JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 28
·期 20
·15004-15008
·
IF 2.019
Cao Renping,Liu Xing,Bai Kailei,Chen Ting,Luo Zhiyang,Zheng Guotai,Ao Hui,Fu Jingwei
RMgPO 4 :Mn 2+ (R = Li, Na, and K) phosphors are synthesized by a solid-state reaction method in air. The crystal structures and luminescence properties are investigated. A broad emission band peaking at 638 nm of RMgPO 4 :Mn 2+ (R = Li and Na) phosphors with excitation 408 nm is observed in the range of 550–800 nm owing to the 4 T 1 (G) → 6 A 1 transition of the Mn 2+ ion. KMgPO 4 :Mn 2+ phosphor with excitation 416 nm shows a broad emission band peaking at 658 nm in the range of 550–800 nm owing to the 4 T 1 (G) → 6 A 1 transition of the Mn 2+ ion. The optimal Mn 2+ ion concentration in RMgPO 4 :Mn 2+ (R = Li, Na, and K) phosphors is about 5 mol%. The lifetimes of RMg 0.95 PO 4 :0.05Mn 2+ (R = Li, Na, and K) phosphors is ~6.21, 6.03, and 6.28 ms, respectively. The luminous mechanism is explained by Tanabe-Sugano diagram of Mn 2+ ion.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Feng Gao,Qing Pang,Dangli Gao,Chaoyang Jia,Hong Xin,Yong Pan,Yuhua Wang,Sining Yun
Photostimulable luminescence (PSL) nanophosphors, which exhibit superior features including controllable energy storage and efficient photon release upon light stimulation, are desirable for optical signal storage. However, trap tuning of the storage phosphor remains a great challenge. Herein, the PSL of Zn2GeO4:Mn2+ nanophosphors is enhanced via creating deep traps through nonequivalent Pr3+ doping. The possible enhanced mechanisms are analyzed combined with doping models using the first-principles theory. A mechanism is proposed based on changing the coordination environment of Mn2+, creating deep traps and tuning the band gap structure, and thus providing the chance for electrons’ photoionization and PSL generation. As a result, the prepared nanophosphors demonstrate the superior functionalities for optical signal storage. This work not only offers an insight into defect engineering through doping strategies for developing PSL materials but also supplies a good candidate for optical information storage.
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 EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Zixin Wang,Hui Lin,Dawei Zhang,Ruijin Hong,Yanna Tian,Jie Chen,Shengming Zhou
In this paper, Ba 0.75 Al 11 O 17.25 was selected as the host for the Eu 2+ and Mn 2+ co-dopants due to the Reidinger defects in its lattice. Upon the 365 nm excitation, the phosphors presented the cyan to green tunable emission by changing the doping concentration of Mn 2+ . Moreover, this phosphor possesses zero-thermal quenching up to 448 K due to the interaction between the traps and Eu 2+ /Mn 2+ . The completely densified ceramic guaranteed the high optical transmittance (∼72 % at 516 nm) and thermal conductivity (4.3 W·m −1 ·K −1 at room temperature). When combined with a 6 W commercial 365 nm emitting LED chip, the temperature of the ceramic eventually stabilized at 428 K and the luminous efficacy of the LED device was almost not influenced by the thermal quenching effect. This work may open a way for exploring new phosphor conversion materials for HP/HB PC solid state lighting.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 23
·22998-23008
·
IF 2.8
Zhao Junfeng,Wang Qun,Fu Yongsheng,Peng Bo,Zhou Gaofeng
In this study, the effect of Fe 3+ , Fe 2+ , and Mn 2+ dose, solution pH, reaction temperature, background water matrix (i.e., inorganic anions, cations, and natural organic matters (NOM)), and the kinetics and mechanism for the reaction system of Fe(VI)/Fe 3+ , Fe(VI)/Fe 2+ , and Fe(VI)/Mn 2+ were investigated systematically. Traces of Fe 3+ , Fe 2+ , and Mn 2+ promoted the DCF removal by Fe(VI) significantly. The pseudo-first-order rate constant ( k obs ) of DCF increased with decreasing pH (9–6) and increasing temperature (10–30 °C) due to the gradually reduced stability and enhanced reactivity of Fe(VI). Cu 2+ and Zn 2+ ions evidently improved the DCF removal, while CO 3 2− restrained it. Besides, SO 4 2− , Cl − , NO 3 − , Mg 2+ , and Ca 2+ almost had no influence on the degradation of DCF by Fe(VI)/Fe 3+ , Fe(VI)/Fe 2+ , and Fe(VI)/Mn 2+ within the tested concentration. The addition of 5 or 20 mg L −1 NOM decreased the removal efficiency of DCF. Moreover, Fe 2 O 3 and Fe(OH) 3 , the by-products of Fe(VI), slightly inhibited the DCF removal, while α-FeOOH, another by-product of Fe(VI), showed no influence at pH 7. In addition, MnO 2 and MnO 4 − , the by-products of Mn 2+ , enhanced the DCF degradation due to catalysis and superposition of oxidation capacity, respectively. This study indicates that Fe 3+ and Fe 2+ promoted the DCF removal mainly via the self-catalysis for Fe(VI), and meanwhile, the catalysis of Mn 2+ and the effect of its by-products (i.e., MnO 2 and MnO 4 − ) contributed synchronously for DCF degradation.
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研究领域:
环境科学
·
化学动力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2023
·
IF 5.4
Renping Cao,Yongtong Rong,Yewen Cao,Ban Lan,Chenxing Liao,Jingheng Nie,Fangrui Cheng,Jing Wang
Now free rare earth ions doped materials have attracted a lot of attention. In this work, CaNb 2 O 6 :Mn 2+ with a pure phase is synthesized by solid-state method in the reducing atmosphere. The crystal structure and luminescence properties of host (CaNb 2 O 6 ) and CaNb 2 O 6 :Mn 2+ are investigated. Host (CaNb 2 O 6 ) under excitation ultraviolet (UV) light emits blue light. CaNb 2 O 6 :Mn 2+ can show tunable emission from blue to white. Under excitation 260 nm, blue emission of CaNb 2 O 6 :Mn 2+ is observed owing to the 4 T 1 ( 4 G) → 6 A 1 ( 6 S) transition of Mn 2+ . When the excitation wavelength is 314 nm, CaNb 2 O 6 :Mn 2+ emits white light due to the 4 T 1 ( 4 G) → 6 A 1 ( 6 S) transition of Mn 2+ and the 6 A 1 (6S) 4 T 1 (4G) → 6 A 1 (6S) 6 A 1 (6S) transition in Mn 2+ - Mn 2+ dimers. We measure the concentration dependent spectra of CaNb 2 O 6 :Mn 2+ and make sure the optimal Mn 2+ doping concentration (∼0.8 mol%). We infer that the concentration quenching mechanism is the electric multipolar interaction between nearest-neighbor ions. Based on the temperature dependent spectra of CaNb 2 O 6 :Mn 2+ , we came to the conclusion that CaNb 2 O 6 :Mn 2+ has a good thermal stability. We analyze the concentration and thermal quenching mechanisms and explain the luminous mechanism by the Tanabe-Sugano energy level diagram of Mn 2+ ion. This research results provide a framework for creating Mn 2+ -doped luminescent materials .
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Materials Chemistry Frontiers
·
2020
·Vol. 5
·期 2
·937-943
·
IF 6.788
Xupeng Gao,Xinyu Shen,Dingke Xue,Xin Li,Po Lu,Min Lu,Chunyan Li,William W. Yu,Xue Bai
Two-dimensional (2D) perovskites have become a research hotspot due to their large exciton binding energy and excellent stability. However, it is difficult to achieve longer wavelength emission than blue and green light in the 2D perovskites owing to their wide band gap resulting from their strong quantum confinement. Herein, we demonstrate a simple, efficient and low energy consumption crystallization method at room temperature to synthesize Mn2+ ion doped 2D (PEA)2PbBr4 nanocrystals (NCs) with dual-color emission centered at 410 nm from the exciton transition of the host and 600 nm from the d–d transition of Mn2+ ions. The periodic XRD peaks prove the formation of 2D perovskites. It is reassuring that the high PLQY of 54% has been achieved in the Mn2+ ion doped 2D (PEA)2PbBr4 NCs. The temperature-dependent and time-resolved spectra illustrate the efficient energy transfer from excitons to Mn2+ dopant ions. The realization of white LEDs with different color temperatures presents an opportunity and prospect for Mn2+ ion doped 2D perovskites in LED application.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
SOLID STATE SCIENCES
·
2018
·
IF 1.861
Jie Lu,Linjiang Shen
Recently, developing free rare-earth (RE) doped afterglow phosphors has received great attentions in the lighting field. In this work, we prepare and report a RE-free phosphor, Na 2 BeGeO 4 :Mn 2+ , which can simultaneously emit the green fluorescence and afterglow luminescence upon excitation at UV light. Our results reveal that the as-prepared samples crystallize in orthorhombic type with the space group of Pmn 2 1 (31). The green emission is a broad band centered at 525 nm, corresponds to the 4 T 1 ( 4 G)- 6 A 1 ( 6 S) transition of Mn 2+ ions. After exposing to a 254 nm UV lamp for 10 min, the green afterglow luminescence seen with naked eyes can last more than 5 h. Together with the structural analysis and thermoluminescence (TL) spectra, the afterglow luminescence mechanism is also discussed in this work.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Wei Wang,Hang Yang,Meiqian Fu,Xinyang Zhang,Mengyu Guan,Yi Wei,Chun Che Lin,Guogang Li
Thermal quenching is still a pivotal challenge for phosphor materials in white light emitting diodes lighting applications. Herein, we propose an effective strategy to design a near zero-thermal-quenching green emission in zero-thermal-expanding Zn 4 B 6 O 13 host based on unique 3D isotropic cage structure. The integrated emission intensity of Zn 4 B 6 O 13 :Mn 2+ could maintain 103% of initial intensity at 150 °C and 98% at 250 °C under blue light excitation. During the low-frequency vibrations, the unchanged bonds and angles induce the zero thermal expansion, and the unaffected lattice and coordination environment contribute the nearly unchanged emission intensity during the heating process. In addition, an efficient self-reduction of activators in the studied system is ascribed to vacancy and interstitial oxygen defects act as donors to provide electrons. This work initiates a novel strategy to construct thermally-stable and self-reductive phosphors for multiple optical applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Biotechnology for Biofuels
·
2018
·Vol. 11
·期 1
·1-19
·
IF 5.497
Chen Yumeng,Shen Yaling,Wang Wei,Wei Dongzhi
Background The filamentous fungus Trichoderma reesei Rut-C30 is one of the most vital fungi for the production of cellulases, which can be used for biofuel production from lignocellulose. Nevertheless, the mechanism of transmission of external stimuli and signals in modulating cellulase production in T. reesei Rut-C30 remains unclear. Calcium is a known second messenger regulating cellulase gene expression in T. reesei.Results In this study, we found that a biologically relevant extracellular Mn2+ concentration markedly stimulates cellulase production, total protein secretion, and the intracellular Mn2+ concentration of Rut-C30, a cellulase hyper-producing strain of T. reesei. Furthermore, we identified two Mn2+ transport proteins, designated as TPHO84-1 and TPHO84-2, indicating that they are upstream in the signaling pathway that leads to cellulase upregulation. We also found that Mn2+ induced a significant increase in cytosolic Ca2+ concentration, and that this increased cytosolic Ca2+ might be a key step in the Mn2+-mediated regulation of cellulase gene transcription and production. The utilization of LaCl3 to block plasma membrane Ca2+ channels, and deletion of crz1 (calcineurin-responsive zinc finger transcription factor 1) to interrupt calcium signaling, showed that Mn2+ exerts the induction of cellulase genes via calcium channels and calcium signaling. To substantiate this, we identified a Ca2+/Mn2+ P-type ATPase, TPMR1, which could play a pivotal role in Ca2+/Mn2+ homeostasis and Mn2+ induction of cellulase genes in T. reesei Rut-C30.Conclusion sTaken together, our results revealed for the first time that Mn2+ stimulates cellulase production, and demonstrates that Mn2+ upregulates cellulase genes via calcium channels and calcium signaling. Our research also provides a direction to facilitate enhanced cellulase production by T. reesei.
研究领域:
微生物学
·
分子生物学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Liang Shi,Xueying Wang,Rui Peng,Yongcheng Lu,Cheng Liu,Dainan Zhang,Huaiwu Zhang
A series of Mn 2+ -doped Mg 1-x Mn x Ta 2 O 6 (x = 0.02, 0.04, 0.06, 0.08, 0.10, 0.12) ceramics were synthesized by solid-state reaction method. The influence of introducing Mn–O bonds as a partial replacement for Mg–O bonds on the lattice and microwave dielectric properties was systematically investigated. XRD and Rietveld refinement confirm that Mn 2+ occupies the 2a Wyckoff position and forms a pure trirutile phase. Moreover, based on the chemical bond theory, the dielectric constant is mainly affected by the ionicity of the Ta–O bond. The lattice and dielectric properties remain relatively stable with Mn 2+ doping below 0.1, but excessive Mn 2+ doping leads to pronounced distortion of the lattice, which is not beneficial for lattice stability and microwave dielectric properties. Introducing an appropriate amount of Mn–O bonds with high bond dissociation energy facilitates MgO6 octahedron stability, which improves the thermal stability of the lattice. Accordingly, the microwave dielectric properties for 0.06 Mn 2+ -doped MgTa 2 O 6 ceramics were determined: ε r = 28, Q × f = 105,000 GHz (at 7.5 GHz), τ f = 19.5 ppm/ ° C.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2015
·Vol. 44
·期 39
·17286-17292
·
IF 4.197
Xia Xu,Zhuo Wang,Pengpeng Lei,Xiuling Liu,Yue Su,Lile Dong,Shuang Yao,Liang Zhou,Shuyan Song,Jing Feng,Hongjie Zhang
Cubic KLu3F10 nanocrystals have been fabricated by doping Mn2+ ions via a liquid–solid solution (LSS) hydrothermal method. With an increase in the Mn2+ level, a phase transformation from orthorhombic KLu2F7 to cubic KLu3F10 associated with evolution of the particle morphologies and sizes is evident. The phase transformation mechanism based on doping with Mn2+ ions was studied via a series of time-controlled experiments and the enhancement of the intensity of upconversion luminescence (UCL) via doping with Mn2+ ions is discussed in detail. In addition, under 980 nm excitation, the UCL properties of Er3+/Tm3+/Ho3+-doped KLu3F10:Yb3+ upconversion nanoparticles (UCNPs) have been investigated and a possible UCL mechanism has been discussed. It has been demonstrated that cubic KLu3F10 is an excellent host for upconversion luminescence.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Ce Qiu,Xiaohui Zhu,Liang Xue,Mingzhu Ni,Yang Zhao,Bo Liu,Hui Xia
Adding Mn 2+ in aqueous electrolyte is a well adopted approach to improve cycle performance for Zn/MnO 2 batteries. The function of Mn 2+ additive in aqueous electrolyte, however, is not well understood, which could affect revealing the real performance of the MnO 2 cathode itself. In this work, a battery system with Zn anode and birnessite MnO 2 cathode is constructed and systematically investigated by using MnSO 4 additive in the electrolyte with different concentrations. The function of Mn 2+ in the electrolyte, the structural evolution of the electrode, the reaction mechanism, and the cause for capacity fading are comprehensively investigated in this system. It is found that Mn 2+ can be continuously electro-oxidized at the cathode and form ε-MnO 2 when the charge voltage is above 1.7 V during cycling, leading to successive capacity increase up to hundreds of cycles. The capacity increase, however, stops after certain cycle numbers, and is followed by fast capacity fading, which is correlated to the competition between ε-MnO 2 formation and phase transition from birnessite to spinel ZnMn 2 O 4 . It is suggested that addition of Mn 2+ in the electrolyte cannot stabilize the MnO 2 cathode and the improved cycle performance is achieved at the expense of consuming the Mn 2+ in the electrolyte.
研究领域:
电化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）