A unique metal-organic framework [Cd2(L)1.5(μ3-OH)(H2 O)2 ]·2H2 O(1, H2 L = 2,5-dibenzoylterephthalic acid) has been synthesized under hydrothermal conditions, and characterized by single-crystal X-ray diffractions, elemental analyses, IR spectra and fluorescence spectrum. The compound is of triclinic system, space group P1, C33 H27 CdO14, Mr = 870.33, a = 12.2939(17), b = 12.5135(9), c = 13.2046(10), α = 115.3190(10), β = 96.9140(10), γ = 109.7950(10)°, V = 1641.6(3)3, Z = 2, Dc = 1.761 g/cm3, F(000) = 862, μ(MoK) = 1.366 mm-1, Rint = 0.0148, R = 0.0240 and wR = 0.0639 for 5995 observed reflections with I > 2σ(I). X-ray analysis shows that the title complex exhibits a 3D framework with(412·63) topology, in which the tetra-nuclear [Cd4(μ3-OH)2 ] clusters act as 6-connected nodes, and the L ligands can be simplified to be linear connectors. Moreover, the thermal stability and fluorescence have been studied in detail.
采用溶胶凝胶法合成Ce0.8Nd0.2O1.9(NDC)粉体,分别将1%(x,摩尔分数)的过渡金属氧化物(Transitional Metal Oxides,TMOs)MnO2,FeO1.5或CoO添加到NDC粉体中,经10MPa压片后于1 300℃烧结6h。用X射线衍射(XRD)和场发射扫描电子显微镜(FE-SEM)对样品进行结构表征,采用交流阻抗谱(AC)测试样品导电性能。结果表明,MnO2,Fe2O3或CoO对NDC均可有效促进样品的致密化,增加相对致密度和提高NDC的晶粒电导率;1%(x)MnO2或1%(x)CoO的掺杂对NDC的晶界电导率产生有害的影响,掺杂1%(x)FeO1.5对NDC晶界杂质SiO2有一定的清除作用,提高晶界电导率。Fe2O3不仅是一种良好的烧结助剂,而且是一种有效的晶界清除剂。
Ce6-xHoxMoO15-δ(0.0≤x≤1.2) was synthesized by modified sol-gel method and characterized by diffe-rential X-ray diffraction(XRD),Raman,and X-ray photoelectron spectroscopy(XPS) methods.The oxide ionic con-ductivity of the samples was investigated by AC impedance spectroscopy.It shows that all the samples are single phase with a cubic fluorite structure.The solid solution Ce6-xHoxMoO15-δ(x=0.6) was detected to be the best con-ducting phase with the highest conductivity(σt=1.05×10-2 S/cm) at 800 oC and the lowest activation energy(Ea=1.09 eV).These properties suggest that this kind of material has a potential application in intermediate-low temperature solid oxide fuel cells.
