新型钌系聚吡咯络合物的合成,结构和表征

采用电化学方法成功地合成了钌掺杂聚吡咯络合物（ＰＰＲＵＣ），ＰＰＲＵＣ是一种很稳定的非晶态络合物，合成掺杂聚吡咯络合物来改变催化剂的存在形态，使催化剂与反应物和产物很好地分离。用物理吸附仪对ＰＰＲＵＣ进行了比表面积和孔容等的测定，用红外和电子能谱对ＰＰＲＵＣ进行了表征，用元素分析仪测定了ＰＰＲＵＣ含Ｃ、Ｎ、Ｈ的比。根据测定结果和文献报道推断了ＰＰＲＵＣ的基本结构。     

Effect of Sm and Gd dopants on structural characteristics and ionic conductivity of ceria

Sm- and Gd-doped ceria electrolytes Ce_0.9Gd_0.1O_1.95 (GDC) and Ce_0.9Sm_0.1O_1.95 (SDC) were prepared by using the Pechini method. The microstructural and physical properties of the samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry/differential thermal analysis (TG/DTA) and Fourier Transform Infrared Spectroscopy (FTIR). The TG/DTA and XRD results indicated that a single-phase fluorite structure formed at a relatively low calcination temperature, 400 °C. The XRD patterns of the samples revealed that the crystallization of the SDC powders was superior than that of the GDC powders at 400 °C. The sintering behavior and ionic conductivity of the GDC and SDC pellets were also investigated. The sintering results showed that the SDC samples were found to have higher sinterability than the GDC samples at a relatively low sintering temperature, 1300 °C, a significantly lower temperature than 1650 °C, which is required for ceria solid electrolytes prepared by solid state techniques. The impedance spectroscopy results revealed that SDC has a higher ionic conductivity compared to GDC.     

Electrostatic Spray Deposition of Doped Ceria Films

Dense and thin electrolyte films are desirable for solid oxide fuel cells (SOFCs) because of their low gas leakage and low ohmic resistances. This work aims at the preparation of thin dense Gd‐doped ceria (CGO) electrolyte films using a cost‐effective deposition method in ambient atmosphere–electrostatic spray deposition (ESD). The deposition parameters such as deposition temperature, concentration and flow rate of precursor solution were changed systematically to examine their effects on film morphology and hence electrochemical performance. While the film morphology was examined by a scanning electron microscope, the electrochemical performance was revealed by measuring open circuit voltages (OCVs) of NiO‐CGO/CGO/Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3‐δ (BSCF) cells in 500–700 °C with humidified hydrogen as fuel and air as oxidant. The results show that a CGO film of 25 μm thick obtained at a deposition temperature of 400 °C, a precursor solution flow rate of 6 ml h^–1 and a precursor concentration of 0.3 M was dense with very few isolated pores and the OCV of the associated cell was 0.915 V at 500 °C. This implies that the CGO film has negligible gas leakage and ESD is a promising method for preparing thin dense electrolyte films for SOFCs.     

Infrared spectroscopic ellipsometry of Ge-doped SbTe alloys

We grew Ge-SbTe films on glass substrates using RF sputtering deposition. We measured the dielectric function of the Ge-doped SbTe thin films in the infrared and visible spectral region. By applying linear extrapolation to the absorption coefficient, we obtained accurate band gap energy values, which decreased with increasing Te composition. Using the Drude model, we estimated their resistivity and mean scattering time. Compared to the Hall effect parameters of carrier concentration and mobility, we estimated the effective mass of holes for the Ge-SbTe thin films.     

Addition effects of erbia-stabilized bismuth oxide on ceria-based carbonate composite electrolytes for intermediate temperature-−solid oxide fuel cells

Highly conductive Er_0.2Bi_0.8O_1.5 (ESB) and rare-earth doped ceria solid oxide electrolytes (SOEs) at intermediate temperature (IT) continue to suffer disadvantages in terms of thermodynamic instability and significant electronic conduction, respectively, at low oxygen partial pressure for solid oxide fuel cell (SOFC) operations. It is therefore necessary to improve the low-temperature ionic conductivity in order to enhance the electrolytic domain of these materials and thereby mitigate cell efficiency dissipation by electronic conduction. In this work, an advanced multiphase carbonate composite material based on ceria has been developed to overcome this IT-SOE challenge. This advanced electrolyte is comprise of nanostructured neodymium-doped ceria (NDC) and 38 wt% (Li–0.5Na)₂CO₃ carbonate with a small amount of ESB phase. The addition of 2 wt% ESB in ceria-based materials decreases the grain boundary resistance of the SOEs in the IT range. Further, a small amount of highly conducting ESB phase in the NDC/[(Li–0.5Na)₂CO₃] composite electrolyte increases the overall conductivity of the composite SOEs. The NDC electrolyte containing 38 wt% carbonate shows the highest conductivity of 0.104 Scm⁻¹ at 600 °C, while the conductivity is increased to 0.165 Scm⁻¹ by the addition of 2 wt% ESB. In addition, the activation energy of the multiphase composite electrolytes (0.52 eV) is lower than that of the NDC/carbonates (0.65 eV) in the IT range. This is attributed to the effect of the physical properties of the NDC sample, induced by the light ESB doping, on the ionic conductivity, and this effect is closely associated with the grain boundary property. Furthermore, the interfacial effects of the multiphase materials also contribute to the improved conductivity of this advanced composite electrolyte.     

钙钛矿型YAl（1-x）CrxO3红色陶瓷颜料的研究

本研究通过固相反应法,以氧化钇和氢氧化铝为主要原料,掺杂少量氧化铬,在1450-1600℃和中性气氛的条件下,合成了钙钛矿型YAl（1-x）CrxO3红色陶瓷颜料。通过XRD和SEM分析,对颜料的性能和结构行了初步探讨。试验发现掺杂少量其它稀土元素会使得颜料的色调发生改变,对呈色有利。指出多组分掺杂技术是开发新型环保陶瓷颜料的研究方向之一。     

Visible-light-driven TiO2 catalysts doped with low-concentration nitrogen species

Visible-light-driven nitrogen-doped TiO₂ was synthesized using a novel nitrogen-ion donor of hydrazine hydrate. Low-concentration (0.2 at%) nitrogen species and Ti³⁺ were detected in the TiO₂-based photocatalyst by X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) spectroscopy. The trace amount of Ti–N would contribute to the minor band-gap narrowing of about 0.02 eV. Those nitrogen-containing species, especially the NO₂²⁻ species, form surface states, which make the catalysts possible to degrade 4-chlorophenol (4-CP) under visible irradiation (λ>400 nm). Moreover, Ti³⁺ species induce oxygen vacancy states between the valence and the conduction bands, which would also contribute to the visible response. The photocatalytic activity of the nitrogen-doped TiO₂ catalyst was thought to be the synergistic effect of nitrogen and Ti³⁺ species. The catalysts showed higher photocatalytic activity for degradation of 4-CP than pure TiO₂ under not only visible but also UV irradiation. The visible response and the higher UV activity of the nitrogen-doped TiO₂ make it possible to utilize solar energy efficiently to execute photocatalysis processes.     

Enhancing the photocatalytic activity of Cd–ZnS(EN)0.5 hybrid sheets for the H2 production

Ultrathin sheets of ZnS(EN)_0.5 modified with Cd²⁺ ions were prepared by chemical precipitation in a mixture of butanol-ethylenediamine-water solution. The Cd²⁺ content was varied from 0.1 to 0.6 M ratio and its influence in the physicochemical properties of the formed Cd–ZnS(EN)_0.5 hybrid compounds was investigated by diverse techniques: X-ray Diffraction, Thermogravimetric, Textural analysis, Infrared, Diffuse Reflectance and X-ray Photoelectron Spectroscopies, Scanning Electron and High-Resolution Transmission Electron Microscopy. The photocatalytic H₂ production of the unmodified ZnS(EN)_0.5 hybrid was tested using hydrazine, ethanol, and methanol as sacrificial electron donors reagents (SEDr), presenting an H₂ evolution rate of 2.4, 21 and 23 μmolh⁻¹, respectively. The results showed that the orthorhombic ZnS(EN)_0.5 structure was stable but suffer exfoliation of the lamellar structure during the photocatalytic cycles in methanol-water solution under UV irradiation. The doped Cd–ZnS(EN)_0.5 hybrid presented an enhanced H₂ production rate (32 μmolh⁻¹) for low Cd²⁺ doping, showing only minor exfoliation of the lamellar structure and stability of the orthorhombic structure, preserving the high photoactivity after 6 cycles of irradiation.     

新型杂多酸盐异构体聚苯胺掺杂材料的电化学分析

首次以铁为取代元素的杂多酸盐异构在有酸的情况下采用固相法与苯胺进行掺杂,利用极谱伏安法对产物的电化学活性及氧化还原性质进行分析.     

Highly conducting doped poly-Si deposited by hot wire CVD and its applicability as gate material for CMOS devices

Highly conducting p- and n-type poly-Si:H films were deposited by hot wire chemical vapor deposition (HWCVD) using SiH₄+H₂+B₂H₆ and SiH₄+H₂+PH₃ gas mixtures, respectively. Conductivity of 1.2×10² (Ω cm)⁻¹ for the p-type films and 2.25×10² (Ω cm)⁻¹ for the n-type films was obtained. These are the highest values obtained so far by this technique. The increase in conductivity with substrate temperature (T_s) is attributed to the increase in grain size as reflected in the atomic force microscopy results. Interestingly conductivity of n-type films is higher than the p-type films deposited at the same T_s. To test the applicability of these films as gate contact Al/poly-Si/SiO₂/Si capacitor structures with oxide thickness of 4 nm were fabricated on n-type c-Si wafers. Sputter etching of the poly-Si was optimized in order to fabricate the devices. The performance of the HWCVD poly-Si as gate material was monitored using C–V measurements on a MOS test device at different frequencies. The results reveal that as deposited poly-Si without annealing shows low series resistance.