金(I)催化丙二烯基化合物构建螺环[4,5]癸烷骨架的计算研究

采用B3LYP-D3(BJ)计算方法研究了金催化丙二烯基化合物合成螺环[4,5]癸烷骨架的反应机理。通过SMD模型在实验对应的CH3CN溶剂体系中进行单点能量计算得出更准确的能量。计算研究表明,该反应包括三个主要的步骤：烯丙基和乙烯基端基碳原子的分子内环加成、四元环重构为五元环的半频哪醇重排过程、消除反应释放催化剂并得到产物。结果显示第一步是反应的决速步骤,其活化自由能相对较低为70.18 kJ/mol,表明金催化的合成反应在室温条件下能够发生。     

Functionalization of ultradispersed diamond for DNA detection

Carbon nanotubes have been synthesized by catalytic chemical vapour deposition of acetylene diluted with argon using three different catalysts, namely, nickel formate, cobalt formate and ferrocene. The synthesis was carried out at 700°C in a quartz reactor for 30 minutes. Thermal analysis was carried out in order to determine the yield of the nanotube. It was found that the deposit contains 86% nanotube, with nickel-based catalyst, which was the maximum. The yield of nanotube was 71 times that of the nickel loading. The TEM images reveal helical type of nanotubes with iron catalyst while cobalt and nickel catalysts yielded straight nanotubes. This technique can be explored for the bulk production of carbon nanotube in an economic way.     

Contact improvement of carbon nanotubes via electroless nickel deposition

Individual multi-walled carbon nanotubes (CNTs) were deposited onto microelectrodes and embedded in nickel to achieve low-ohmic contact resistances. Electroless deposition of nickel onto gold/iron, palladium, and cobalt microelectrodes was used to form electrically stable bonds at the interfaces between the electrodes and CNTs. Resistance measurements showed that the contact resistances of the CNTs on gold/iron and palladium were significantly improved by nickel embedding, whereas no further improvement was found for the CNTs on cobalt. Electroless metal deposition is a parallel process providing stable electrical and mechanical contacts between CNTs and metallic microelectrodes. PACS 81.07.De     

爆轰合成碳包覆钴、镍磁性纳米颗粒的探索

 介绍了爆轰法合成碳包覆钴、镍纳米磁性颗粒研究的初步结果。以黑索今炸药为主体,加入钴、镍金属硝酸盐与有机碳源材料,在爆炸容器中氮气保护下用导爆管雷管引爆,成功地合成了碳包覆钴、镍纳米磁性颗粒。为了探求爆轰固体产物的形貌特征及性能,分别采用了TEM、XRD、VSM等测试手段对其进行表征。实验结果表明,爆轰产物中主要含有碳包覆纳米钴、纳米镍磁性颗粒,成球体或者椭球体,具有完好的核壳结构形貌。合成的碳包覆钴颗粒分布在30~50 nm之间,碳包覆的镍颗粒分布在25~60 nm之间,外层碳壳层主要由无定形碳和石墨构成。磁性测试表明,所得碳包金属钴、镍颗粒在室温下具有良好的软磁特性。     

STRUCTURE AND MORPHOLOGY OF CARBON NANOTUBES GROWN ON ZEOLITE-SUPPORTED CATALYSTS BY CHEMICAL VAPOR DEPOSITION

The zeolite-supported catalysts were prepared in nickel and cobalt nitrate aqueous solutions by ion exchange method. After reducing these substrates by hydrogen, we grew carbon nanotubes on them by chemical vapor deposition under different conditions. The results reveal that nickel/zeolite, cobalt/zeolite and nickel+cobalt/zeolite have different optimal conditions. When nickel+cobalt/zeolite was used as the catalyst, we can get straight carbon nanotubes. The Raman spectrum of the straight nanotubes shows they have fewer defects. We propose a growth mechanism for the growth of these nanotubes.     

火焰原子吸收光谱法测定钴-镍合金镀层中的钴和镍

利用原子吸收光谱法研究了在氨基磺酸钴-镍镀液中，赫尔槽试片上不同电流密度区合金镀层中钴、镍的含量。实验表明，该方法简便，快捷，结果准确，精密度高。相对标准偏差（RSD）为0.30%-0.62%，加标回收率为97.0%-104.0%。     

Removal of Congo red dye from aqueous solution with nickel-based metal-organic framework/graphene oxide composites prepared by ultrasonic wave-assisted ball milling

Metal-organic frameworks (MOFs) were successfully synthesized by ultrasonic wave-assisted ball milling. In the absence of organic solvent, the coupling effect of ultrasonic wave and mechanical force played an significant role in the synthesis of MOFs. Adsorption of Congo red (CR) was studied in view of adsorption kinetic, isotherm and thermodynamics. The adsorbent was carried out using X-ray diffraction (XRD), thermogravimetric analysis (TGA), N₂ adsorption-desorption isotherms, Raman spectroscopy and scanning electron microscope (SEM) methods. It was found that pseudo-second-order kinetic model and Freundlich adsorption isotherm matched well for the adsorption of CR onto nickel-based metal-organic framework/graphene oxide composites (Ni-MOF/GO). The results of the adsorption thermodynamics indicated that the adsorption process was a spontaneous and endothermic process. The adsorption capacity of graphene oxide/metal-organic frameworks (GO/MOFs) for CR reached 2489 mg/g, much higher than previous reports. It was demonstrated that an increase in the number of active metal sites can dramatically improve the adsorption capacity of dye. A suitable dry temperature is beneficial for the improvement of adsorption capacity for dye. In this paper, the adsorption results indicated that ultrasonic wave-assisted ball milling has a good prospect for synthesis of MOFs with excellent adsorption performance.     

Nickel–cobalt oxide/activated carbon composite electrodes for electrochemical capacitors

Nanostructured synthesis of nickel–cobalt oxide/activated carbon composite by adapting a co-precipitation protocol was revealed by transmission electron microscopy. X-ray diffraction analysis confirmed that nickel–cobalt oxide spinel phase was maintained in the pure and composite phases. Cyclic voltammetry, galvanostatic charge–discharge tests and ac impedance spectroscopy were employed to elucidate the electrochemical properties of the composite electrodes in 1.0 M KCl. The specific capacitance which was the sum of double-layer capacitance of the activated carbon and pseudocapacitance of the metal oxide increased with the composition of nickel–cobalt oxide before showing a decrement for heavily-loaded electrodes. Utilisation of nickel–cobalt oxide component in the composite with 50 wt. % loading displayed a capacitance value of ～59 F g^?1. The prepared composite electrodes exhibited good electrochemical stability.     

The wetting behaviour of silver on carbon, pure and carburized nickel, cobalt and molybdenum substrates

Properties such as thermal and electrical conductivity or the expansion behaviour of silver matrix composites with carbon based inclusions are strongly affected by the contact angle between carbon and silver. In order to promote wetting of carbon, insertion of metallic interlayers such as nickel, cobalt or molybdenum is a feasible approach. This paper presents contact angle measurements done with the sessile drop method on carbon substrates (glassy carbon, polycrystalline graphite) and on pure nickel, cobalt and molybdenum foils. The ability of these interlayer elements to lower the high contact angles of silver on glassy carbon (117°) and polycrystalline graphite (124°) under vacuum conditions was verified. Unlike nickel (30°) and cobalt (26°), molybdenum (107°) nevertheless was not wettable by liquid silver (at 1273 K) under vacuum conditions. ToF-SIMS was used to identify oxygen on the surface, causing higher contact angles than expected. After oxide reduction a contact angle of 18° on molybdenum was detected. Furthermore, the influence of carbon diffusion on the contact angle was investigated by gas phase carburization of the metal foils. ToF-SIMS and XRD identified dissolved carbon (Ni, Co) and carbide formation (Mo). However, only nickel and cobalt showed a slight decrease of the contact angle due to carbon uptake.     

催化剂对碳纳米管产率及质量的影响

本文研究了添加钴/二茂铁、镍/二茂铁、钴、镍/钴不同催化剂对高温热解法制备碳纳米管质量、产率等的影响。高分辨率透射电镜图象显示在800℃左右,镍/二茂铁、钴/二茂铁和钴催化条件下,有多壁碳纳米管生成,而用镍/钴作催化剂时,只有直径在0 5μm左右,长度十几个微米的非晶态棒状物生成。通过对生成碳纳米管的质量和产量进行比较,催化剂的催化活性满足二茂铁>钴>镍。简单分析了在碳源高温热解环境下不同金属催化剂的性能差异,并对不同催化条件下生成物的拉曼光谱进行了分析。     

生物油制氢中催化剂与吸收剂研究

本文利用固定床反应器考察了自制催化剂在生物油水溶性组分重整制氢反应中的表现以及耦合水蒸气预处理的CO2吸收剂对反应的影响。通过比较自制催化剂与商业催化剂Z417在重整反应中的催化性能,以及预处理吸收剂对重整反应的改进作用,结果表明：在反应温度为800℃,水油比为4．9的条件下,自制催化剂Ni／CeO2-ZrO2的氢产率...