利用淀粉制备碳保护金属Ni、Co纳米粒子

Carbon-protected metallic nanoparticles（nickel and cobalt）composites were prepared by the pyrolysis of the mixture of soluble starch and metallic acetate in N₂ flow via an easy green synthetic route.The obtained samples were highly stable in air.Reducing agent was not used in the experiments.The as-synthesized samples were characterized by XRD,TEM,and N₂ adsorption-desorption analysis.The results of N₂ adsorption-desorption analysis indicated that the obtained samples possessed mesoporous structures and high BET surface areas.     

Improving antifouling performance for the harvesting of Scenedesmus acuminatus using Fe2O3 nanoparticles incorporated PVC nanocomposite membranes

Membrane filtration provided a potential solution to get high quality microalgae biomass and recyclable medium. However, the fouling of membrane by microalgae cells and organic matter greatly affects membrane harvesting efficiency. In this study, membrane performance was tested in terms of flux declining and backwashing recovery for microalgal harvesting. Compared with the unmodified poly(vinyl chloride) (PVC) membrane, the membrane with 1.0% Fe₂O₃ incorporation had a 66% increase in average flux, reaching 138 L m⁻ h⁻¹. Foulants on the membrane surface were characterized using attenuated total reflection-Fourier transform infrared (ATR-FTIR) and confocal laser scanning microscope (CLSM), as well as sodium hydroxide extraction followed by total organic carbon (TOC) quantification and fluorescence excitation–emission matrix (FEEM) identification of organic components. FEEM and TOC analysis of the extracted foulants revealed that the surface of 1.0% Fe₂O₃ incorporated membrane had less fouling than the unmodified PVC membrane, which may be attributed to its hydrophilicity after Fe₂O₃ incorporation. CLSM analysis and ATR-FTIR analysis of the fouled membrane surface further revealed that the protein substance on the 1.0% Fe₂O₃ incorporated PVC membrane was lower than those in the unmodified membrane, which further confirmed the enhanced antifouling performance of the 1.0% Fe₂O₃ incorporated PVC membrane. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47685.     

The synthesis of carbon coated Fe, Co and Ni nanoparticles and an examination of their magnetic properties

Carbon coated Fe, Co and Ni nanoparticles (Fe@C, Co@C, and Ni@C, respectively) have been produced by high pressure chemical vapour deposition. Scanning electron microscopy images prove that carbon coated particles with a Fe, Co, and Ni core are formed. High-resolution transmission electron microscopy images show that the nanoparticles have a size distribution from 2 to 100 nanometers and display the core/shell structure with one or more particles forming the core in a particular shell. From X-ray diffraction peaks the phase of the core material is confirmed and the average particle size is determined from the width of the peaks to be 16, 21, and 19 nm for Fe@C, Co@C, and Ni@C, respectively. The coated nanoparticles are ferromagnetic at least up to 400 K. AC magnetic heating studies have been performed which imply their potential for applications in hyperthermia therapy.     

Co、Mn、Ni纳米粒的制备及其对联氨的催化氧化性能研究

采用浸渍-液相还原法,分别制备了纳米Co、Ni、Mn催化剂,以泡沫镍为集电体,以不同材料作为载体制备电极。采用极化曲线测试了不同催化剂对联氨氧化的催化性能。结果表明,Co和Ni对联氨氧化有明显的催化效果,而Mn基本没有催化效果,Co和Ni相比较,在-0.8 V电位下,Co的电流密度为175 mA/cm2,Ni的达到250 mA/cm2,可见Ni对联氨的氧化反应有较好的催化作用。同时,Vulcan XC-72作为催化剂载体更有助于提高催化剂性能。     

State of arts on the bio-synthesis of noble metal nanoparticles and their biological application

Nanomaterials are materials in which at least one of the dimensions of the particles is 100 nm and below. There are many types of nanomaterials, but noble metal nanoparticles are of interest due to their uniquely large surface-to-volume ratio, high surface area, optical and electronic properties, high stability, easy synthesis, and tunable surface functionalization. More importantly, noble metal nanoparticles are known to have excellent compatibility with bio-materials, which is why they are widely used in biological applications. The synthesis method of noble metal nanoparticles conventionally involves the reduction of the noble metal salt precursor by toxic reaction agents such as NaBH₄, hydrazine, and formaldehyde. This is a major drawback for researchers involved in biological application researches. Hence, the bio-synthesis of noble metal nanoparticles (NPs) by bio-materials via bio-reduction provides an alternative method to synthesize noble metal nanoparticles which are potentially non-toxic and safer for biological application. In this review, the bio-synthesis of noble metal nanoparticle including gold nanoparticle (AuNPs), silver nanoparticle (AgNPs), platinum nanoparticle (PtNPs), and palladium nanoparticle (PdNPs) are first discussed. This is followed by a discussion of these biosynthesized noble metal in biological applications including antimicrobial, wound healing, anticancer drug, and bioimaging. Based on these, it can be concluded that the study on bio-synthesized noble metal nanoparticles will expand further involving bio-reduction by unexplored bio-materials. However, many questions remain on the feasibility of bio-synthesized noble metal nanoparticles to replace existing methods on various biological applications. Nevertheless, the current development of the biological application by bio-synthesized noble metal NPs is still intensively ongoing, and will eventually reach the goal of full commercialization.     

纳米铁的绿色合成及其在环境中的应用研究进展

纳米铁（零价铁及铁氧化物）比表面积大、还原能力强、反应活性高,是一种良好的环境功能材料。传统的纳米铁合成方法中,物理方法对反应所需仪器设备要求较高,化学方法使用的还原剂具有毒性,绿色合成方法能够有效克服传统方法的不足之处。本文首先根据合成途径、纳米铁的类型介绍了利用植物和微生物对纳米零价铁（nZVI）及纳米铁氧化物（IONPs）进行绿色合成的方法,同时论述了制备的纳米铁所表现的特征（如形貌、尺寸、聚集倾向、等电位点）。随后总结了纳米铁通过不同反应机制（吸附、还原、催化氧化）去除环境有机、无机污染物（染料、芳香族化合物、硝酸盐、重金属）的应用。最后指出了纳米铁在绿色合成与实际应用过程中存在的挑战性问题及解决方法,以期为纳米铁今后的深入研究和大规模的工业生产应用提供参考依据。     

磁性Ni/NiO纳米颗粒的制备及其在蛋白分离上的应用

用1∶323的硝酸镍和尿素制备出前驱物Ni2+-oligomer,于450℃下热解2 h,得到平均粒径为2 nm的磁性Ni/NiO纳米颗粒;再利用Ni2+与组氨酸的特异性结合,将Ni/NiO纳米颗粒表面修饰上组氨酸,得到平均粒径为10 nm的磁性his-Ni/NiO纳米颗粒,在大肠杆菌体内进行蛋白吸附并在体外进行提纯。结果表明,his-Ni/NiO纳米颗粒洗脱下来的蛋白与大肠杆菌中的蛋白种类一致,该研究为蛋白分离和纯化提供了一条新思路。     

Fe(Co,Ni)/C纳米复合材料的制备及光催化性能的研究

以葡萄糖为原料,制备出胶体碳球。以碳球为基础,通过Fe(Co,Ni)的盐溶液和硼氢化钠溶液的氧化还原反应,合成了Fe(Co,Ni)/C的纳米复合材料。用于甲基橙降解的光催化测试中。随着光照时间的延长,甲基橙的降解率有着明显的提高。我们推断,起主要作用的是Fe/C纳米复合材料表面所负载的铁和氧化铁的纳米粒子。     

铁、钴、镍、铜和锌催化剂催化氨硼烷水解产氢性能研究

采用浸渍-还原法制备了铁、钴、镍、铜和锌催化剂,考察了其催化氨硼烷水解产氢性能,并优化了钴催化剂的制备条件和反应条件。结果发现,铁催化剂中铁以Fe₂B合金相存在,钴催化剂中钴以金属钴存在,镍催化剂中镍以金属镍和Ni（OH）₂·2H₂O存在,铜催化剂中铜以金属铜和氧化亚铜存在,锌催化剂中锌以Zn₄SO₄（OH）₆·4H₂O存在。铁、钴、镍、铜和锌催化剂催化氨硼烷水解产氢活性由大到小顺序为钴催化剂、镍催化剂、铜催化剂、铁催化剂、锌催化剂。显然,具有金属钴相的钴催化剂、金属镍相的镍催化剂和金属铜相的铜催化剂催化氨硼烷产氢活性高于具有Fe₂B合金相的铁催化剂。锌催化剂在制备条件下不能被还原为金属相,它几乎没有催化氨硼烷产氢活性。氯化钴与还原剂硼氢化钠的物质的量比为1∶1.3、还原温度为303 K时制备的钴催化剂催化BH₃NH₃水解产氢性能最佳。反应动力学计算表明钴催化剂催化BH₃NH₃水解产氢反应对氨硼烷浓度的反应级数为零级,对钴催化剂浓度的反应级数为一级,活化能为58 kJ/mol。     

Synthesis of magnetic Fe3O4@SiO2-(-NH2/-COOH) nanoparticles and their application for the removal of heavy metals from wastewater

In this work, Fe₃O₄@SiO₂-(-NH₂/-COOH) nanoparticles were synthesized for the removal of Cd²⁺, Pb²⁺ and Zn²⁺ ions from wastewater. The results of characterization showed that Fe₃O₄@SiO₂-(-NH₂/-COOH) was superparamagnetic with a core–shell structure. The surface of Fe3O4 was successfully coated with silica and modified with amino groups and carboxyl groups through the use of a silane coupling agent, polyacrylamide and polyacrylic acid. The dispersion of the particles was improved, and the surface area of the Fe3O4@SiO2-(-NH2/-COOH) nanoparticles was 67.8 m²/g. The capacity of Fe₃O₄@SiO₂-(-NH₂/-COOH) to adsorb the three heavy metals was in the order Pb²⁺ > Cd²⁺ > Zn²⁺, and the optimal adsorption conditions were an adsorption dose of 0.8 g/L, a temperature of 30°C and concentrations of Pb²⁺, Cd²⁺ and Zn²⁺ below 120, 80 and 20 mg/L, respectively. The maximum adsorption capacities for Pb²⁺, Cd²⁺ and Zn²⁺ were 166.67, 84.03 and 80.43 mg/g. The adsorption kinetics followed a pseudo-second-order model and Langmuir isotherm model adequately depicted the isotherm adsorption process. Thermodynamic analysis showed that the adsorption of the three metal ions was an endothermic process and that increasing the temperature was conducive to this adsorption.     

Continuous preparation of Fe3O4 nanoparticles combined with surface modification by L-cysteine and their application in heavy metal adsorption

L-cysteine functionalized Fe₃O₄ magnetic nanoparticles (Cys–Fe₃O₄ MNPs) were continuously fabricated by a simple high-gravity reactive precipitation method combined with surface modification through a novel impinging stream-rotating packed bed with the assistance of sonication. The obtained Cys–Fe₃O₄ MNPs was characterized by XRD, TEM, FTIR, TGA and VSM, and further used for the removal of heavy metal ions from aqueous solution. The influence of pH values, contact time and initial metal concentration on the adsorption efficiency were investigated. The results revealed that the adsorption of Pb(II) and Cd(II) were pH dependent process, and the pH 6.0 was found to be optimum condition. Moreover, the adsorption kinetic for Cys–Fe₃O₄ MNPs followed the mechanism of the pseudo-second order kinetic model, and their equilibrium data were fitted with the Langmuir isothermal model well. The maximum adsorption capacities calculated from Langmuir equation were 183.5 and 64.35 mg g⁻¹ for Pb(II) and Cd(II) at pH 6.0, respectively. Furthermore, the adsorption and regeneration experiment showed there was about 10% loss in the adsorption capacity of the as-prepared Cys–Fe₃O₄ MNPs for heavy metal ions after 5 times reuse. All the above results provided a potential method for continuously preparing recyclable adsorbent applied in removing toxic metal ions from wastewater through the technology of process intensification.     

Catalytic etching of {100}-oriented diamond coating with Fe, Co, Ni, and Pt nanoparticles under hydrogen

Etching of a highly {100}-oriented diamond coating, {100}HODC, with hydrogen gas using Fe, Co, Ni, and Pt nanoparticles as a catalyst was examined at high temperatures over 700 °C by high-resolution scanning electron microscopy and Raman spectroscopy. The metal atoms vacuum-evaporated onto the {100}HODC formed nanoparticles themselves when heated at high temperatures; e.g. 700 °C, in a flowing gas mixture of H₂ (10%) + N₂ (90%). At 800 °C, short nano-channels and etch pits holding metal nanoparticles were formed by Fe, Co, and Ni. The shapes of the Co and Ni nanoparticles in the etch pits were affected by the shape of the etch pits; reversed pyramidal shape. On the other hand, the top view of the Fe nanoparticles embedded in the etch pits showed a distorted round shape, probably due to the formation of something such as iron carbide, while the carbon content was unknown. Apparently, etching of the {100}HODC by Pt nanoparticles was observed after the treatment at 1000 °C. The difference in the catalytic etching behavior among these metal particles, the potential etching mechanism of diamonds with hydrogen by metal nanoparticles, probably as melted metal nanoparticles, and the formation mechanism of vacant etch pits were discussed.     

Facile synthesis of magnetic metal (Mn, Fe, Co, and Ni) oxides nanocrystals via a cation-exchange reaction

Magnetic metal (Mn, Fe, Co, and Ni) oxides nanocrystals with small size and uniform size distribution are synthesized via a cation-exchange reaction. Two experimental stages are included in the synthesis of metal oxides nanocrystals. Firstly, Cu(OH)2 decomposes to CuO nanocrystals, induced by free metal cations. Compared to CuO nanocrystals produced without any free metal cation, the free metal cation has an important influence on the shape and size of CuO. Secondly, free metal cations exchange with the Cu2+ cation in the CuO nanocrystals to get Mn3O4, Fe2O3, CoO and NiO nanocrystals by cation-exchange reactions. The magnetic properties of these metal oxides nanocrystals have been investigated, all the nanocrystals are superparamagnetic at room temperature.     

Electrochemical deposition of gold-platinum alloy nanoparticles on an indium tin oxide electrode and their electrocatalytic applications

Gold-platinum (Au-Pt) hybrid nanoparticles (Au-PtNPs) were successfully deposited on an indium tin oxide (ITO) surface using a direct electrochemical method. The resulting nanoparticles were characterized by scanning electron microscopy (SEM), UV-vis spectroscopy, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and electrochemical methods. It was found that the size of the Au-PtNPs depends on the number of electrodeposition cycles. Au-PtNPs obtained by 20 electrodeposition cycles had a cauliflower-shaped structure with an average diameter of about 60 nm. These Au-PtNPs exhibited alloy properties. Electrochemical measurements showed that the charge transfer resistivity was significantly decreased for the Au-PtNPs/ITO electrode. Additionally, the Au-PtNPs displayed an electrocatalytic activity for nitrite oxidation and oxygen reduction. The Au-PtNPs/ITO electrodes reported herein could possibly be used as electrocatalysts and sensors.     

离子液体[BMIm]NTf2中Ni纳米颗粒的制备及其催化性能研究

微波辐射下合成了1-丁基-3-甲基咪唑双三氟甲基磺酰亚胺（[BMIm]NTf2）离子液体,并采用IR和1HNMR验证了其结构。利用化学还原法分别在水溶液和离子液体[BMIm]NTf2中制备了Ni纳米颗粒,采用XRD、TEM对其结构进行表征,并考察这两种纳米Ni颗粒在邻硝基苯催化加氢反应中的催化性能。结果表明,[BMIm]NTf2中制备的Ni纳米颗粒为面心立方结构,粒径在3—30nm。在还原过程中,离子液体同时起到了溶剂和修饰剂的作用,在所生成的M纳米颗粒的表面形成了一层离子液体的修饰层,阻止了Ni纳米粒子之间的团聚;在相同条件下,[BMIm]NTf2中制备的纳米Ni颗粒的催化活性显著高于常规水性介质中制备的Ni催化剂。     

Preparation and characterization of polymer/multiwall carbon nanotube/nanoparticle nanocomposites and preparation of their metal complexes

Carbon nanotube‐polymer nanocomposites were synthesized and characterized successfully. In this work, multiwall carbon nanotubes (MWCNT) were opened using HNO₃/H₂SO₄ mixture and filled by metal nanoparticles such as silver nanoparticles through wet‐chemistry method. The oxidized MWCNT were reacted subsequently with thionyl chloride, 1,6‐diaminohexane, producing MWNT‐amine functionalized. Then the MWCNT containing metal nanoparticles were used as a monomer with different weight percentages in melt polymerization with An and CNCl separately. Furthermore, the polyamide and polytriazine modified MWCNT were used for the preparation of metal ion complexes such as Fe⁺² and La⁺³. The structures and properties of nanocomposites were evaluated by TEM, DSC, TGA, and FT‐IR methods. The chelating behavior and sorption capacities of prepared nanocomposites were carried out by using some metal ions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

离子液体[BMIm]NTf_2中Ni纳米颗粒的制备及其催化性能研究

微波辐射下合成了1-丁基-3-甲基咪唑双三氟甲基磺酰亚胺([BMIm]NTf2)离子液体,并采用IR和1H NMR验证了其结构。利用化学还原法分别在水溶液和离子液体[BMIm]NTf2中制备了Ni纳米颗粒,采用XRD、TEM对其结构进行表征,并考察这两种纳米Ni颗粒在邻硝基苯催化加氢反应中的催化性能。结果表明,[BMIm]NTf2中制备的Ni纳米颗粒为面心立方结构,粒径在3～30 nm。在还原过程中,离子液体同时起到了溶剂和修饰剂的作用,在所生成的Ni纳米颗粒的表面形成了一层离子液体的修饰层,阻止了Ni纳米粒子之间的团聚;在相同条件下,[BMIm]NTf2中制备的纳米Ni颗粒的催化活性显著高于常规水性介质中制备的Ni催化剂。     

The interaction between Cu,Pb, Zn and Ni in their biosorption onto polyurethane‐immobilised Sphagnum moss

The uptake of Cu(II), Pb(II), Zn(II) and Ni(II) was investigated both individually and from mixed metal ion solutions using Sphagnum moss biomass immobilised in a polyurethane support. The data were evaluated using the Langmuir isotherm equation, and sorption capacities were calculated for different concentration ranges. It was concluded that care must be taken in presentation and interpretation of results when this modelling approach is applied at low concentrations. Repeated metal loading cycles also gave lower values for sorption capacity compared with the maximum potential value, due to equilibrium effects. The uptake capacity for the different metals on a weight basis was in the order lead > copper > zinc > nickel, but on a molar basis this changed to copper > lead > nickel > zinc. Sorption from a multi‐component metal system showed that lead and copper competed equally for binding sites and much more effectively than zinc and nickel. Equations were derived to predict the percentage effect on a given metal ion of other metals in a multi‐metal system based their behaviour in the relevant single and binary systems. Copyright © 2005 Society of Chemical Industry