排序方式: 共有13条查询结果,搜索用时 15 毫秒
1.
Ch. V. Subba Reddy Y. Y. Qi W. Jin Q. Y. Zhu Z. R. Deng W. Chen Sun-il Mho 《Journal of Solid State Electrochemistry》2007,11(9):1239-1243
Molybdenum trioxide (MoO3) xerogel films modified with poly(vinyl alcohol)+poly(vinyl pyrrolidone) (PVP+PVA) polyblends were obtained by ion-exchange
method with sol-gel technique. Investigations were conducted using X-ray “diffractometry”, Fourier transform infrared spectroscopy,
and cyclic voltammetry. The results show that the H atoms in polyblend are H-bonded with the O atoms in the Mo=O bonds of
MoO3 xerogel, which effectively shield the electrostatic interaction between MoO3 interlayer and Li+ ions when MoO3 xerogel is modified by the intercalation of (PVP+PVA). The reversibility of the insertion/extraction of Li+ ions is greatly improved by the modification with polyblend of MoO3 nanocomposite films. MoO3 and (PVP+PVA)
x
MoO3 (x = 0, 0.5) nanobelts were obtained by a simple hydrothermal process from MoO3 sol. The electrochemical cells with configuration Li/(LiPF6+EC+DMC)/MoO3 modified by (PVP+PVA) were fabricated and their discharge profiles studied. 相似文献
2.
C.V. Subba Reddy Z.R. Deng Q.Y. Zhu Y. Dai J. Zhou W. Chen S.-I. Mho 《Applied Physics A: Materials Science & Processing》2007,89(4):995-999
Molybdenum trioxide (MoO3) and PPyxMoO3 (x=0.5 and 1) nanobelts were obtained by the simple hydrothermal process from MoO3 sol. The morphology and structure of the samples were characterized using X-ray diffractometry (XRD), Fourier transformation
infrared spectroscopy (FTIR), Raman spectra, SEM and AFM. The results show that the H atoms in polypyrrole are H-bonded with
the O atoms in the Mo=O bonds of MoO3 nanobelts. Using the electrolyte, we fabricated electrochemical cells with a configuration of Li/(LiPF6+EC+DMC)/(MoO3+acetyleneblack+PTFE) and studied discharge profiles.
PACS 81.07.BC; 81.05.Je; 82.47.Aa; 82.45.Fk; 82.45.Gj 相似文献
3.
Efficient visible photoluminescence of porous Si is observed on highly porous material, which is currently attributed to quantum confinement effects of the carrier in nanometric sized silicon wires or dots. In this work, the growth of porous silicon layer has been monitored using electrochemical impedance technique. 相似文献
4.
Mindong Chen Fei Teng Guiqing Li Huaxia Shi Jun Wang Mengjiao Xu Xuequn Ji Tianyun Lu Yingjie Lv Sun-il Mho 《Ionics》2012,18(6):541-547
In this work, the LiFePO4 samples are synthesized in ethylene glycol/water (EG/W) and aqueous solution, respectively. The samples are characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, electron diffraction, and nitrogen adsorption isotherms. The results show that the reaction medium and the surfactant molecules have the significant influences on the particle morphology. In the presence of dodecylbenzenesulfonic acid sodium, the highly uniform LiFePO4 hierarchical nanostructures are obtained in EG/W, which consist of the nanoplates. Nevertheless, the irregular LiFePO4 microparticles are obtained in aqueous solution. Furthermore, the electrochemical properties of the samples are mainly investigated. The hierarchical LiFePO4 sample exhibits a higher rate capability and an improved cyclability than the aggregated irregular microparticles, which have been ascribed to the highly uniform hierarchical nanostructures. 相似文献
5.
The voltammetric responses observed for carbohydrates and polyalcohols at 0.60 V in 0.10 M NaOH are significantly larger at preanodized CuMn (95:5) electrodes as compared to preanodized pure Cu electrodes. Apparent values for the number of electrons transferred (napp) and the corresponding values of heterogeneous rate constants (kapp) are estimated for selected reactants from the slopes and intercepts, respectively, of Koutecký–Levich plots of background-corrected voltammetric currents obtained at CuMn and Cu rotated disk electrodes (RDEs). Values of napp (and kapp) for sorbitol and glucose are 11.8 (9.2×10−3 cm s−1) and 11.7 (8.0×10−3 cm s−1), respectively, at a CuMn RDE. These are compared to the values 10.4 (1.8×10−3 cm s−1) and 9.6 (2.0×10−3 cm s−1) for sorbitol and glucose, respectively, at a Cu RDE. The larger sensitivities observed at the CuMn RDE in comparison to the Cu RDE are concluded to be the beneficial result of larger kapp values at the alloy electrode. Furthermore, the larger kapp values are speculated to result from enhanced preadsorption of the reactant species at Mn(IV) sites in the preanodized CuMn surface. In flow-injection measurements, the peak signals obtained for successive injections of glucose using a CuMn electrode (0.60 V vs. SCE) were quite stable with a standard deviation of 1.5%. However, large day-to-day variations (±15%) observed in the average peak signals are attributed to the temperature sensitivities of the kapp value and the diffusion coefficient for glucose. 相似文献
6.
EDLC characteristics with high specific capacitance of the CNT electrodes grown on nanoporous alumina templates 总被引:2,自引:0,他引:2
Well-ordered nanoporous alumina templates were fabricated by two-step anodization method by applying a constant voltage of 40 V in oxalic acid solution or of 25 V in sulfuric acid solution. The cylindrical pore diameter and pore density of the templates utilized for the carbon nanotube (CNT) growth were 86 ± 5 nm and 1.2 × 1010 cm−2 in oxalic acid solution and 53 ± 1 nm and 3.1 × 1010 cm−2 in sulfuric acid solution, respectively. The CNTs with uniform diameter of 50 ± 10 nm (oxalic acid) and 44 ± 2 nm (sulfuric acid) were grown on the porous alumina template as electrode materials for the electrochemical double layer capacitor (EDLC). The EDLC characteristics were examined by measuring the capacitances from cyclic voltammograms and the charge–discharge curves. The specific capacitances of the CNT electrodes are 30 ± 1 F/g (Φ = 50 ± 10 nm) and 121 ± 5 F/g (Φ = 44 ± 2 nm). The high specific capacitance of the CNT electrode was achieved by using nanoporous alumina templates with the high pore density and the small and uniform pore diameter. 相似文献
7.
The photoluminescence and low-voltage cathodoluminescence characteristics of BaTi4O9:Pr3+ were investigated. The excitation band of intervalence charge transfer (IVCT) of BaTi4O9:Pr3+ emerged distinctly at 330 nm. The resultant emissions appeared at 606-643 nm corresponding to the 1D2→3H4 transition. In BaTi4O9:Pr3+, the emission of 3P0→3H4 transition at 490 nm was not observed. The results were in a pure red color emission. 相似文献
8.
Ch.V. Subba Reddy G.P. Wu C.X. Zhao W. Jin Q.Y. Zhu W. Chen Sun-il Mho 《Current Applied Physics》2007,7(6):655-661
Composite polymer electrolyte films consisting of polyethylene oxide (PEO), LiAsF6 and mesoporous silica (MCM-41) with fixed PEO/LiAsF6 = 90/10 but different weight percent ratios of MCM-41 were prepared using the solution casting method. The polymer electrolyte films were characterized using XRD, DSC, SEM and electrical impedance spectroscopy. In corporation of MCM-41 in a (PEO + LiAsF6) polymer electrolyte facilitates salt dissociation, enhances ion conductivity, and improves miscibility between organic and inorganic moieties. The scanning electron microscopy (SEM) photographs indicates the electrolytes are miscible and homogeneous up to 10 wt.% of MCM-41, and an optimized conductivity is found at this composition (10 wt.%). However, at higher weight ratios (>10 wt.%), the Li/MCM-41-rich domain developed, and the conductivity decreased with increasing mesoporous material. The electrochemical performance of fabricated electrochemical cells of configuration Li/(PEO + LiAsF6 + MCM-41)/(MoO3 + C + PTFE) were investigated. 相似文献
9.
Vacuum ultraviolet (VUV) excitation and photoluminescence (PL) characteristics of Eu3+ ion doped borate phosphors; BaZr(BO3)2:Eu3+ and SrAl2B2O7:Eu3+ are studied. The excitation spectra show strong absorption in the VUV region with the absorption band edge at ca. 200 nm for BaZr(BO3)2:Eu3+ and 183 nm for SrAl2B2O7:Eu3+, respectively, which ensures the efficient absorption of the Xe plasma emission lines. In BaZr(BO3)2:Eu3+, the charge transfer band of Eu3+ does not appear strongly in the excitation spectrum, which can be enhanced by co-doping Al3+ ion into the BaZr(BO3)2 lattices. The luminescence intensity of BaZr(BO3)2:Eu3+ is also increased by Al3+ incorporation into the lattices. The PL spectra show the strongest emission at 615 nm corresponding to the electric dipole 5D0→7F2 transition of Eu3+ in both BaZr(BO3)2 and SrAl2B2O7, similar to that in YAl3(BO3)4, which results in a good color purity for display applications. 相似文献
10.
Fabrication of quantum dot array (QDA) is attractive for applications in electronic and optoelectronic devices. The CdTe QDAs have potential applications in optoelectronic devices of visible range. One of the major challenges in fabricating QDAs is the uniformity and reproducibility in size and spatial distribution. The uniformity and reproducibility of QDs can be improved by using the nanoporous alumina mask. The geometry of porous alumina is schematically represented as a close-packed array of columnar hexagonal cells, each containing a central pore normal to the substrate. The well-ordered nanoporous alumina masks were able to obtain by two-step anodizing processes from aluminum in oxalic acid solutions at low temperature. The pore size, thickness, and density of nanoporous alumina mask can be controlled with the anodization voltage, time, and electrolyte. The CdTe QDAs on the GaAs substrate was grown by molecular beam epitaxy method using the porous alumina masks. The temperature of substrate and source (Cd, Te) was an important factor for the growth of CdTe QDs on GaAs substrate. The CdTe QDAs of 80 nm dot size was fabricated; using the porous alumina masks (300 nm thickness) of pore diameter (80 nm) and density (1010 /cm2). 相似文献