We report the synthesis of porous LiFePO4/NiP composite nanospheres and their application in rechargeable lithium-ion batteries.A simple one-step spraying technique was developed to prepare LiFePO_(4)/NiP composite nanospheres with an electrical conductivity 10^(3)-10^(4) times that of bulk particles of LiFePO_(4).Electrochemical measurements show that LiFePO_(4) nanospheres with a uniform loading of 0.86 wt%1.50 wt%NiP exhibit high discharge capacity,good cycling reversibility,and low apparent activation energies.The superior electrode performance of the as-prepared composite nanospheres results from the greatly enhanced electrical conductivity and porous structure of the materials.
Mg micro/nanoscale materials with sphere-like morphologies are prepared via a vapor-transport deposition process. The structure and morphology of the asprepared products are characterized by powder X-ray diffraction and scanning electron microscopy. Vapor-liquid-solid mechanism is proposed to explain the formation of Mg micro/nanospheres on the basis of the experimental results.
Use of free air as oxidant and copper(II)chloride as catalyst,3,3'-di-tert-butylbi-phenyl-2,5,2',5'-diquinone(BBDQ)was prepared via catalytic oxidation of 2,2'-dihydroxy-3,3'-di-tert-butyl-5,5'-dimethoxy-biphenyl(di-BHA).The yield of reaction attained 95% and the selectivity for BBDQ was 100%.The single-crystal X-ray diffraction analysis reveals that the dihedral angle between two rings(benzene rings for di-BHA and quinone rings for BBDQ)changes from 89.8 to 45.3o,indicating the steric hindrance effects of methyl disappear in the oxidation process.The crystal structures of di-BHA and BBDQ are further confirmed by their spectral characterizations.The probable mechanism for this oxidation process is also discussed.
A novel and simple approach is reported to fabricate uniform single-crystal ZnO nanorods in ionic liq-uids. The as-obtained ZnO nanorods have been characterized by XRD,TEM,HRTEM,SAED,XPS,EDXA,PL and UV-vis absorption spectra. The rod diameters of the nanostructures can be controlled by tuning the amount of sodium hydroxide in the synthesis. Photoluminescence results show that the nanos-tructural ZnO exhibits better optical properties than bulk ZnO does and interestingly,the smaller the rod diameters are,the better optical property 1D nanostructural ZnO exhibits. The possible growth mechanism of ZnO nanorods is also investigated.
Nanometer SnO2 particles were synthesized by sol-gel dialytic processes and used as a support to prepare CuO supported catalysts via a deposition-precipitation method. The samples were characterized by means of TG-DTA,XRD,H 2-TPR and XPS. The catalytic activity of the CuO/TiO2-SnO2 catalysts was markedly depended on the loading of CuO,and the optimum CuO loading was 8 wt.%(T 100 = 80 C) . The CuO/TiO2-SnO2 catalysts exhibited much higher catalytic activity than the CuO/TiO 2 and CuO/SnO 2 catalysts. H 2-TPR result indicated that a large amount of CuO formed the active site for CO oxidation in 8 wt.% CuO/TiO2-SnO2 catalyst.
Kairong Li Yaojie Wang Shurong Wang Baolin Zhu Shoumin Zhang Weiping Huang Shihua Wu
