表面氧化外延制备钇系涂层导体隔离层

采用表面氧化外延(SOE)方法, 在金属基底上研制NiO隔离层. 通过研究温度、时间等工艺参数对形成立方织构NiO的影响, 摸索出一套可获得单一、尖锐的立方织构NiO, 重复性好, 适合于长带发展的工艺技术. 同时研究了金属基带的表面状态、织构取向对NiO(100)表面的影响. X射线极图观测可直观地看到单一的立方织构, φ扫描检测其半高宽(FWHM)均为7.5°. 扫描电镜观察NiO(100)膜层表面形貌, 无裂纹且较为致密.     

利用环糊精包结的醋酸镍制备NiO纳米粒子

NiO nanoparticles are prepared via thermal decomposition of nickel acetate coated by β-CD, and Characterized by using X-ray diffraction (XRD), transmission electron microscopy (TEM). Thermo-gravimetric (TG) analysis and electro spray mass spectrum (ESI-MS) are performed to investigate the thermal decomposition process and the possible formation mechanism of obtaining good morphology NiO nanoparticles by this method. Further, different CDs are used to prepare the precursors of inclusion complexes, and there are little affect of CD′s type on the NiO nanoparticles.     

熔盐法合成NiO纳米微晶

纳米科技的基础是纳米结构材料的合成．它是纳米科技在分散与包覆、高比表面材料、功能纳米器件、强化材料等方面实现突破的起点。纳米颗粒（1-100nm）本身具有宏观量子隧道效应、量子尺寸效应、表面效应许多独特的性能．其制备研究日益得到广泛关注和重视．     

Preparation and characterization of CuO/SiO2 and NiO/SiO2 with bimodal pore structure by sol-gel method

CuO/SiO₂ and NiO/SiO₂ with bimodal pore structure were prepared by sol-gel reactions of Tetra-methoxysilane (TMOS) and the respective metal nitrate in the presence of poly (ethylene oxide) (PEO) with an average molecular weight of 10 000 and the catalyst of acetic acid. In this process, the interconnected macroporous morphology was formed when transitional structures of spinodal decomposition were frozen by the sol-gel transition of silica. The addition of copper and nickel into the silica-PEO system had a negligible effect on the morphology formation. In gel formation, it was found that NiO crystalline sizes in the samples increased with decreasing Si/Ni molar ratio. It was considered that PEO interacted with both silica and nickel cations. In the CuO/SiO₂ with the presence of PEO_, CuO crystalline sizes were larger than those of NiO/SiO_2. It was considered that there was no obvious interaction between the Cu cation and PEO, most of the copper ions in wet silica gel were present in the outer solution. They easily aggregated as copper salts in the drying process of wet gel and decomposed into CuO particles in heating. While in the CuO/SiO₂ with the absence of PEO, the Cu was selectively entrapped as small particles in the gel skeleton due to the interaction between Cu aqua complex and silica gel network.     

Mesoscale assembly of NiO nanosheets into spheres

NiO solid/hollow spheres with diameters about 100 nm have been successfully synthesized through thermal decomposition of nickel acetate in ethylene glycol at 200 °C. These spheres are composed of nanosheets about 3-5 nm thick. Introducing poly(vinyl pyrrolidone) (PVP) surfactant to reaction system can effectively control the products’ morphology. By adjusting the quantity of PVP, we accomplish surface areas-tunable NiO assembled spheres from ∼70 to ∼200 m² g⁻¹. Electrochemical tests show that NiO hollow spheres deliver a large discharge capacity of 823 mA h g⁻¹. Furthermore, these hollow spheres also display a slow capacity-fading rate. A series of contrastive experiments demonstrate that the surface area of NiO assembled spheres has a noticeable influence on their discharge capacity.     

Comparative Actions of NiO and TiO<Subscript>2</Subscript> Catalysts on the Destruction of Phenol and its Derivatives in a Dielectric Barrier Discharge

This study examined processes of decomposing phenol and its derivatives (resorcin, pyrocatechol and hydroquinone) in aqueous solutions under the action of an atmospheric pressure oxygen dielectric barrier discharge in the presence or absence of catalysts in the plasma zone. Two types of catalysts were tested, NiO and TiO₂. It was found that both materials exhibited catalytic properties. The action of NiO accelerated the step of phenol destruction while the action of TiO₂ catalyst resulted in a more preferable composition of decomposition products and provided a higher degree of carboxylic acid conversion into carbon dioxide than the NiO catalyst.     

Mechanism of low temperature decomposition of NiO single crystals

The decomposition of NiO single crystal was investigated under dissociative conditions in the temperature interval between 330 and 850 °C in the absence of reducing gas species. An unusually fast and constant decomposition rate was measured at the lowest temperatures, coupled with an unusual largely porous microstructure of the metallic product layer. This anomalous high reaction rate was interpreted on the basis of a decomposition mechanism implying the dissociative vaporization of the oxide followed by the condensation of the metal. The proposed mechanism is supported by the microstructure of the product and of the reacting interface. The complex dependence of reaction rate from temperature was shown to be related to a collapse of the porous product to form a compact metal layer at higher temperatures due to sintering.     

前驱物对NiO/SiO_2气凝胶催化剂性能的影响

分别用硝酸镍、醋酸镍和氯化镍为活性组分前驱物,正硅酸乙酯为硅源,采用 溶胶凝胶超临界流体干燥法制备了N-SiO_2,Ac-SiO_2和C-SiO_2催化剂,经TEM, TPR,XRD,IR等物性结构表征及催化加氢活性评价结果表明：前驱物对由溶胶凝胶 法制备催化剂中氧化镍的分散性,晶粒大小及与载体的相互作用都有明显的影响, N-SiO_2催化剂有Ni-O-Si键形成,NiO呈簇团结构,粒径最小,分散性最好,但加 氢活性最低;Ac-SiO_2和C-SiO_2催化剂中氧化镍呈微晶态,与载体相互作用较弱 。在三种催化剂中,NiO与载体相互作用强弱顺序为：N-SiO_2 > Ac-SiO_2 > C- SiO_2,但加氢活性大小顺序相反为：C-SiO_2 > Ac-SiO_2 > N-SiO_2;C-SiO_2催 化剂加氢活性和丁二酸酐的选择性均在99%以上。     

熔融碳酸盐燃料电池ZnO/NiO阴极稳定性及电化学性能研究

以ZnO作添加物,采用流延成型法制备了ZnO/Ni复合阴极,研究其微观形貌和相组成,并应用交流阻抗谱研究了ZnO/NiO复合阴极在(Li0.62K0.38)2CO3低共熔盐中的稳定性和电化学性能.结果表明,ZnO/Ni复合阴极和Ni阴极具有基本相近的表面形貌、空隙率和孔径尺寸.ZnO的添加能显著降低NiO在熔盐中的溶解度,其中,2mol%ZnO/NiO复合阴极的NiO溶解度比纯NiO阴极的约低1个数量级,并具有较低的电荷传递电阻(接近于纯NiO值),可望成为MCFC一种很有前景的阴极材料.     

A Study on Production of Carbon Nanotubes by CH_4 Decomposition over LaNiO_3,La_4Ni_3O_(10),La_3Ni_2O_7 and La_2NiO_4

IntroductionIn the present study, by employing the citric acid complex method1, we prepared a series of perovskite-type oxides, viz. LaNiO3, La4Ni3O10, La3Ni2O7 and La2NiO4 for the growth of CNTs. After H2 reduction, the catalysts turn into La2O3 and active component Ni0 of various sizes. By means of CH4 decomposition over the reduced catalysts, high quality CNTs with dissimilar diameters can be generated in mass amount. In this paper, we attempt to make a comparison on the structure…