MnxNi0.5-xZn0.5Fe2O4 nanorods were successfully synthesized by the thermal treatment of rod-like precursors that were fabricated by the co-precipitation of Mn2＋, Ni2＋, and Fe2＋ in the lye. The phase, morphology, an...MnxNi0.5-xZn0.5Fe2O4 nanorods were successfully synthesized by the thermal treatment of rod-like precursors that were fabricated by the co-precipitation of Mn2＋, Ni2＋, and Fe2＋ in the lye. The phase, morphology, and particle diameter were examined by the X-ray diffraction and transmission electron microscopy. The magnetic properties of the samples were studied using a vibrating sample magnetometer. nanorods with a diameter of 35 nm and an The results indicated that pure Ni0.5-xZn0.5Fe2O4 aspect ratio of 15 were prepared. It was found that the diametei of the MnxNi0.5-xZn0.5Fe2O4（0≤x≤0.5） samples increased, the length and the aspect .ratio decreased, with an increase in x value. When x=0.5, the diameter and the aspect ratio of the sample reached up to 50 nm and 7-8, respectively. The coercivity of the samples first increased and then decreased with the increase in the x value. The coercivity of the samples again increased when the x value was higher than 0.4. When x=0.5, the coercivity of the MnxNi0.5-xZn0.5Fe2O4 sample reached the maximal value （134.3 Oe） at the calcination temperature of 600 ℃. The saturation magnetization of the samples first increased and then. decreased with the increase in the x value. When x=0.2, the saturation magnetizat：ion of the sample reached the maximal value （68.5 emu/g） at the calcination temperature of 800 ℃.展开更多
The hydrothermal synthesis of single-crystallineβ-MnO2 nanorods and their chemical conversion into single-crystalline LiMn2O4 nanorods by a simple solid-state reaction were reported.This method has the advantages of ...The hydrothermal synthesis of single-crystallineβ-MnO2 nanorods and their chemical conversion into single-crystalline LiMn2O4 nanorods by a simple solid-state reaction were reported.This method has the advantages of producing pure,single-phase and crystalline nanorods.The LiMn2O4 nanorods have an diameter of about 300 nm.The discharge capacity and cyclic performance of the batteries were investigated.The LiMn2O4 nanorods show better cyclic performance with a capacity retention ratio of 86.2% after 100 cycles.Battery cyclic studies reveal that the prepared LiMn2O4 nanorods have high capacity with a first discharge capacity of 128.7 mA·h/g.展开更多
We report the fabrication and photocatalytic property of a composite of C/CaFe2O4nanorods(NRs)in an effort to reveal the influence of carbon modification.It is demonstrated that the photocatalytic degradation activity...We report the fabrication and photocatalytic property of a composite of C/CaFe2O4nanorods(NRs)in an effort to reveal the influence of carbon modification.It is demonstrated that the photocatalytic degradation activity is dependent on the mass ratio of C to CaFe2O4.The optimal carbon content is determined to be58wt%to yield a methylene blue(MB)degradation rate of0.0058min.1,which is4.8times higher than that of the pristine CaFe2O4NRs.The decoration of carbon on the surface of CaFe2O4NRs improves its adsorption capacity of the MB dye,which is specifically adsorbed on the surface as a monolayer according to the adsorption isotherm analysis.The trapping experiments of the reactive species indicate that superoxide radicals(.O2)are the main active species responsible for the removal of MB under visible‐light irradiation.Overall,the unique feature of carbon coating enables the efficient separation and transfer of photogenerated electrons and holes,strengthens the adsorption capacity of MB,and improves the light harvesting capability,hence enhancing the overall photocatalytic degradation of MB.展开更多
The thermal decomposition processes in solid state CoC2O4·2H2O have been studied in air using TG/DTA, DSC and XRD techniques. TG/DTA, DSC curves showed that the decomposition proceeded through two well-defined st...The thermal decomposition processes in solid state CoC2O4·2H2O have been studied in air using TG/DTA, DSC and XRD techniques. TG/DTA, DSC curves showed that the decomposition proceeded through two well-defined steps in air. Mass loss of the thermal decomposition of CoC2O4·2H2O was in good agreement with the theoretica1 one. XRD showed that the final product of the thermal decomposition was Co3O4. The activation energies were calculated through the ASTM E698 and Flynn-Wall-Ozawa (FWO) methods, and the possible conversion functions had been estimated through the multiple-linear regression method. The activation energies for the two steps decomposition of CoC2O4·2H2O were 140.18 kJ·mol-1 and 134.61 kJ·mol-1, respective1y.展开更多
Both whisker and nanometer MgSO4·5Mg(OH)2·3H2O(MOS) were prepared by hydrothermal method at 140℃for different times, using NaOH and MgSO4·7H2O as raw materials. The MgSO4·5Mg(OH)2·3H2O part i...Both whisker and nanometer MgSO4·5Mg(OH)2·3H2O(MOS) were prepared by hydrothermal method at 140℃for different times, using NaOH and MgSO4·7H2O as raw materials. The MgSO4·5Mg(OH)2·3H2O part icles were characterized by powder X ray diffraction(XRD),thermal analysis(TGA DSC), infrared spectroscopy(FT IR),transmission electron microscopy(SEM) and scanning electron microscopy(TEM). The size distribution in whisker like and nanocrystalline materials arein the range of 10～50μm and 10～20nm respectively. The whisker MOS is metastable phase in MgSO4 NaOH H2O system at 140℃,whereas nanometer MOS is stable phase.展开更多
文摘MnxNi0.5-xZn0.5Fe2O4 nanorods were successfully synthesized by the thermal treatment of rod-like precursors that were fabricated by the co-precipitation of Mn2＋, Ni2＋, and Fe2＋ in the lye. The phase, morphology, and particle diameter were examined by the X-ray diffraction and transmission electron microscopy. The magnetic properties of the samples were studied using a vibrating sample magnetometer. nanorods with a diameter of 35 nm and an The results indicated that pure Ni0.5-xZn0.5Fe2O4 aspect ratio of 15 were prepared. It was found that the diametei of the MnxNi0.5-xZn0.5Fe2O4（0≤x≤0.5） samples increased, the length and the aspect .ratio decreased, with an increase in x value. When x=0.5, the diameter and the aspect ratio of the sample reached up to 50 nm and 7-8, respectively. The coercivity of the samples first increased and then decreased with the increase in the x value. The coercivity of the samples again increased when the x value was higher than 0.4. When x=0.5, the coercivity of the MnxNi0.5-xZn0.5Fe2O4 sample reached the maximal value （134.3 Oe） at the calcination temperature of 600 ℃. The saturation magnetization of the samples first increased and then. decreased with the increase in the x value. When x=0.2, the saturation magnetizat：ion of the sample reached the maximal value （68.5 emu/g） at the calcination temperature of 800 ℃.
基金Project(2008AA031205)supported by the National High-tech Research and Development Program of China
文摘The hydrothermal synthesis of single-crystallineβ-MnO2 nanorods and their chemical conversion into single-crystalline LiMn2O4 nanorods by a simple solid-state reaction were reported.This method has the advantages of producing pure,single-phase and crystalline nanorods.The LiMn2O4 nanorods have an diameter of about 300 nm.The discharge capacity and cyclic performance of the batteries were investigated.The LiMn2O4 nanorods show better cyclic performance with a capacity retention ratio of 86.2% after 100 cycles.Battery cyclic studies reveal that the prepared LiMn2O4 nanorods have high capacity with a first discharge capacity of 128.7 mA·h/g.
基金supported by the National Natural Science Foundation of China(21503100)Natural Science Foundation of Jiangxi Province(20161BAB213071,20151BAB213010)+1 种基金Project of Education Department of Jiangxi Province(GJJ150325)Sponsored Program for Cultivating Youths of Outstanding Ability in Jiangxi Normal University~~
文摘We report the fabrication and photocatalytic property of a composite of C/CaFe2O4nanorods(NRs)in an effort to reveal the influence of carbon modification.It is demonstrated that the photocatalytic degradation activity is dependent on the mass ratio of C to CaFe2O4.The optimal carbon content is determined to be58wt%to yield a methylene blue(MB)degradation rate of0.0058min.1,which is4.8times higher than that of the pristine CaFe2O4NRs.The decoration of carbon on the surface of CaFe2O4NRs improves its adsorption capacity of the MB dye,which is specifically adsorbed on the surface as a monolayer according to the adsorption isotherm analysis.The trapping experiments of the reactive species indicate that superoxide radicals(.O2)are the main active species responsible for the removal of MB under visible‐light irradiation.Overall,the unique feature of carbon coating enables the efficient separation and transfer of photogenerated electrons and holes,strengthens the adsorption capacity of MB,and improves the light harvesting capability,hence enhancing the overall photocatalytic degradation of MB.
文摘The thermal decomposition processes in solid state CoC2O4·2H2O have been studied in air using TG/DTA, DSC and XRD techniques. TG/DTA, DSC curves showed that the decomposition proceeded through two well-defined steps in air. Mass loss of the thermal decomposition of CoC2O4·2H2O was in good agreement with the theoretica1 one. XRD showed that the final product of the thermal decomposition was Co3O4. The activation energies were calculated through the ASTM E698 and Flynn-Wall-Ozawa (FWO) methods, and the possible conversion functions had been estimated through the multiple-linear regression method. The activation energies for the two steps decomposition of CoC2O4·2H2O were 140.18 kJ·mol-1 and 134.61 kJ·mol-1, respective1y.
文摘Both whisker and nanometer MgSO4·5Mg(OH)2·3H2O(MOS) were prepared by hydrothermal method at 140℃for different times, using NaOH and MgSO4·7H2O as raw materials. The MgSO4·5Mg(OH)2·3H2O part icles were characterized by powder X ray diffraction(XRD),thermal analysis(TGA DSC), infrared spectroscopy(FT IR),transmission electron microscopy(SEM) and scanning electron microscopy(TEM). The size distribution in whisker like and nanocrystalline materials arein the range of 10～50μm and 10～20nm respectively. The whisker MOS is metastable phase in MgSO4 NaOH H2O system at 140℃,whereas nanometer MOS is stable phase.
