壳聚糖/Pb(Ⅱ)模板壳聚糖膜与Pb(Ⅱ)螯合反应的动力学及机理探讨

Chitosan and chitosan membranes with Pb(Ⅱ) ion as template were studied. The adsorption isotherms were correlated by dc/dt=-kcⁿ at the temperature of 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃. By means of linear correlation, the shapes of the isotherm curves were similar to the kinetic function of 2/c^1/2=-kt and the apparent activation energy for with chitosan(123.8 kJ·moL^-1) was larger than that of membrane with Pb(Ⅱ) ion(92.3kJ·moL^-1). The chitosan membrane with Pb(Ⅱ) ion template was better “memory” function. The adsorption mechanism of chitosan with Pb(Ⅱ) was studied by IR and XPS. The results indicated that the nitrogen in -NH₂ and the oxygen in C₃-OH of chitosan were coordination atoms.     

有机溶液中电化学制备纳米MgTiO3

In a cell without separating the cathode and anode spaces, the precursor MgTi(OCH₂CH₃)_(6-y)(acac)_y of the mixed oxide MgTiO₃ was directly synthesized by electrochemical dissolution of titanium for 4 hours and then of magnesium for 1 hour 40 minutes at the current of 0.2 A in ethanol and acetyl-acetone solution. The nano- MgTiO₃ powder was prepared by a direct sol-gel process of the electrolyte solution under pH≈8.5 followed by washing, drying in vacuum for 24 h, and calcination at 500 ℃ for 2 h. IR and Raman spectroscopy, XRD, and TEM were used to investigate the structure of nano-MgTiO₃ and its precursor. The result suggested that it was more appropriate to control the temperature between 35～40 ℃ and the concentration of conductive additive (Bu₄N)Br at 0.04 mol·L^-1. The xerogel with an average particle size of 12 nm and the nano-MgTiO₃ of 20 nm was thus obtained in a high purity.     

锂离子电池正极材料LiNi1-xCoxO2的合成及电化学性能研究

LiNi_1-xCo_xO₂ cathode materials for lithium ion batteries were synthesized by the co-precipitation and solid-state reaction methods with LiOH·H₂O, Ni(NO₃)₂·6H₂O and Co(NO₃)₂·6H₂O as raw materials. The materials were characterized by XRD, SEM and electrochemical tests. The results showed that synthesized cathode materials were with layered structure similar to α-NaFeO₂ and uniform morphology and nearly normal grain size distribution and better electrochemical performance when x was 0.18. The first charge and discharge capacity of the cathode material was 224.3 mAh·g^-1 and 194.2 mAh·g^-1, respectively. 88.5% of the first discharge capacity remained at the 20th cycle.     

具有二维网格结构的5-(4-硝基苯基)四唑-锌(Ⅱ)配合物

A zinc(Ⅱ) complex [(5-(4-nitrophenyl)tetrazolato)₂Zn]_n was obtained by the hydrothermal treatment of ZnBr₂ and NaN₃ with 4-nitrobenzonitril in water at 120 ℃ in Pyrex tube. The crystal belongs to orthorhombic system with space group Pbcn, and a=1.040 7(5) nm, b=1.382 1(7) nm, c=2.435 1(13) nm, V=3.503(3) nm³, Z=8. This complex is a good blue fluorescent material in solid state at room temperature. CCDC: 684226.     

Na掺杂对锆酸锂吸收CO2性能的影响

By using Li₂CO₃, ZrO₂, and Na₂CO₃ as starting materials, sodium-doped Li_2(1-x)Na_2xZrO₃ absorbents were prepared by high-temperature solid-state reaction. The crystal structure of the lithium zirconate material was analyzed using a X-ray powder diffractometer (XRD), the microstructure of all the samples was observed using the method of scanning electron microscopy (SEM) and the CO₂-absorption ability of the lithium zirconate material was studied using a thermogravimetric analyzer (TG). It was found that Li_2(1-x)Na_2xZrO₃ absorbent with x=0.02 possesses the best performance. As much as (25 ± 0.4)% (wt) of CO₂ was absorbed by such an absorbent in an atmosphere consisting of 20% (wt) CO₂ and 80% (wt) air at 500 ℃ within 3 h. After 10 cycles of absorption-desorption this absorbent lost only 0.9% of its CO₂-absorption capacity. No remarkable change in particle size and pH was observed.     

Si5P6O25∶Tb3+的结构与荧光性质

Tb³⁺ ions were incorporated in P-Si matrix material through a sol-gel process. Luminescence properties of Tb³⁺ as a function of dopant， firing temperature， composition and structure of matrices were investigated. The gels synthesized by the reaction of P₂O₅ or H₃PO₄ with tetraethoxy silane and TbCl₃ as dopant were fired in air from the temperature 25～1000℃ to form P-Si crystalline phase. The crystal structure was determined by powder X-ray diffraction. Si₅O(PO₄)₆ were the only crystalline phase and belong to hexagonal crystal system. The emission of ⁵D₄-⁷F₅(～545nm) transition of Tb³⁺ in the P-Si system is composed of two peaks. The amount of doping Tb³⁺ varied from 0.664% to 1.644%， and no obvious concentration quenching was observed in this doping concentra-tion range. The intensity of Tb³⁺ emission increased with firing temperature increasing and becomes stable at 800～1000℃.     

ZrWO4F2的前驱物法合成和表征

Zirconium tungsten oxyfluoride, ZrWO₄F₂, was firstly synthesized with the precursor route. The composition of the compound was determined by combining the results of ICP and XPS. The indexed powder X-ray diffraction pattern of this compound indicates that it is a pure phase, orthorhombic crystal system, space group D₂²=P2₁22 and a=15.32(2)?,b=13.877(7)?,c=8.42(2)?.Combining the results of the DTA-TGA curves from room temperature to 700℃ and XRD patterns in different temperatures the mechanism was revealed during the solid precursor (1) been heated to 700℃. The zirconium tungsten oxyfluoride was considered to be a metastable com-pound. The ascertaining of annealing time and temperature is the key of handling.     

[Mn(NH2NHCO2C2H5)3](NO3)2的晶体结构和热分解机理

[Mn(ECZ)₃](NO₃)₂ is newly prepared by the aqueous solutions of Mn(NO₃)₂ and ethyl carbazate (ECZ). The crystal structure has been determined by X-ray crystal diffraction analysis. It belongs to monoclinic with space group of P2₁/n. The crystal parameters are: a=1.3974(2) nm, b=0.8796(2) nm, c=3.4322(7) nm, β=91.25(1) °, V= 4.2175(1) nm³, Z=8. Its molecular weight is 491.30. Mn²⁺ is located on the center of the molecular structure. Ethyl carbazate serves as a bidentate ligand which coordinates to the metal cations with its carbonyl oxygen atom and the terminal hydrazine nitrogen atom, forming five-member chelating rings, and three such rings are formed in each molecule. The coordination number of the metal ion is six and the coordination configuration of the central ion is octahedral. Specially, antimer configuration phenomenon is found in the molecule. The complex is further characterized by element analysis and IR measurements. The thermal decomposition mechanism is studied by using TG-DTG and DSC techniques. CCDC: 215675.     

有机体系中电合成纳米PbTiO3粉体及表征

The precursor PbTi(OCH₂CH₃)_6-y(acac)_y for the mixed oxide PbTiO₃was synthesized by electrochemical dissolution of Lead and Titanium with a 1∶2 electricity quality in ethanol and acetyl-acetone solution. Nano-sized PbTiO₃powder was prepared by drying and calcining the xerogel from a direct sol-gel hydrolyzation of the precursor solution under pH of 8.5. The FTIR, TG-DTA, XRD and TEM were employed to characterize the structure of the precursor and nano-sized PbTiO₃. The results showed that the optimized conditions for the preparation of nano-sized PbTiO₃ were the electrolysis of the Lead plate and Titanium plate at 50 ℃ and 40 ℃ respectively under 0.03mol·dm^-3Bu₄NBr solution. The nano-sized PbTiO₃prepared by electrolysis exhibited a dispersive structure with an average diameter of 10 to 15 nm.     

稀土铜硫化合物TbCuS2的合成和晶体结构

Terbium copper disulfide, TbCuS₂, has been synthesized in the reaction of the elements in a KI flux at 850 ℃. The compound crystallizes in space group P2₁/c of the monoclinic system with four formula units in a cell of dimensions of a= 0.639 3(1) nm, b=0.702 5(1) nm, c=0.670 8(1) nm, β=98.097(4)°, and V=0.298 3(1) nm³ at 153 K. The structure comprises two-dimensional ²_∞[CuS₂] layers along [100] separated by the Tb atoms. In the structure, each Tb and Cu atoms are coordinated to seven and four S atoms, respectively. CSD: 415490.