Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 43
·13536-13547
·
IF 6.641
Dongjie Liu,Peipei Dang,Xiaohan Yun,Guogang Li,Hongzhou Lian,Jun Lin
Recently, controllable luminescence tuning and single-phased white light emission have been extensively studied to improve the luminescence performances of phosphors for white light-emitting diodes (WLEDs). In this work, the controllable photoluminescence tuning from bluish-green to red was successfully achieved in Bi3+,Eu3+-codoped Sr2−yBayLaGaO5 solid solutions, combining the effects of crystallographic site engineering and energy transfer. The phase composition and structural variation of the designed phosphors were thoroughly analyzed through X-ray powder diffraction (XRD) and Rietveld refinement. The effects of cation substitutions on the photoluminescence properties were investigated in detail and the corresponding mechanism was proposed. A regular red-shift of Sr2−yBayLaGaO5:0.02Bi3+ in the bluish-green region could be observed when Sr2+ was substituted by Ba2+, which is attributed to the crystal field splitting and nephelauxetic effect. The red-shift of emission of Ba2LaGaO5:0.02Bi3+ phosphor with gradually increasing excitation wavelength reveals that Bi3+ ions occupy different cation sites to form multiple luminescent centers. Besides, the efficient energy transfer was designed and successfully realized in Sr2−yBayLaGaO5:0.02Bi3+,zEu3+ (y = 0–2.0; z = 0–0.20) samples. The energy transfer efficiency can reach up to 88%, 91% and 77% at z = 0.20 for y = 0, 1.0 and 2.0, respectively. Moreover, the thermal quenching behaviors of the studied phosphors reveal that the codoping of Eu3+ could efficiently improve the thermal stability of Sr2LaGaO5:0.02Bi3+ phosphor. Finally, the WLED devices were fabricated by composing 370 nm UV chips and single-phased Sr2−yBayLaGaO5:0.02Bi3+,0.05Eu3+ (y = 0, 1.0, 2.0) phosphors. The as-fabricated devices presented relatively excellent EL performances, the color coordinates of which all locate in the warm white light region. These results indicate the as-prepared Sr2−yBayLaGaO5:Bi3+,Eu3+ phosphors can be potential candidates for color tuning and efficient single-phased white emission in UV-based WLED lighting applications.
研究领域:
材料科学
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光学材料
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固态照明
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荧光粉化学
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能量传递
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高影响因子
TALANTA
·
2023
·
IF 6.1
Xiao Tian,Lei Zhao
Concentrations of trace elements in coal and coal combustion products are commonly analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) due to large number of elements detected and the relatively the low detection limits of this technique. Like other geological samples, complete dissolution of coal and coal combustion products is also essential for accurate ICP-MS results. In this study, Sr and Ba in coal and coal combustion products (fly and bottom ashes) from two coal-combustion power plants from North China analyzed by XRF and ICP-MS were comparatively studied. The concentrations of Sr and Ba analyzed by ICP-MS, when a mixture of acids (2 ml HF + 5 ml HNO 3 for each 50 mg coal sample and 5 ml HF + 2 ml HNO 3 for each 50 mg ash sample) was used for microwave-assisted digestion, do not fit well with the their relative XRF results. This is most probably due to the formation of the fluorides during microwave digestion, and this assumption is supported by the presence of various fluoride compounds, NaMgAl(F, OH) 6 ·H 2 O, NH 4 MgAlF 6 , AlF 3 , and K 2 SiF 6 , in the residues of all the coal and ash samples in our sequential extraction experiment. Cations of Sr and Ba were probably trapped into the divalent cation sites of the fluorides. Concentrations of Sr and Ba analyzed by ICP-MS using increased HF and HF/HNO 3 ratio (7 ml HF and 2 ml HNO 3 for each 50 mg coal/ash sample) are in better agreement with the XRF results. Our results indicate that excess amount of HF probably has led to the suppression of these elements due to fluoride precipitation. The results indicate that the modified digestion method is capable of achieving complete digestion of coal samples and results in a reliable analysis of Sr and Ba concentrations in coal samples and most fly ashes by ICP-MS. However, the formation of insoluble fluorides is probably not completely suppressed for some bottom ash samples, which can result in underestimation of Sr and Ba concentrations. Nevertheless, XRF analysis can serve as a reliable cross-check method to assist in the evaluation of the accuracy of ICP-MS results.
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高影响因子
CRYSTENGCOMM
·
2022
·Vol. 24
·期 37
·6492-6497
·
IF 3.756
Xinmei Wang,Lu Qi,Lei Wu,Ruixin Zhang,Maierhaba Abudoureheman,Jiarong Lv,Peng Wang,Xiaoyu Dong,Qun Jing,Zhaohui Chen
Three non-centrosymmetric (NCS) alkaline earth vanadyl(IV) phosphate hydrates, M(VO)2(PO4)2·4H2O (M = Ca, Sr, Ba) 1–3, have been successfully synthesized by a mild hydrothermal technique. The birefringence of 1–3 was calculated to be 0.093@1064 nm, 0.070@1064 nm and 0.133@1064 nm by first principles calculations, respectively. The large birefringence mainly comes from the perfect parallel arrangement of 2[V2P2O14]∞ layers and the force of hydrogen bonds, which is conducive for the enhancement of polarization anisotropy. Furthermore, we also studied other optical and thermal properties for the title compounds as well as the relationship between structures and properties. The results provide a new perspective for exploring nonlinear optical (NLO) materials with large birefringence in vanadyl phosphate hydrates.
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Polymer-Plastics Technology and Materials
·
2020
·
IF 0
Abdeldjalil Zegaoui,Mehdi Derradji,Aboubakr Medjahed,Hamid Abdelhafid Ghouti,Wan-An Cai,Wen-Bin Liu,Abdul Qadeer Dayo,Jun Wang,Yu-Guang Liu
As the huge demands for advanced engineering materials with specific properties, this study aimed to fabricate novel lightweight materials possessing ameliorated characteristics. The novel hybrid composites were prepared by reinforcing both the bisphenol-A based dicyanate ester and benzoxazine (DCBA/BA-a) resin blends using silane-treated short glass/basalt hybrid fibers through a compression molding technique, and then experimentally characterised. Results from the mechanical and thermal analyses revealed that the mechanical and thermal parameters were highly improved upon increasing the reinforcing phases’ amount. The shielding evaluations disclosed that the integration of hybrid fibers helped the DCBA/BA-a blend to possess excellent nuclear shielding properties.
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DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 34
·11999-12005
·
IF 4.39
Huanhuan Cheng,Abudukadi Tudi,Peng Wang,Kewang Zhang,Zhihua Yang,Shilie Pan
A new ternary Ba-based selenide, Ba3SiSe5, was synthesized by a high-temperature solid-state method. It crystallizes in the centrosymmetric space group Pnma (no. 62) of the orthorhombic system. The structure of the title compound consists of unique Se(4)Ba layers and discrete SiSe4 tetrahedra. The structure and computational properties of Ba3SiSe5 are systematically studied together with those of the Ba–MIV–Q (MIV = Si, Ge; Q = S, Se) system, and show an interesting difference in dimensions formed by one of the crystallographic Ba atoms and MIVQ4 tetrahedra, as well as optical property transformations modulated by MIV atoms. First principles methods were employed to obtain a better understanding of the relationship between structures and properties. Ba3SiSe5 maintains a moderate birefringence of 0.044@1064 nm and the real space atom cutting method indicates that the SiSe4 tetrahedra make the major contribution to its birefringence.
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PubMed
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 39
·395703
·
IF 3.874
Zhihua Li,Xin Ding,Bing Yu,Yu Min,Bin He,Youqing Shen,Hailin Cong
Near-infrared (NIR) emission materials can be widely applied in various fields, such as food detection, imaging, treatment, electronic products. With the trend of miniaturization of equipment, smaller materials are needed. In this work, we successfully synthesized a series of M2Ga2GeO7:N3+ (M = Ca, Ba, Sr; N = Cr, Nd, Er) samples and then focused on the study of Nd3+ doped Sr2Ga2GeO7 (SGGO). A series of SGGO:xNd3+ sub-micron phosphors were prepared via a microwave-assisted sol–gel process combined with subsequent calcination at 750 ℃, and the structural information and luminescent properties were systematically studied. SGGO is a representative tetragonal crystal and belonging to the space group of P4¯21m (113). The Nd3+ ions occupy eight-coordinated Sr2+ sites in the crystal lattice. From SEM analysis, the average particle size distribution is 219.7 ± 41.4 nm. The sub-micron phosphors have rich excitation spectra ranging from 350 nm to 850 nm and can produce multiband NIR emissions of 1331, 1056, and 905 nm when excited by ultraviolet and NIR light. The maximum emission intensity was obtained by optimizing the doping ratio of Nd3+ ions. A commercial chip was then utilized to fabricate light-emitting diodes (LEDs) to verify its application potential in NIR-II mini-LEDs. Compared with blue light LEDs, the as-prepared LEDs had good imaging penetration depth and could be clearly observed under 10 mm of chicken breast coverage. The maximum imaging penetration depth can be 33 mm.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 18
·1-16
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IF 2.8
Yang Zaizhi,Shen Yalong,Zhu Yuan,Jiang Xiaoming,Liu Rui,Yang Zhen,Wang Shouliang,Xu Dong
Flash sintering has revolutionized the field of advanced ceramic preparation with the low heating temperature and extremely short sintering time. The difference of doped ions radius can influence the defect structure and resistivity of the sample through lattice distortion, subsequently altering the parameters and dielectric properties of flash sintering samples. By flash sintering technology, co-doped TiO 2 ceramics with the acceptor ions (Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ ) and donor ions (Nb 5+ ) were successfully prepared at 1100 °C for 24 min. According to the blackbody radiation model, Mg 2+ and Nb 5+ co-doped TiO 2 ceramics exhibit the highest surface temperature at the moment of flash sintering, approximately 1852 °C. Additionally, the co-doped TiO 2 ceramics with Ba 2+ and Nb 5+ ions exhibit the strongest polarization effect, with a dielectric constant above 10 5 . The acceptor ions with larger ions increase oxygen vacancies by enhancing the stability of defect complexes. The excellent giant dielectric properties are attributed to the combined action of the electron-pinned defect dipole effect and the internal barrier layer capacitor effect.
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Materials Today
·
2025
·
IF 22
Haiping Luo,Shenglan Zhou,Wenjie Deng,Jiahao Liu,Jiaqing Peng,Bo Li,Zhihua Xiong,Wei Wang,Xinyu Ye
Fe 3+ is a promising near-infrared (NIR) activator ion due to its tunable emission and non-toxicity, which has attracted growing interest. However, developing high-performance broadband NIR-emitting phosphors based on Fe 3+ remains a significant challenge. In this work, we present Fe 3+ -activated A 2 LuSbO 6 (A = Ba/Sr/Ca) double perovskite phosphors, which exhibit unusually long-wavelength NIR emission (>850 nm). By adopting a cation substitution strategy at the A-site, we designed the gradual replacement of large-radius ions with small-radius ions, achieving controllable tuning of emission from 847 nm to 937 nm. This substitution process simultaneously reduces structural symmetry and induces octahedral distortion, which breaks the spin-forbidden transition of Fe 3+ and enhances luminescence performance. However, the continuous emission redshift leads to a large Stokes shift, which suppresses Fe 3+ luminescence. The combined effect of these two factors results in optimal luminescence efficiency in Sr 2 LuSbO 6 :1.0 %Fe 3+ (SLSO) sample, with internal/external quantum efficiencies (IQE/EQE) of 94.8 %/54.5 %. To further enhance luminescence performance, we introduced the rare-earth Yb 3+ , establishing an efficient Fe 3+ →Yb 3+ energy transfer (ET) channel that reduces non-radiative transition losses. Compared with the Yb 3+ -free sample, the SLSO:1.0 %Fe 3+ , 3.0 %Yb 3+ sample exhibits a broadened FWHM from 115 nm to 180 nm, enhanced IQE and EQE of 98.1 % and 56.4 %, respectively, and 13 % improved thermal stability. Finally, a pc-LED device based on the SLSO:1.0 %Fe 3+ , 3.0 %Yb 3+ phosphor demonstrates potential for applications in NIR spectroscopy analysis, night vision, biomedical imaging, and other fields. This work lays a foundation for further research on strategies to regulation the optical properties of Fe 3+ -activated NIR phosphors.
研究领域:
材料科学
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光学工程
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生物医学成像
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分子探针
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转化医学
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2026
·
IF 9.2
Dong-Chu Lu,Juan Xie,Yuan Gao,Cheng-Xin Li,Shan-Lin Zhang
The TEC of BFZYZ is lower to 13.8 × 10 −6 1/K, matching well with the electrolyte. • Y and Zn co-doping enhances hydration ability and surface oxygen vacancies. • BFZYZ yields an R p of 0.26 Ω cm 2 at 600 °C, 50% lower than that of BFZ. • PCFC with BFZYZ electrode achieved peak power density of 0.8 W/cm 2 at 600 °C. • The cell with BFZYZ electrode operates stably for 500 h. Developing active and durable oxygen electrodes for both oxygen reduction and oxygen evolution reactions at low temperatures remains a major challenge for proton ceramic electrochemical cells (PCECs). Herein, a cobalt-free Y and Zn co-doped Ba(Fe,Zr)O 3−δ perovskite (BFZYZ) is developed as a PCEC oxygen electrode, integrating excellent electrochemical performance and durability. At 600 °C, Y and Zn co-doping reduces the polarization resistance by 50%, mainly owing to enhanced hydration capability and surface oxygen exchange, which accelerate ORR/OER kinetics. Meanwhile, BFZYZ shows a lower average thermal expansion coefficient of 13.8 × 10 −6 1/K over 30–600 °C, improving its thermal compatibility with the electrolyte. The PCEC with BFZYZ electrode achieves a peak power density of 0.8 W/cm 2 in fuel cell mode and a current density of 0.82 A/cm 2 at 1.3 V in steam electrolysis mode at 600 °C, with stable operation, demonstrating the potential of BFZYZ for high-performance and durable PCECs.
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高影响因子
Russian Journal of Physical Chemistry A
·
2022
·Vol. 96
·期 8
·1761-1767
·
IF 0.791
Chen Yu,Liu Miao
Abstract A modified polyacrylamide gel route with urea used as fuel was used to synthesize the MFe 2 O 4 (M = Mg, Ca, Ba) iron oxides with high adsorption capacity for removal of Cd(II) from water treatment. The phase structure, functional group, porous structure and adsorption performance of MFe 2 O 4 (M = Mg, Ca, Ba) iron oxides were characterized by X-ray-diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), N 2 adsorption–desorption isotherm and 721 spectrophotometer. The result indicates that the phase forming temperature of MFe 2 O 4 , the content of carbonate ion in MFe 2 O 4 increases with the increasing of the radius of M-site metal ion. The E g value, BET surface area and adsorption capacity for removal of Cd(II) from water treatment decreases with the increasing of the radius of M-site metal ion. The experimental isotherm of MFe 2 O 4 (M = Mg, Ca, Ba) iron oxides were described by the Langmuir model. MgFe 2 O 4 iron oxide exhibits a best adsorption performance for removal of Cd(II) from water treatment by the adsorption process, with a maximum adsorption capacity of ca. 221.36 mg/g than that of other iron oxides. The present synthetic route could be possibly extended to synthesize other porous metal oxide materials with special porous structures for various applications.
研究领域:
环境科学
·
材料科学
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高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 46
·12566-12574
·
IF 5.976
Xiaohui Li,Lei Zhou,Miroslav D. Dramićanin,Qiang Tang,Xiping Jing,Jianxin Shi,Yiqin Xu,Mingmei Wu
Broad emission with a full and continuous color spectrum realized by crystal engineering is extensively desired to simulate natural sunlight and improve the white color quality. Herein, new insight into the modulation of B site order–disorder and intrinsic oxygen defects for complex perovskite (A3B′B2′′O9) Sr3−xScxZnNb2O9 (0 ≤ x ≤ 0.1) phosphors is demonstrated for broad-band emission via crystal engineering. We elucidate that the spectrum of Sr3ZnNb2O9 synthesized at an optimal temperature exhibits two emission bands under near-ultraviolet excitation (λex = 374 nm) which is readily available from near ultraviolet chips. The two broad emission bands can be ascribed to charge transfer from the empty 4d (t2g)-orbitals of Nb5+ ions to the filled 2p-orbitals of O2− ions and the intrinsic oxygen defects. Further, as a proposed strategy to optimize the luminescence property of Sr3ZnNb2O9 (SZN), we realized A-site nonequivalent doping to induce B-site disordering and cancel the luminescence quenching which results from B site ordering. The A-site nonequivalent doping efficiently offsets intrinsic oxygen defects, as validated by systematic analyses of experiments and DFT calculations. Consequently, the novel phosphor Sr3−xScxZnNb2O9 (x = 0.1) shows a high color rendering index (Ra = 82.2) and negligible color shift. In addition, its emission intensity is enhanced by ∼70 times as compared to the pristine Sr3ZnNb2O9.
研究领域:
材料科学
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发光材料
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固态化学
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荧光粉
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光学材料
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DOI
高影响因子
Agronomy-Basel
·
2025
·Vol. 15
·期 9
·2211
·
IF 3.4
Zheng Zhang,Jingfang Wei,Leifeng Xu,Jun Ming,Panpan Yang
Lilium browniivar.viridulumis a popular natural health product that combines medicine and food. However, the lack of high-quality and efficient propagation technology has been a significant impediment to the development of theL. browniivar.viridulumindustry. In this study, bulb scales ofL. browniivar.viridulumwere used as materials to investigate the induction of bulblets from scales, as well as the proliferation and enlargement of the induced bulblets. An in vitro regeneration system forL. browniivar.viridulumwas successfully established. The most effective methods for scale disinfection were found to be 75% alcohol disinfection for 30 s and 10% Sodium Hypochlorite (NaClO) disinfection for 15 min. The recommended medium for scale differentiation was Murashige and Skoog (MS) + 0.05 mg·L−11-Naphthaleneacetic acid (NAA) + 0.25 mg·L−1Thidiazuron (TDZ) + 0.05 mg·L−1kinetin (KIN) + 30 g·L−1sucrose + 6 g·L−1Activated Charcoal (AC). The recommended medium for bulblet proliferation was MS + 1.5 mg·L−16-benzylaminopurine (6-BA) + 0.5 mg·L−1NAA + 30 g·L−1sucrose. The recommended medium for bulblet enlargement was Modified MS Medium (potassium dihydrogen phosphate (KH2PO4, KDP) doubled) + 90 g·L−1sucrose. Bulblets with diameters of 1.5 cm were transplanted, and the germination rate was 100%. This study established a systematic in vitro regeneration system forL. browniivar.viridulum, which will provide the foundation for industrial production ofL. browniivar.viridulumbulbs and improvement through genetic transformation.
研究领域:
植物学
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植物组织培养
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园艺学
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植物繁殖
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生物技术
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高影响因子
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