Nanoparticle nickel

Key Words—Nanoparticles, nanocapsules, rare-earth elements, iron, cobalt, nickel. 

Moreover, stable liquid systems made up of nanoparticles coated with a surfactant monolayer and dispersed in an apolar medium could be employed to catalyze reactions involving both apolar substrates (solubilized in the bulk solvent) and polar and amphiphilic substrates (preferentially encapsulated within the reversed micelles or located at the surfactant palisade layer) or could be used as antiwear additives for lubricants. For example, monodisperse nickel boride catalysts were prepared in water/CTAB/hexanol microemulsions and used directly as the catalysts of styrene hydrogenation [215]. 

For iron, cobalt, nickel, and their alloys, the most sensitive technique for characterizing the particle surface is the measurement of magnetic properties. Thus, we synthesized cobalt nanoparticles of 1.6 nm (ca. 150 atoms), 2 nm (ca. 300 atoms) and 4 nm (a few thousand atoms) mean size. The structure of the particles is hep in the latter case and polytetrahedral in the first two cases. The 4 nm particles display a saturation magnetization equal to that of bulk... 

Late transition metal or 3d-transition metal irons, such as cobalt, nickel, and copper, are important for catalysis, magnetism, and optics. Reduction of 3d-transition metal ions to zero-valent metals is quite difficult because of their lower redox potentials than those of noble metal ions. A production of bimetallic nanoparticles between 3d-transi-tion metal and noble metal, however, is not so difficult. In 1993, we successfully established a new preparation method of PVP-protected CuPd bimetallic nanoparticles [71-73]. In this method, bimetallic hydroxide colloid forms in the first step by adjusting the pH value with a sodium hydroxide solution before the reduction process, which is designed to overcome the problems caused by the difference in redox potentials. Then, the bimetallic species... 

In the early work on the thermolysis of metal complexes for the synthesis of metal nanoparticles, the precursor carbonyl complex of transition metals, e.g., Co2(CO)8, in organic solvent functions as a metal source of nanoparticles and thermally decomposes in the presence of various polymers to afford polymer-protected metal nanoparticles under relatively mild conditions [1-3]. Particle sizes depend on the kind of polymers, ranging from 5 to >100 nm. The particle size distribution sometimes became wide. Other cobalt, iron [4], nickel [5], rhodium, iridium, rutheniuim, osmium, palladium, and platinum nanoparticles stabilized by polymers have been prepared by similar thermolysis procedures. Besides carbonyl complexes, palladium acetate, palladium acetylacetonate, and platinum acetylac-etonate were also used as a precursor complex in organic solvents like methyl-wo-butylketone [6-9]. These results proposed facile preparative method of metal nanoparticles. However, it may be considered that the size-regulated preparation of metal nanoparticles by thermolysis procedure should be conducted under the limited condition. 

The solvent-free controlled thermolysis of metal complexes in the absence or presence of amines is the simple one-pot synthesis of the metal nanoparticles such as gold, silver, platinum, and palladium nanoparticles and Au-Ag, Au-Pt, and Ag-Pd alloy nanoparticles. In spite of no use of solvent, stabilizer, and reducing agent, the nanoparticles produced by this method can be well size regulated. The controlled thermolysis in the presence of amines achieved to produce narrow size dispersed small metal nanoparticles under milder condition. This synthetic method may be highly promising as a facile new route to prepare size-regulated metal nanoparticles. Finally, solvent-free controlled thermolysis is widely applicable to other metal nanoparticles such as copper and nickel... 

Koltypin Y, Fernandez A, Rojas CT, Campora J, Palma P, Prozorov R, Gedanken A (1999) Encapsulation of nickel nanoparticles in carbon obtained by the sonochemical decomposition of Ni(C8H12)2. Chem Mater 11 1331-1335... 

Polshettiwar, V., Baruwati, B. and Varma, R.S. (2009) Nanoparticle-supported and magnetically recoverable nickel catalyst a robust and economic hydrogenation and transfer hydrogenation protocol. Green Chemistry, 11 (1), 127-131. 

A. Salimi, E. Sharifi, A. Noorbakhsh, and S. Soltanian. Direct voltammetry and electrocatalytic properties of haemoglobin immobilized on a glassy carbon electrode modified with nickel oxide nanoparticles. Electrochem. Commun. 8, 1499-1508 (2005). 

Carbon-Supported Nickel-Based Nanoparticles under Superheated Liquid-Film Conditions.452... 

Tong, X., et ah, Enhanced catalytic activity for methanol electro-oxidation of uniformly dispersed nickel oxide nanoparticles - carbon nanotube hybrid materials. Small, 2012. 

As a result of CNT synthesis, catalyst metal nanoparticles (iron, cobalt, nickel) together with amorphous carbon and fullerenes are unavoidably present in the CNT soot. 

Shao et al. [25] prepared Mg Ni from magnesium and nickel nanoparticles produced by hydrogen plasma-metal reaction. Two preparation methods were developed to obtain the compound. One is heating the nanoparticles under 0.10 MPa argon pressure at 430°C and the other is under 3.00 MPa hydrogen pressure at 280°C. No hydrogen storage properties of this material were assessed. 

Figure 2.18 Kinetic of the hydrogenolysis of AsPhs on Ni/Si02 (175°C, 12barH2) and XRD analysis of the nickel nanoparticles resulting from such reaction [136].

Ni(CO)4 is the sole binary carbonyl complex of the elements of group 10 that is stable (Table 8.1). However, very few studies in which Ni(CO)4 is used in the preparation of catalysts have been reported [43]. This is probably due to the difficulty of manipulation of Ni(CO)4 and its very high toxicity. However, surface Ni(CO)4 species have been identified after the interaction of CO with highly dispersed supported nickel catalysts prepared by other routes [44]. Recent interest in the use of Ni(CO)4 has focused on the controlled production of nickel nanoparticles for specific purposes, such as in automotive converters [45]. The use of nickel tetracarbonyl as an agent for the nucleation process in the growth of single-wall carbon nanotubes has also been reported [46]. 

Sapkal SB, SheUce KE, Shingate BB, Shingare MS (2009) Nickel nanoparticle-catalyzed facile and efficient one-pot synthesis of polyhydroquinoline derivatives via Hantzsch condensation under solvent-lfee conditions. Tetrahedron Lett 50 1754-1756... 

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