JOURNAL OF RARE EARTHS
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2023
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IF 4.9
Jixiang Yue,Lichun Cheng,Jilei Xiong,Qingrong Yao,Man Wang,Yucheng Chen,Qianxin Long,Xiaojian Guo
A simple composite Sr 1– x Nd x MnO 3 ( x = 0, 0.05, 0.1, 0.15, 0.2) nano powders were successfully prepared by the sol–gel method as a light-weight broadband electromagnetic wave absorber. The effect of Nd 3+ doping on the structure, microstructure and properties of SrMnO 3 was investigated. It is found that with the doping of Nd 3+ , the space group of the SrMnO 3 changes from p 63/ mmc to pm 3 m , and the crystalline shape starts to change from hexagonal to cubic crystalline. Scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) tests confirm that the particle sizes of the sample decrease and the specific surface area increases, which are attributed to the inhibition of grain growth after Nd 3+ is doped. X-ray photoelectron spectroscopy (XPS) shows that after Nd 3+ doping, the content of oxygen vacancy increases, and Mn 4+ converts to Mn 3+ . Due to the defects of the materials, the polarization effect is enhanced, thus, the dielectric and magnetic properties of the doped samples are improved. The maximum reflection loss of the Sr 0.85 Nd 0.15 MnO 3 is −33.41 dB at 7.84 GHz for a thickness of 2.4 mm, while Sr 0.9 Nd 0.1 MnO 3 has the best bandwidth performance at 2.32 GHz with a reflection loss below −10 dB.
研究领域:
材料科学
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物理学
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高影响因子
Sustainable Energy & Fuels
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2023
·Vol. 7
·期 4
·1027-1040
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IF 5.6
Ke Gao,Xianglei Liu,Qi Wang,Zhixing Jiang,Cheng Tian,Nan Sun,Yimin Xuan
Solar thermochemical CO2 splitting has emerged as a promising strategy for solar fuel production to alleviate climate change challenges and reduce the energy crisis. However, traditional redox materials still suffer from low CO production, poor cycle stability, high operating temperature, and large temperature swing, leading to low solar-to-fuel efficiency. Herein, Ce- and Al-doped SrMnO3 perovskites are proposed for high-performance solar thermochemical CO2 splitting within moderate temperature swing (1350/1100 °C). Sr0.6Ce0.4Mn0.8Al0.2O3 demonstrates a remarkable CO yield of 799.34 μmol g−1, which is ∼6.67 times as high as that of benchmark CeO2. Fast CO2 splitting kinetics of SCMA20 is demonstrated by the CO peak production rate enhanced by 142% compared with undoped SrMnO3. The proposed Sr0.6Ce0.4Mn0.8Al0.2O3 also exhibits excellent stability with no obvious deactivation or degradation over multiple cycles. The ultrahigh CO yield can be attributed to lower oxygen vacancy formation (3.65 eV) and migration energy (2.14 eV) as confirmed by DFT calculations, and the transformation of the first-order reaction (F1) to the second-order reaction (F2) compared to SrMnO3. This work provides a new path for high-performance solar thermochemical CO2 splitting with high CO production, fast reaction kinetics, good cycling stability, moderate temperature swing, and high solar absorptance.
研究领域:
材料科学
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能源化学
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环境科学
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2018
·Vol. 29
·期 11
·9613-9620
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IF 2.324
Zhang Jun,Kong Wenwen,Chang Aimin
The [Mn 1.56 Co 0.96 Ni 0.48 O 4 ] 1−x [SrMnO 3 ] x ((MCN) 1−x (SM) x , 0 ≤ x ≤ 0.5) ceramic thin composite films were grown on SiO 2 /Si (100) substrates by the chemical solution deposition (CSD) method. The results of X-ray diffraction showed that the (MCN) 1−x (SM) x (0 < x ≤ 0.5) films were a resemblance of the spinel–perovskite composite structure. The field emission scanning electron microscope analyses presented a considerable improvement in relative density with the increasing of the SM contents. In particular, the thermal constant of (MCN) 1−x (SM) x ceramic film increased from 3289 to 5390 K with the increasing of the SM contents (x) from 0 to 0.5. This feature was attributed to the increase in the grain boundary resistance and the increase in Mn 3+ /Mn 4+ pairs as the SM contents increased. From the spectroscopic ellipsometer spectroscopy results, it was found that the (MCN) 0.5 (SM) 0.5 film had the biggest refractive index n value of 2.36 at 1.5 eV and a strong absorption peak at 4.0 eV. The sensitivity of MCN spinel ceramic film was enhanced by the compounding of SM. It was a significant disposition in the study of negative temperature coefficient thermistors.
研究领域:
材料科学
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电子工程
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物理学
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高影响因子
Greenhouse Gases-Science and Technology
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2023
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IF 2.2
Zifan Xing,Haitao Chen,Min Mao,Xiaocen Liang,Da Song,Yang Li,Tao Long,Xiaoli Chen,Fang He
The chemical looping oxidative dehydrogenation (CL-ODH) of ethane represents a highly effective approach for converting ethane into the value-added product ethylene. This investigation focused on the synthesis of SrMnO 3 and its halide ions doped derivatives (SrMnO 3 Cl and SrMnO 3 Br) through the sol-gel method. The performance of these perovskites, employed as oxygen carriers in CL-ODH of ethane, was explored. The results unveiled several advantageous outcomes arising from the incorporation of halide ions (Cl − and Br − ) with larger radius into the oxygen sites of the SrMnO 3 perovskite. Halide ions doping notably induced cell volume expansion and enhanced lattice fringe spacing. Furthermore, it contributed to elevated oxygen vacancy concentration, increased Mn 4+ /Mn 3+ molar ratio, and improved oxygen ions mobility within the bulk lattice. Fixed-bed experiments demonstrated that these redox catalysts, doped with halide ions, exhibited outstanding activity and stability during cycling tests, exhibiting enhanced both ethylene selectivity and yield in CL-ODH of ethane. In summary, the introduction of halide ions into SrMnO 3 emerges as a promising strategy for enhancing the performance of CL-ODH in ethane conversion for SrMnO 3 based oxygen carriers. © 2023 Society of Chemical Industry and John Wiley & Sons, Ltd.
研究领域:
化学工程
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催化
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材料科学
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高影响因子
CERAMICS INTERNATIONAL
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2025
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IF 5.6
Changle Mei,Jixiang Yue,Fenxing Ye,Changming Wang,Yanglin Luo,Qingrong Yao,Jianqiu Deng,Lichun Cheng
Ion doping can significantly enhance microwave absorption performance. In this paper, powders of Sr 1- x Gd x MnO 3 ( x = 0, 0.02, 0.04, 0.06) were synthesized via a simple sol-gel process. Comprehensive characterization elucidated the phase evolution, microstructure, valence states, magnetic properties, and electromagnetic attenuation mechanisms of Gd-doped SrMnO 3 . With the incorporation of Gd 3+ , the crystal structure of Sr 1- x Gd x MnO 3 transitions from hexagonal to cubic. The crystal lattice develops substantial defects, while the resulting valence imbalance drives the reduction of Mn 4+ to Mn 3+ . These synergistic effects enhance multipolarization phenomena, including defect polarization and charge polarization. Notably, the addition of an appropriate amount of Gd ions to the material can effectively adjust its electromagnetic parameters and optimizes impedance matching. Among the synthesized samples, Sr 0.94 Gd 0.06 MnO 3 exhibits optimal microwave absorption performance, achieving a minimum reflection loss of −36.6 dB at 9.84 GHz and an effective absorption bandwidth of 3.04 GHz at a thickness of 2.2 mm. Additionally, an effective absorption bandwidth of 4.0 GHz is achieved for x = 0.02 at a thickness of 1.6 mm. These results not only indicate that Gd 3+ doping significantly enhances the absorbing properties of SrMnO 3 but also provide valuable theoretical guidance for the design of high-efficiency electromagnetic wave absorption materials in future research.
研究领域:
材料科学
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电磁学
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固体物理
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无机化学
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高影响因子
Aerosol and Air Quality Research
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2025
·Vol. 25
·期 7
·1-10
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IF 2.5
Yu Peng,Shi Jing,Wan Hangjiang,Tang Zijian,Yuan Kangyu,Li Xi,Sun Yongjun,Zhang Xiao,Xu Yanhua
Background SrMnO 3 demonstrates high efficiency in degrading chlorinated volatile organic compounds (CVOCs). However, the accumulation of chlorine species and the loss of active sites limit the further enhancement of its catalytic performance. Purpose To improve the catalytic and chlorine poisoning resistance properties of SrMnO 3 -based catalyst. Methods A modified hydrothermal method was employed to synthesize a multi-metal-oxides catalyst based on SrMnO 3 with Ce introduced to lattice to increase surface defect density. Influences of catalyst dosage, relative humidity, pollutant concentration and airspeed on chlorobenzene (CB) removal efficiency were systematically investigated. Results The results revealed the great removal efficiency of the multi-metal-oxides catalyst based on SrMnO 3 with T 90 of 247 ℃, T 95 of 269 ℃, and the mineralization rate of 71%. The catalytic mechanism on the catalyst was explored through comprehensive characterizations and the potential degradation pathways of CB were inferred. Conclusion This work provides new insights into the design of metal-doped perovskite catalysts, highlighting the critical role of surface defects and oxygen vacancies in catalytic performance. Graphical
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