal framework, low cost, as well as high voltage based on Mn 4+ /Mn 3+ and Mn 3+ /Mn 2+ redox couples. However, full activation of Mn 4+ /Mn 3+ redox couple within NASICON framework is still a great challenge. Herein, a novel NASICON-type Na 4 MnCr(PO 4 ) 3 material with highly reversible Mn 4+ /Mn 3+ redox reaction is discovered. It proceeds a two-step reaction with voltage platforms centered at 4.15 and 3.52 V versus Na + /Na, delivering a capacity of 108.4 mA h g −1 . The Na 4 MnCr(PO 4 ) 3 cathode also exhibits long durability over 500 cycles and impressive rate capability up to 10 C. The galvanostatic intermittent titration technique (GITT) test shows fast Na diffusivity which is further verified by density functional theory calculations. The high electrochemical activity derives from the 3D robust framework structure, fast kinetics, and pseudocapacitive contribution. The sodium storage mechanism of the Na 4 MnCr(PO 4 ) 3 cathode is deeply studied by ex situ X-ray diffraction (XRD) and ex situ X-ray photoelectron spectroscopy (XPS), revealing that both solid-solution and two-phase reactions are involved in the Na + ions extraction/insertion process.
研究领域:
材料科学
·
电化学
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高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Junze Tong,Long Li,Haiqing Su,Feng Hong,Edwin Yue Bun Pun,Hai Lin
Red-emitting Mn 4+ -doped fluoride phosphors are promising fluorescent material for use in high-performance warm white light emitting diodes (WLEDs). However, low stability and non-green synthesis method limit the development and commercialization of such phosphor. Herein, a series of novel (Li/Na/Cs) 0.4 Ba 0.8 SiF 6 :Mn 4+ phosphors with optimized fluorescence properties induced by alkaline metal ions replacement are successfully synthesized via a green and eco-friendly approach. Under the irradiation of 460 nm blue light, Cs 0.4 Ba 0.8 SiF 6 :Mn 4+ red phosphor with narrow band emission peak has the best optical performance. The optimal doping concentration of Mn 4+ in Cs 0.4 Ba 0.8 SiF 6 host and the reason for concentration quenching are systematically analyzed. Furthermore, the moisture resistance and thermal stability of this phosphor are discussed. After being soaked in deionized water for 90 min, the PL intensity of Cs 0.4 Ba 0.8 SiF 6 :Mn 4+ phosphor can maintain at 40% of that in air, which is 4 times higher than commercial K 2 SiF 6 :Mn 4+ . At the operating temperature of LED (423 K), Cs 0.4 Ba 0.8 SiF 6 :Mn 4+ red phosphor can exhibit stable light output intensity and color. A warm WLED with low correlated color temperature of 4336 K, high color rendering index of 88.4 and high lumen efficiency of 105.96 lm/W is fabricated via using Cs 0.4 Ba 0.8 SiF 6 :Mn 4+ phosphor as a component of red-light, and the warm WLED can maintain stable output even at high driving currents. Overall, the alkali metal ion replacement and green synthesis strategies have opened up a new perspective for the synthesis of efficient Mn 4+ -doped fluoride phosphors, which has dual benefits for optimizing the performance of WLED and environmental protection.
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高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 5
·1321-1329
·
IF 6.641
Daqin Chen,Yue Liu,Jiangkun Chen,Hai Huang,Jiasong Zhong,Yiwen Zhu
Efficient dual-modal luminescence is highly desired for applications in high security anti-counterfeiting. In the present work, Yb3+/Ln3+/Mn4+ (Ln = Er, Ho, and Tm) tri-doped Na3ZrF7 phosphors were fabricated via oil–water interface cation exchange using Yb3+/Ln3+:Na3ZrF7 as the exchanging hosts. The as-prepared products exhibited typical Mn4+ red down-shifting luminescence under UV light excitation and Er3+ red, Ho3+ yellow and Tm3+ near-infrared multi-color upconversion emissions under 980 nm laser excitation. The Mn4+ dopants in the Na3ZrF7 host experienced strong crystal-field strength Dq of 3.63 and showed superior thermal stability with up to 90% of the initial emission intensity retained at 448 K. Steady-state and time-resolved emission spectra verified that there was no detrimental energy transfer interaction between Mn4+ and Ln3+, enabling bright and eye-visible bi-functional emissions for the present products. As a consequence, the as-prepared phosphors were demonstrated to be applicable in anti-counterfeiting by a proof of concept experiment of fluorescent labeling for specially designed patterns.
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高影响因子
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