Ba2Co9O14(BCO)是一种新型的电子-氧离子混合导体,在氧离子导体的固体氧化物燃料电池(SOFC)中,其作为阴极材料的应用可能性已经得到证实,本工作探索BCO在质子导体SOFC中的应用可能性。采用固相反应法制备BCO粉体,研究BCO与质子导体电解...Ba2Co9O14(BCO)是一种新型的电子-氧离子混合导体,在氧离子导体的固体氧化物燃料电池(SOFC)中,其作为阴极材料的应用可能性已经得到证实,本工作探索BCO在质子导体SOFC中的应用可能性。采用固相反应法制备BCO粉体,研究BCO与质子导体电解质BZCY(Ba Zr0.1Ce0.7Y0.2O3-δ)之间的化学相容性,分析BCO-BZCY复合阴极在BZCY电解质上的电化学性能。当复合阴极中BCO的质量含量为70%时,阴极性能最佳,界面阻抗活化能为1.26 e V。以BCO-BZCY为阴极,Ni-BZCY为阳极,BZCY为电解质的阳极支撑型单电池,700℃时,单电池的极化阻抗为0.15Ω·cm2,最大功率密度为400 m W·cm-2。展开更多
Ultrasmall near-monodisperse Ba2ErF7 nanocrystals with average crystal size 9.6 nm were synthesized with solvothermal method. The X-ray diffraction （XRD） and transmission electron microscopy （TEM） assays reveal th...Ultrasmall near-monodisperse Ba2ErF7 nanocrystals with average crystal size 9.6 nm were synthesized with solvothermal method. The X-ray diffraction （XRD） and transmission electron microscopy （TEM） assays reveal that the as-synthesized Ba2ErF7 nanocrystals are of the cubic structure with the cell parameter of 5.943 A, instead of the reported orthorhombic and tetragonal structure. Two emission bands originated from 2Hwj4H3/2 → 4F5/2 and 4F9/2 ----＋ 4115,2 of Er3＋ can be observed under a 980 nm laser excitation. The magnetic mass susceptibility of the as-synthesized BazErF7 nanocrystals reaches 4.293 × 10-5 emu g-1 Oe-1.展开更多
A new barium aluminoborate, Ba2Al4B6O17, has been synthesized by the hightemperature solution reaction at 780 ℃. The single-crystal XRD analysis shows that it crystallizes in triclinic space group P■ with a = 8.9601...A new barium aluminoborate, Ba2Al4B6O17, has been synthesized by the hightemperature solution reaction at 780 ℃. The single-crystal XRD analysis shows that it crystallizes in triclinic space group P■ with a = 8.9601(5), b = 9.1835(6), c = 10.6574(7) ?, a = 95.050(6)°, b = 111.569(5)°, g = 90.280(6)°, V = 811.71(9) ?3, Z = 2, Mr = 719.46, Dc = 2.944 g/cm3, μ = 5.127 mm-1, F(000) = 660, R = 0.0361 and wR = 0.0855 for 3846 observed reflections and 262 variables. This compound represents a new structure that features a three-dimensional [Al4B6O17]n4n- framework constructed by AlO4 tetrahedra, BO3 triangles, and B2O54-groups composed of two corner-sharing BO3 triangles, with intersecting open channels accommodating Ba2+ cations. It melts incongruently at 849 ℃. The existence of BO3 groups is confirmed by FT-IR and Raman spectra. The insulating nature with an optical band gap of about 3.50 eV is revealed by UV-VIS diffuse reflectance spectrum. Band structure calculations indicate that it is an indirect band material.展开更多
The structural, magnetic and electronic properties of the double perovskite Ba2SmNbO6 （for the simple cubic structure where no octahedral tilting exists anymore） are studied using the density functional theory withi...The structural, magnetic and electronic properties of the double perovskite Ba2SmNbO6 （for the simple cubic structure where no octahedral tilting exists anymore） are studied using the density functional theory within the generalized gradient approximation as well as taking into account the on-site Coulomb repulsive interaction. The total energy, the spin magnetic moment, the band structure and the density of states are calculated. The optimization of the lattice constants is 8.5173 A, which is in good agreement with the experimental value 8.5180 A. The calculations reveal that Ba2SmNbO6 has a stable ferromagnetic ground state and the spin magnetic moment per molecule is 5.00μB/f.u. which comes mostly from the Sin3＋ ion only. By analysis of the band structure, the compound exhibits the direct band gap material and half-metallic ferromagnetic nature with 100% spin-up polarization, which implies potential applications of this new lanthanide compound in magneto-electronic and spintronic devices.展开更多
文摘目的:制备高效稳定的分子筛,以满足高原地区和特殊地区的用氧需求。方法:采用离子交换改性法来提高分子筛的吸附能力。以应用广泛的4A型分子筛为原料,制备Ca2+、Ba2+交换改性的分子筛材料,并通过X射线衍射(X-ray diffraction,XRD)、扫描电子显微镜(scanning electron microscope,SEM)、红外光谱(infrared spectroscopy,IR)和BET(Brunner-Emmet-Teller)分析测试,观察分子筛的晶体结构和孔结构,得出Ba2+交换改性的特点。结果:Ca2+和Ba2+作为平衡阳离子能够交换到4A型分子筛中,经过Ca2+和Ba2+交换后分子筛比表面积增大,且分子筛仍为典型的微孔分子筛,孔体积变化不大。结论:该研究为制氧吸附剂性能的提高提供了新思路,为进一步研发高性能的制氧分子筛材料奠定了基础。
文摘Ba2Co9O14(BCO)是一种新型的电子-氧离子混合导体,在氧离子导体的固体氧化物燃料电池(SOFC)中,其作为阴极材料的应用可能性已经得到证实,本工作探索BCO在质子导体SOFC中的应用可能性。采用固相反应法制备BCO粉体,研究BCO与质子导体电解质BZCY(Ba Zr0.1Ce0.7Y0.2O3-δ)之间的化学相容性,分析BCO-BZCY复合阴极在BZCY电解质上的电化学性能。当复合阴极中BCO的质量含量为70%时,阴极性能最佳,界面阻抗活化能为1.26 e V。以BCO-BZCY为阴极,Ni-BZCY为阳极,BZCY为电解质的阳极支撑型单电池,700℃时,单电池的极化阻抗为0.15Ω·cm2,最大功率密度为400 m W·cm-2。
文摘Ultrasmall near-monodisperse Ba2ErF7 nanocrystals with average crystal size 9.6 nm were synthesized with solvothermal method. The X-ray diffraction （XRD） and transmission electron microscopy （TEM） assays reveal that the as-synthesized Ba2ErF7 nanocrystals are of the cubic structure with the cell parameter of 5.943 A, instead of the reported orthorhombic and tetragonal structure. Two emission bands originated from 2Hwj4H3/2 → 4F5/2 and 4F9/2 ----＋ 4115,2 of Er3＋ can be observed under a 980 nm laser excitation. The magnetic mass susceptibility of the as-synthesized BazErF7 nanocrystals reaches 4.293 × 10-5 emu g-1 Oe-1.
基金Supported by the National Natural Science Foundation of China under Grant No 50672087, and the National Basic Research Programme of China under Grant No 2006CB806000b.
基金Supported by the National Natural Science Foundation of China(No.20871012)
文摘A new barium aluminoborate, Ba2Al4B6O17, has been synthesized by the hightemperature solution reaction at 780 ℃. The single-crystal XRD analysis shows that it crystallizes in triclinic space group P■ with a = 8.9601(5), b = 9.1835(6), c = 10.6574(7) ?, a = 95.050(6)°, b = 111.569(5)°, g = 90.280(6)°, V = 811.71(9) ?3, Z = 2, Mr = 719.46, Dc = 2.944 g/cm3, μ = 5.127 mm-1, F(000) = 660, R = 0.0361 and wR = 0.0855 for 3846 observed reflections and 262 variables. This compound represents a new structure that features a three-dimensional [Al4B6O17]n4n- framework constructed by AlO4 tetrahedra, BO3 triangles, and B2O54-groups composed of two corner-sharing BO3 triangles, with intersecting open channels accommodating Ba2+ cations. It melts incongruently at 849 ℃. The existence of BO3 groups is confirmed by FT-IR and Raman spectra. The insulating nature with an optical band gap of about 3.50 eV is revealed by UV-VIS diffuse reflectance spectrum. Band structure calculations indicate that it is an indirect band material.
文摘The structural, magnetic and electronic properties of the double perovskite Ba2SmNbO6 （for the simple cubic structure where no octahedral tilting exists anymore） are studied using the density functional theory within the generalized gradient approximation as well as taking into account the on-site Coulomb repulsive interaction. The total energy, the spin magnetic moment, the band structure and the density of states are calculated. The optimization of the lattice constants is 8.5173 A, which is in good agreement with the experimental value 8.5180 A. The calculations reveal that Ba2SmNbO6 has a stable ferromagnetic ground state and the spin magnetic moment per molecule is 5.00μB/f.u. which comes mostly from the Sin3＋ ion only. By analysis of the band structure, the compound exhibits the direct band gap material and half-metallic ferromagnetic nature with 100% spin-up polarization, which implies potential applications of this new lanthanide compound in magneto-electronic and spintronic devices.
