Mixed transition metal oxides （MTMOs） have received intensive attention as promising anode materials for lithium-ion batteries （LIBs） and sodium-ion batteries （SIBs）. In this work, we demonstrate a facile one-st...Mixed transition metal oxides （MTMOs） have received intensive attention as promising anode materials for lithium-ion batteries （LIBs） and sodium-ion batteries （SIBs）. In this work, we demonstrate a facile one-step water-bath method for the preparation of graphene oxide （GO） decorated Fe2（MoO4）3 （FMO） microflower composite （FMO/GO）, in which the FMO is constructed by numerous nanosheets. The resulting FMO/GO exhibits excellent electrochemical performances in both LIBs and SIBs. As the anode material for LIBs, the FMO/GO delivers a high capacity of 1,220 mAh·g^-1 at 200 mA·g^-1 after 50 cycles and a capacity of 685 mAh·g^-1 at a high current density of 10 A·g^-1. As the anode material for SIBs, the FMO/GO shows an initial discharge capacity of 571 mAh·g^-1 at 100 mA·g^-1, maintaining a discharge capacity of 307 mAh·g^-1 after 100 cycles. The promising performance is attributed to the good electrical transport from the intimate contact between FMO and graphene oxide. This work indicates that the FMO/GO composite is a promising anode for high-performance lithium and sodium storage.展开更多
In H2/N2 atmosphere, the reduction behavior of the stoichiometric compound, Fe2(MoO4)3, was studied by in-situ Mossbauer spectroscopy (in-situ MBS), temperature-programmed reduction (TPR) and X-ray diffraction (XRD). ...In H2/N2 atmosphere, the reduction behavior of the stoichiometric compound, Fe2(MoO4)3, was studied by in-situ Mossbauer spectroscopy (in-situ MBS), temperature-programmed reduction (TPR) and X-ray diffraction (XRD). The results showed that the reduction products, β-FeMoO4, Mo4O11, MoO2, Fe3O4, Fe2Mo3O8, Fe and Mo, as well as iron-molybdenum alloys, were formed subsequently when the reduction temperature was raised. It was found that when Mo6+ were reduced to Mo4+, Fe2+ were oxidized to Fe3+. Due to the interactions among the metal ions and the electron transfers, the reduction processes of the metal ions in Fe2(MoO4)3 are very complex. According to the results of XRD and MBS obtained at various TPR stages, the reaction equations for the reduction stages were proposed. The Mossbauer spectrum of an intermediate species, Fe2Mo3O8, was found to exhibit two doublets, with I.S.=0.90mm/s and Q.S. =0.58 mm/s, and I.S. = 1.02mm/s and Q.S. = 1.04mm/s, respectively.展开更多
Fe2(MoO4)3 ultrafine particle catalyst has been prepared successfully by the sol-gel process at lower temperature. The influences of preparation conditions and thermal treatment conditions on the morphology and struct...Fe2(MoO4)3 ultrafine particle catalyst has been prepared successfully by the sol-gel process at lower temperature. The influences of preparation conditions and thermal treatment conditions on the morphology and structure of the ultrafine particle catalyst has been studied by using TEM, DTA-TG, FT-IR, XRD and BET surface area measurement methods. It is shown that the BET surface area of Fe2(MoO4)3 ultrafine particle prepared by sol-gel method is much larger than that of Fe2(MoO4)3 prepared by coprecipitation method. For the preparation of the welldistribuated Fe2(MoO4)3 ultrafine particles with the size in the range of 40-80nm, the optimumconditions are : treatment temperature <673K, L/M (Citric acid/Metallic ions)=0.3 and pH<1 .0.展开更多
文摘以Fe Cl3·7H2O和Na2Mo O4为原料,采用水热合成法制备三维花状Fe2(Mo O4)3微米球。探讨不同合成温度对样品形貌的影响,利用XRD、SEM和EDS等分析技术对样品的结构、形貌进行了表征,对该材料的电化学性能进行了测试。结果表明:Fe2(Mo O4)3微米球是由二维纳米片自组装而成的花状结构,合成温度为160℃时,制备的样品具有良好的电化学性能,当电流密度为100 m A·g-1,首次放电比容量为1 431 m Ah·g-1;并具有较好的循环性能和倍率性能。并对160℃合成样品表现较好电化学性能的原因进行了探讨。
基金This work was supported by the National Key Research and Development Program of China （No. 2016YFA0202603）, the National Basic Research Program of China （No. 2013CB934103）, the Programme of Introducing Talents of Discipline to Universities （No. B17034）, the National Natural Science Foundation of China （Nos. 51521001, 21673171, 51502226, and 51302203）, the National Natural Science Fund for Distinguished Young Scholars （No. 51425204）, and the Fundamental Research Funds for the Central Universities （WUT： 2016III001, 2016III002, 2016III006）.Thanks to Prof. Zhaoping Liu and Prof. Xufeng Zhou at Ningbo Institute of Material Technology and Engineering of Chinese Academy of Sciences for providing the graphene oxide. Prof. Liqiang Mai gratefully acknowledged financial support from China Scholarship Council （No. 201606955096）.
文摘Mixed transition metal oxides （MTMOs） have received intensive attention as promising anode materials for lithium-ion batteries （LIBs） and sodium-ion batteries （SIBs）. In this work, we demonstrate a facile one-step water-bath method for the preparation of graphene oxide （GO） decorated Fe2（MoO4）3 （FMO） microflower composite （FMO/GO）, in which the FMO is constructed by numerous nanosheets. The resulting FMO/GO exhibits excellent electrochemical performances in both LIBs and SIBs. As the anode material for LIBs, the FMO/GO delivers a high capacity of 1,220 mAh·g^-1 at 200 mA·g^-1 after 50 cycles and a capacity of 685 mAh·g^-1 at a high current density of 10 A·g^-1. As the anode material for SIBs, the FMO/GO shows an initial discharge capacity of 571 mAh·g^-1 at 100 mA·g^-1, maintaining a discharge capacity of 307 mAh·g^-1 after 100 cycles. The promising performance is attributed to the good electrical transport from the intimate contact between FMO and graphene oxide. This work indicates that the FMO/GO composite is a promising anode for high-performance lithium and sodium storage.
基金Project supported by the Science Fund of the Chinese Academy of Sciencesthe Trans-century Training Program Foundation for the Talents by the State Education Commission of Chinathe Measurement Fund from the Modern Analysis Center of the Nanjing Univer
文摘In H2/N2 atmosphere, the reduction behavior of the stoichiometric compound, Fe2(MoO4)3, was studied by in-situ Mossbauer spectroscopy (in-situ MBS), temperature-programmed reduction (TPR) and X-ray diffraction (XRD). The results showed that the reduction products, β-FeMoO4, Mo4O11, MoO2, Fe3O4, Fe2Mo3O8, Fe and Mo, as well as iron-molybdenum alloys, were formed subsequently when the reduction temperature was raised. It was found that when Mo6+ were reduced to Mo4+, Fe2+ were oxidized to Fe3+. Due to the interactions among the metal ions and the electron transfers, the reduction processes of the metal ions in Fe2(MoO4)3 are very complex. According to the results of XRD and MBS obtained at various TPR stages, the reaction equations for the reduction stages were proposed. The Mossbauer spectrum of an intermediate species, Fe2Mo3O8, was found to exhibit two doublets, with I.S.=0.90mm/s and Q.S. =0.58 mm/s, and I.S. = 1.02mm/s and Q.S. = 1.04mm/s, respectively.
文摘Fe2(MoO4)3 ultrafine particle catalyst has been prepared successfully by the sol-gel process at lower temperature. The influences of preparation conditions and thermal treatment conditions on the morphology and structure of the ultrafine particle catalyst has been studied by using TEM, DTA-TG, FT-IR, XRD and BET surface area measurement methods. It is shown that the BET surface area of Fe2(MoO4)3 ultrafine particle prepared by sol-gel method is much larger than that of Fe2(MoO4)3 prepared by coprecipitation method. For the preparation of the welldistribuated Fe2(MoO4)3 ultrafine particles with the size in the range of 40-80nm, the optimumconditions are : treatment temperature <673K, L/M (Citric acid/Metallic ions)=0.3 and pH<1 .0.
