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油酸钠/Fe纳米粒子的制备及其脱氯性能研究 总被引:3,自引:0,他引:3
采用油酸钠作为包覆剂,在液相体系中制备油酸钠/Fe纳米复合粒子,并用TEM、XRD、FT-IR、DSC-TGA对所制得的纳米复合粒子进行结构表征.结果表明,油酸钠/Fe纳米复合粒子呈核壳结构,粒度分布窄,其粒径在90nm左右;T-IR和DSC-TGA分析证明纳米铁与油酸钠之间发生了化学键合,具有空气稳定性,而且憎水亲油;将油酸钠/Fe纳米复合粒子与三氯乙烯(TCE)模拟水样反应,发现油酸钠/Fe纳米复合粒子能够与水相中的三氯乙烯(TCE)有良好的接触性,其脱氯效果优于未修饰的纳米铁粒子. 相似文献
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采用盐助溶液燃烧法,以硝酸铜和硝酸钴为原料,尿素为燃烧剂,KCl为反应惰性盐制备尖晶石型纳米钴酸铜。采用XRD、FT-IR、Raman和TEM等测试手段对产物进行了表征。结果表明,制得的纳米粒子具有较完美的晶体结构,分散性较好,粒径约为50nm。利用热分析法考察了纳米钴酸铜对高氯酸铵热分解的催化作用。结果显示纳米钴酸铜具有较高的催化活性,添加2%的纳米钴酸铜热分解温度降低136℃,催化效果优于单一组分的纳米金属氧化物。 相似文献
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氢电弧等离子体法制备碳包铁纳米粒子 总被引:5,自引:0,他引:5
采用氢电弧等离子体法制备了碳包铁纳米粒子,通过X射线衍射仪(XRD)、透射电镜(TEM)、扫描电镜(SEM)、X射线能谱仪(EDS)、热重-差热分析仪(TG-DSC)等分析手段对粒子的成分、形貌,相结构,热性能等进行了表征.结果表明,制备的粒子中含有α-Fe、Fe3 C、无定形碳和石墨,没有铁的氧化物相出现.铁粒子外碳层的厚度为5~15nm,碳包铁纳米粒子的熔点为1360℃,碳层的存在增强了纳米粒子的抗酸蚀能力. 相似文献
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利用油酸对纳米二氧化钛进行有机表面修饰, 将修饰后的纳米粉体超声分散到变压器油中制备纳米二氧化钛改性变压器油, 研究了表面修饰对纳米二氧化钛在变压器油中分散性的影响. 采用X射线粉末衍射(XRD)、透射电镜(TEM)、红外光谱(FT-IR)和热分析(TG)对纳米二氧化钛的形貌、结构和表面修饰状态进行表征。结果表明, 油酸与纳米二氧化钛表面以双齿桥连配位方式键合, 在纳米二氧化钛表面形成了良好的修饰层。随着修饰剂的增加, 尽管油酸在纳米二氧化钛表面的配位方式没有发生改变, 但化学包覆量明显增加, 表面油酸分子的排列也更为紧密, 从而使纳米二氧化钛粒子在变压器油中的分散性和稳定性显著提高。当钛盐与油酸摩尔比为1:24时, 二氧化钛纳米粒子可以稳定分散在变压器油中, 室温静置30 d后仍保持澄清透明。 相似文献
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采用共沉淀法制备BiNbO4纳米棒。利用X射线粉末衍射仪(XRD)、透射电镜(TEM)、紫外-可见漫反射光谱(UV-Vis DRS)和热重分析(TG/DTA)对其结构、形貌和性质进行表征,并通过紫外-可见分光光度计分析BiNbO4纳米棒光降解罗丹明B来研究其光催化活性。结果表明以五氧化二铌和五水硝酸铋为原料制备得到正交相结构的BiNbO4纳米棒;BiN-bO4纳米棒具有较高的光催化活性,在紫外光下,pH值=3.05,催化剂用量为2g/L时能够有效地降解罗丹明B,降解率受到光源、催化剂浓度和溶液pH值的影响较大。 相似文献
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纳米MgO/SnO2复合粉体的制备及性能研究 总被引:1,自引:0,他引:1
采用共沉淀法制备了MgO/SnO2纳米复合粉体.用热重分析(TG)、X射线衍射仪(XRD)、透射电镜(TEM)和能谱(EDS)对样品的物相、形貌、粒径和组成进行了表征.并用DSC考察了纳米MgO/SnO2对RDX热分解的催化作用.结果表明 400℃煅烧样品的平均粒径约为3nm, MgO的掺杂可提高纳米SnO2粒子的热稳定性和对RDX热分解的催化作用, 它使RDX的分解峰温降低了8.5℃, 分解热增加了518J·g-1(约50%). 相似文献
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M. Alagiri C. Muthamizhchelvan Sharifah Bee Abdul Hamid 《Journal of Materials Science: Materials in Electronics》2013,24(11):4157-4160
The superparamagnetic (SPM) cobalt nanoparticles with an average size of 2 nm have been prepared through a solvothermal process in the presence of triethanolamine. The synthesized nanoparticles are characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy, and superconducting quantum interference device magnetometer. X-ray diffraction analysis confirms the face centered cubic phase of as-prepared cobalt nanoparticles. Transmission electron microscopy was employed to study the morphology of the as-prepared product, which exhibit spherical-like shape with size around 2 nm. The high resolution transmission electron microscopy image of cobalt nanoparticles shows the lattice spacing value of 0.204 nm. This is well matched with the (111) lattice spacing of fcc Co. XPS revealed the prepared product is pure cobalt. The blocking temperature of 17 K was obtained and confirmed by field-cooled and zero-field-cooled plots. The hysteresis loop revealed the synthesized nanoparticles have SPM character at room temperature. 相似文献
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Pure and Co-doped CdSe nanoparticles have been synthesized by hydrothermal technique. The synthesized nanoparticles have been characterized using X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV–Visible), photoluminescence spectroscopy (PL), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and superconducting quantum interference device (SQUID), at room temperature. From XRD analysis, pure and cobalt-doped CdSe nanoparticles have been found to be polycrystalline in nature and possess zinc blende phase having cubic structure. In addition to this, some peaks related to secondary phase or impurities such as cobalt diselenide (CoSe2) have also been observed. The calculated average crystallite size of the nanoparticles lies in the range, 3–21 nm, which is consistent with the results obtained from TEM analysis. The decrease in average crystallite size and blue shift in the band gap has been observed with Co-doping into the host CdSe nanoparticles. The magnetic analysis shows the ferromagnetic behaviour up to 10% of Co-doping concentration. The increase of Co content beyond 10% doping concentration leads to antiferromagnetic interactions between the Co ions, which suppress the ferromagnetism. 相似文献
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水热介质pH值对纳米(Ce)ZrO_2晶粒制备的影响 总被引:1,自引:0,他引:1
《中国粉体技术》2000,6(Z1):284-286
用水热法制得纳米 (Ce)ZrO2 粉体 ,其晶粒粒度为 3~ 7nm ,而且为单一分散。用XRD、TEM分析了水热媒介pH值对粒度、m相含量、晶粒形貌的影响关系。结果表明 :水热煤介 pH值增大 ,ZrO2 晶粒也增大 ;pH值减小至酸性时 ,ZrO2 晶粒中出现部分m相 ,且晶粒易团聚 相似文献
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A green strategy for the facile preparation and effective stabilization of Pd nanoparticles has been developed by using D-glucose as the reducing and stabilizing agents. The UV/vis absorption spectroscopy, transmission electron microscopy (TEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and zeta potential measurements were used to characterize the as-prepared Pd nanoparticles. It was found that the D-glucose concentration and pH value had an important effect on the size distribution and stability of the nanoparticles. Further, the Pd nanoparticles exhibited good catalytic properties in the degradation of azo dyes. 相似文献
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Shankar B. Dalavi 《Particulate Science and Technology》2015,33(1):97-101
Nanomaterials based on Co and Ni are technologically important because of their potential technological applications in recording media, catalysis, drug delivery systems, and so on. Recent research interests lie on the synthesis of Co and Ni nanomaterials by chemical synthesis, characterizations and studying for their interesting magnetic properties. In this investigation, we have focused on the synthesis of cobalt and nickel nanoparticles (NPs) in aqueous medium at ambient conditions by sodium borohydride reduction route. We have successfully stabilized the nanospheres comprising of Co and Ni by using polyethylene glycol (PEG) as capping agent. The Co and Ni nanomaterials were exhaustively characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and magnetic measurements. The phase purity and crystallite sizes were ascertained by using powder XRD method. Co and Ni NPs crystallize in face centered cubic (fcc) structure with lattice parameters (a) equal to 3.54 Å and 3.52 Å, respectively. The XRD lines were broad and indicate the fine particle nature of the materials. The estimated crystallite sizes were found to be 42 and 29 nm for Co and Ni, respectively. SEM micrograph studies show the particle sizes to be 80 and 70 nm, whereas TEM studies confirm the sizes to be 47 and 65 nm for Co and Ni, respectively. The electron micrograph studies indicate the appearance of agglomerates of the nanoparticles consisting of several crystallites. The specific magnetization versus field characteristics of Co and Ni nanoparticles shows the signature of the size and surface effects. The values of saturation magnetizations are found to be 122 and 47 emu/g, whereas the coercivity values are 111 Oe and 84 Oe for Co and Ni, respectively. In summary, we have synthesized high moment Co and Ni nanostructured materials with reduced coercivities, which may be useful for soft magnetic applications. 相似文献
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Azam Sobhani Masoud Salavati-Niasari 《Journal of Materials Science: Materials in Electronics》2016,27(4):3271-3280
In this article, the synthesis and characterization of Co2P/Co nanocomposites are reported. Three kinds of precursors are studied: bis(salicylidene)cobalt(II) [Co(sal)2], bis(salicylate)cobalt(II) [Co(Hsal)2] and cobalt oxalate [Co(O4C2)·4H2O]. The cobalt(II) acetate tetrahydrate Co(CH3COO)2·4H2O is used as reference. The nanocomposites are prepared by thermal decomposition method using triphenylphosphine as a surfactant solvent and phosphorus precursor. A possible mechanism of the formation of the nanocomposites is put forward to explain the experimental observations. This is the first time that Co2P/Co nanocomposites are synthesized. To study the crystalline structure, composition, size, morphology and magnetic property of the products, characterization techniques including XRD, SEM, TEM, FT-IR and VSM are employed. 相似文献
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《Materials Research Bulletin》2006,41(11):2041-2048
Size-controlled synthesis of phase pure Cu nanoparticles was carried out by using copper sulfate pentahydrate as a precursor, ascorbic acid as a reductant, Tweens and sodium dodecyl sulfate (SDS) as modifiers in an aqueous solution at 80 °C. The as-prepared Cu nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and Fourier transform infrared (FT-IR). The stabilizing effects of SDS and Tweens on the Cu nanoparticles should be through the coordination between Cu nanoparticles and the respective sulfate group and oxygen-containing bond. The synergic effect of the composite SDS and Tweens on Cu nanoparticles was different from those arising from the individuals. 相似文献
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A. Lähde R.J. Chimentão T. Karhunen M.G. Álvarez J. Llorca F. Medina J. Jokiniemi L.B. Modesto-López 《Advanced Powder Technology》2017,28(12):3296-3306
The catalytic properties of Co-Al spinel nanoparticles prepared by liquid-feed flame spray pyrolysis (L-F FSP) were investigated in the glycerol conversion in gas phase in an atmosphere of hydrogen. Reduction at 1123?K of the as-synthesized spinel nanoparticles induced the formation a new phase containing metallic cobalt species. Although, the reducibility of cobalt oxides is greatly decreased due to interaction with aluminium species, this strong interaction may prevent the aggregation of Co particles under the harsh reduction conditions. X-ray photoelectron spectroscopy (XPS) of the reduced spinel nanoparticles at 1123?K revealed that the Co/Al atomic ratio has decreased to Co/Al?=?0.11, which may indicate a redistribution of the aluminum and cobalt species at the surface of the sample submitted to the reduction in a flow of hydrogen at 1123?K. X-ray diffraction (XRD) and high resolution electron microscopy (HRTEM) also reinforced the formation of metallic cobalt species after reduction of cobalt from the spinel nanoparticles at 1123?K. The main products obtained from the conversion of glycerol in the gas phase were hydroxyacetone, pyruvaldehyde, lactic acid and lactide. FSP ensured uniform dispersion of the active metal on a support material. 相似文献