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Core-shell structured MoS_2@S spherical cathode with improved electrochemical performance for lithium-sulfur batteries

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Journal of Materials Science & Technology 2018年第10期34卷 1912-1918页

作者： Songpu Cheng Xiaohong Xia Hongbo Liu Yuxi Chen College of Materials Science and Engineering Hunan University

To suppress shuttling effect and improve electrochemical performance of the sulfur cathode for lithium- sulfur batteries, core-shell structured MoS2 @S spherical cathode has been synthesized through a chemical route using MnC03 as template. The MoS2 shells consist of MoS2 nanosheets. For comparison, MoS2/S cathode has also been synthesized through melting and diffusion of sulfur to commercial MoS2 pow-ders. The electrochemical performance of the MoS2@S and MoS2/S cathodes have been evaluated using cyclic voltammetry, discharge/charge cycling, electrochemical impedance spectroscopy coupled with impedance fitting. The electrochemical performance of the MoS2@S spherical cathode has been much improved compared with that of MoS2/5. The capacity of the MoS2 @S spheres can reach 1185.7 mA h g^-1 at 0.2 C and 955.1 mA h g^-1 at 1 C with initial-cycle coulombic efficiency of 90%. The capacity fading of each cycle is 0.1% during 200 lithiation/delithiation cycles. The MoS2 @S spherical cathode with high cyclic capacity and stability is promising cathode candidate for lithium-sulfur batteries.

关键词： Core-shell particle Electrochemical property Electrode MoS2 sulfur

Copper-catalyzed three-component reaction of imidazo[1,2-a]pyridine with elemental sulfur and arylboronic acid to produce sulfenylimidazo[1,2-a]pyridines

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Chinese Chemical Letters 2018年第9期29卷 1363-1366页

作者： Genhua Xiao Hao Min Zhilei Zheng Guobo Deng Yun Liang National & Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research Ministry of Education Key Laboratory of the Assembly and Application of Organic Functional Molecules College of Chemistry and Chemical Engineering Hunan Normal University

In this work, an efficient copper-catalyzed three-component reaction for the synthesis of sulfenylimidazo [1,2-a]pyridines using elemental sulfur as the sulfenylating agents has been developed. The reaction could proceed smoothly with a high degree of functional group tolerance and provide the desired products in moderate to good yield.

关键词： Copper Three-component Pyridine sulfur Arylboronic acids

Reduction of SO2 to elemental sulfur over rare earth-iron catalysts

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Journal of Rare Earths 2009年第5期27卷 744-748页

作者： DENG Gengfeng JIANG Kun CAO Xia LIAO Chunfa School of Materials and Chemical Engineering Jiangxi University of Science and Technology Ganzhou 341000 China School of Materials and Chemical Engineering Jiangxi University of Science and Technology Ganzhou 341000 China Nanchang Engineering and Research Institute of Nonferrous Metals Nanchang 330000 China School of Materials and Chemical Engineering Jiangxi University of Science and Technology Ganzhou 341000 China

With coal gas as a reducing agent, the catalytic reduction of SO2 to sulfur in the flue gas produced in metallurgical processes was studied over catalysts of rare earth-Fe/Al2O3 (REFe/Al2O3). The catalytic activity of the REFe/Al2O3 catalyst on the reduction of SO2 to sul-fur was investigated based on kinds and the contents of rare earths and different preparation method of the catalyst. Additionally, the mecha-nism of this catalytic reduction reaction was also explored. Results showed that different rare earth imposed different effect on the activity of the Fe/Al2O3 catalyst. Especially, the addition of Sm and Dy greatly improved the catalytic activity of Fe/Al2O3. The yield of sulfur over SmFe/Al2O3was increased to 86.62% at 360 ℃, which was 40.5% higher than that over Fe/Al2O3at the same temperature; and the sulfur yield over DyFe/Al2O3was increased to 91.62% at 400 ℃, 26.4% higher than that over Fe/Al2O3. The catalytic activity of REFe/Al2O3 was somehow dependent on the content of rare earth. For SmFe/Al2O3, the content of Sm was optimized to be about 1.0 wt.%. The rare earth catalyst prepared with different methods also showed varied activity. The sulfur yield over rare-earth transition metal catalysts follows the order: Sm and iron solution mixing impregnationSm first, then iron solution impregnationiron first, then Sm solution impregnation. The reaction mechanism of SO2 reduction to sulfur with coal gas was proposed to be an intermediate mechanism.

关键词： sulfur dioxide catalytic reduction sulfur flue gas rare earths

One-pot synthesis of highly conductive nickel-rich phosphide/CNTs hybrid as a polar sulfur host for high-rate and long-cycle Li-S battery

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Nano Research 2019年第5期12卷 1193-1197页

作者： Xiao-Fei Yu Dong-Xu Tian Wen-Cui Li Bin He Yu Zhang Zhi-Yuan Chen An-Hui Lu State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian 116024China

Lithium sulfur battery has been identified as a promising candidate for next storage devices attributing to ultrahigh energy density.However,non-conductive nature of sulfur and shuttling effect of soluble lithium polysulfides are intractable remaining problems.Herein,we develop a highly conductive nickel-rich Ni12P5/CNTs hybrid with high specific surface area as sulfur host to address these issues.The polar nature of Ni12Ps/CNTs can significantly relieve the shuttle effect by means of a strong affinity towards lithium polysulfides and enhance kinetics of polysulfides redox reactions.In addition,the Ni12P5/CNTs with a superior conductivity (500 S·m^-1) and high surface area of 395 m^2·g^-1 enables the effective electron transfer and expedited interfacial reaction.As a result,Ni12P5/CNTs hosted sulfur cathode exhibits high rate capability (784 mAh·g^-1 at 4 C) and stable cycling performance with a negligible capacity fading of 0.057 % per cycle over 1,000 cycles at 0.5 C.This work paves an alternative way for designing high performance sulfur cathodes involved metal-rich phosphides.

关键词： Ni-rich phosphides carbon nanotu behigh conductivity catalytic effect lithium sulfur battery

Interfacial Behavior of sulfur and Yttrium in Yttrium Modified Ni _3Al Based Alloy IC6 during High Temperature Oxidation Process

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Journal of Rare Earths 2000年第2期18卷 124-127页

作者：肖程波韩雅芳 Beijing Institute of Aeronautical Materials Beijing 100095 China

The interfacial behavior of sulfur and yttrium in the yttrium modified Ni 3Al based alloy IC6 during oxidation at 1100 ℃ was analyzed by X ray line scan of electron probe microstructural analysis(EPMA). The results show that the migration and segregation of sulfur to the interface between oxide scale and the substrate at high temperature is retarded owing to the presence of yttrium. This is attributed to the desulfurization by yttrium in the melt and the trapping of sulfur by yttrium rich phases during oxidation, which leads to improving the coherence between oxide scale and substrate. Another reason of increasing the high temperature oxidation resistance of alloy IC6 by the addition of yttrium is that yttrium migrates to the grain boundaries of oxides during oxidation and hence improve their strength. This results in the transformation of the oxide scale spallation cracks from intergranular cracks for alloy without yttrium to transgranular ones for yttrium modified alloy.

关键词： rare earths sulfur yttrium Ni 3Al high temperature oxidation interfacial behavior

Novel boron-and sulfur-doped polycyclic aromatic hydrocarbon as multiple resonance emitter for ultrapure blue thermally activated delayed fluorescence polymers

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Science China Chemistry 2021年第4期64卷 547-551页

作者： Fan Chen Lei Zhao Xingdong Wang Qingqing Yang Weili Li Hongkun Tian Shiyang Shao Lixiang Wang Xiabin Jing Fosong Wang State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Boron(B)-and sulfur(S)-doped polycyclic aromatic hydrocarbons(PAHs)are developed as a novel kind of multiple resonance emitters for ultrapure blue thermally activated delayed fluorescence(TADF)polymers with narrowband electroluminescence.The combination of electron-deficient B atom and electron-rich S atom in PAH can form an intramolecular push-pull electronic system in a rigid aromatic framework,leading to reduced singlet-triplet energy splitting and limited structure relaxation of excited states.The critical roles of S atom in determining emission properties with respect to the oxygen analogues are in two aspects:(i)reducing energy bandgap to shift emission from human-eye-insensitive ultraviolet zone to blue region,and(ii)promoting reverse intersystem crossing process by heavy-atom effect to activate TADF effect.The resulting polymer containing B,S-doped PAH as emitter and acridan as host exhibits efficient blue electroluminescence at 458 nm with small full-width at halfmaximum of 31 nm,representing the first example for ultrapure TADF polymer with narrowband electroluminescence.

关键词： polycyclic aromatic hydrocarbon boron sulfur multiple resonance thermally activated delayed fluorescence

sulfur Distribution during Hydrothermal Liquefaction of Lignite, Wheat Straw and Plastic Waste in Sub-Critical Water

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China Petroleum Processing & Petrochemical Technology 2015年第1期17卷 24-30页

作者： Wang Baofeng Huang Yaru Zhang Jinjun School of Chemistry & Material Science Shanxi Normal University

The distribution and transformation of sulfur in products during hydrothermal liquefaction of lignite, wheat straw and plastic waste in sub-critical water were investigated in an autoclave. The influence of blending ratio, temperature, initial nitrogen pressure, residence time and additives on sulfur distribution was studied systematically. The results showed that most of sulfur existed as organic sulfur and transferred into the residue, and only a small part of sulfur transferred into oil and gas during hydrothermal liquefaction of lignite, wheat straw and plastic waste in sub-critical water. The results also showed that lower temperature(less than 300 ℃) was favorable for obtaining oil with low sulfur content. It can be also seen from the results that the best condition to obtain the oil with low sulfur content should be implemented at a lignite/wheat straw/plastic waste blending ratio of 5:4:1, an initial nitrogen pressure of 3 MPa and a residence time of 30 minutes. Furthermore, the results indicated that adding tourmaline during hydrothermal liquefaction of lignite, wheat straw and plastic waste was beneficial to production of oil with low sulfur content.

关键词： lignite, wheat straw, plastic waste, hydrothermal liquefaction, sulfur

Oscillator Strength for n = 2 Transitions in Highly Ionized sulfur

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Chinese Physics Letters 2005年第5期22卷 1099-1101页

作者：杨治虎杜树斌常宏伟张小安苏弘张艳萍宋张勇 InstituteofModernPhysics ChineseAcademyofSciencesLanzhou730000 ChinaInstituteofAtomicEnergy Beijing102413 不详 InstituteofModernPhysics ChineseAcademyofSciencesLanzhou730000//DepartmentofPhysicsXianyangTeachersCollegeXianyang712000

Oscillator strength f-values for L-shell transitions in highly ionized sulfur are studied by the beam–foil technique at the HI-13 tandem accelerator in China Institute of Atomic Energy. The lifetimes of the upper levels 2s2p 1Po1, 2p2 1S0, 2p2 3P1, 2p2 3P2, 2p2 3P0 of Be-like sulfur are measured to be 129±4, 81±5, 165±7, 159±8, 176±11ps. By using the measured lifetimes, the f-values are calculated to be 0.074, 0.082, 0.060, 0.066, 0.229, 0.056, 0.083, 0.089, 0.028 for the transitions 2s22p2 3P1–2s2p3 3Po1, 2s22p 2Po3/2–2s2p2 2P1/2, 2s2p2 4P3/2–2p3 4So3/2, 2s22p 2Po1/2–2s2p2 2D3/2, 2s2 1S0–2s2p 1Po1, 2s2p1Po1–2p2 1S0, 2s2p3Po0–2p2 3P1, 2s2p 3Po2–2p2 3P2 and 2s2p 3Po1–2p2 3P0. Most of the experimental results are in agreement with theoretical studies, but differ slightly from the previous experimental data.

关键词： sulfur

Spectra of Highly Ionized sulfur below 200 ^。A

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Chinese Physics Letters 2004年第2期21卷 287-290页

作者：杨治虎王友德马新文刘惠萍苏弘张艳萍肖国青 InstituteofModernPhysics ChineseAcademyofSciencesPOBox31Lanzhou730000

Spectra of carbon-, boron-, beryllium-, lithium-, helium-, and hydrogen-like sulfur ions were obtained and studied for the wavelengths below 200Åand the energy of 80MeV by using beam-foil method. Thirty-five lines have been identified, in which 15 lines are newly accurately measured. The spectra were analysed based on the theoretical results and other experimental data.

关键词： sulfur