490 results about "Alloy nanoparticle" patented technology

Nanoparticles of silicon oxide alloys (i.e., oxides of SiMo, SiPt, and SiAl) are produced by laser vaporization of a silicon target and a target of a metal (i.e., Mo, Pt, or Al), in an oxygen containing atmosphere in a diffusion cloud chamber, where the target metal vapors aggregate into novel three-dimensional porous web structures. The structures have a homogeneous composition with a uniform ratio of silicon to the metal.

Methods for making metal-based nanoparticles and inks are disclosed. In accordance with the method of the present invention, molecular metal precursors are reduced in the presence of a reaction medium to form the nanoparticles. The molecular metal precursors are preferably reduced by heating the metal precursor in the medium, by adding a reducing agent, such an aldehyde or a combination thereof. Metal precursor are preferably metal oxides, transition metal complexes or combination thereof. The method of the present invention is used to make high yield nanoparticles with a range of particle size distributions. Nanoparticle formed by the present invention include mixtures of nanoparticle, alloy nanoparticles, metal core shell nanoparticles or nanoparticle comprising a single metal species.

There is provided a method of preparing carbon supported, ternary alloy composition core-shell PtVFe nanoparticles for use as fuel cell electrocatalysts. These catalysts have been found particularly useful for oxygen reduction reactions. The alloy nanoparticles can be assembled on carbon supports which then may undergo subsequent activation and / or calcination treatments. The method, combined with new synthetic feed and processing conditions, provides core-shell PtVFe alloy nanoparticles of 1–3 nm size. The catalyst-produced high monodispersity, controlled composition are highly dispersed, and have a uniform distribution. Finally, the correlation of the preparation and treatment parameters to the ORR catalytic activities of the prepared nanoparticles is described. The catalysts exhibit ORR in the range of 2 to 4 times more than a standard Pt / carbon catalyst.

A method for making nanoparticles via metal salt reduction comprises, first, mixing metal salts in a solvent. Second, a reducing agent is added to the solvent at a temperature in the range of 100° C. to 350° C. Third, the nanoparticles dispersion is stabilized. Fourth, the nanoparticles are precipitated from the nanoparticle dispersion. Finally, the nanoparticles are re-dispersed into the solvent. The metal salt comprises a combination of FeCl2, FeCl3, Fe(OOCR)2, Fe(RCOCHCOR)3, CoCl2, Co(OOCR)2, Co(RCOCHCOR)2, and one of Pt(RCOCHCOR)2, PtCl2. The reducing agent comprises one of MBR3H, MH, M naphthalides, and polyalcohol; wherein R comprises one of H and an alkyl group, wherein M comprises one of Li, Na, and K. Long chain alkyl diols, and alkyl alcohol, can be used as a co-surfactant or a co-reducing agent to facilitate nanoparticle growth and separation.

The present teachings are directed toward single metal and alloy nanoparticles and synthesis methods for preparing single metal and alloy nanoparticles.

An anode material made from nanoparticles, said anode material including a homogeneous mixture of lithium-alloying nanoparticles with active support matrix nanoparticles, is provided. The active support matrix nanoparticle is a compound that participates in the conversion reaction of the lithium battery. The compound is preferably a transition metal compound, with said compound including a nitride, carbide, oxide or combination thereof.An electrode manufactured from the anode material preferably has a porosity of between 5 and 80% and more preferably has a porosity between 10 and 50%. The anode material nanoparticles preferably have a mean linear dimension of between 2 and 500 nanometers, and more preferably have a mean linear dimension of between 2 and 50 nanometers.

The PCB manufactured by spraying conductive ink dispersed with Ag—Pd alloy nanoparticles and curing to form wiring according to the present invention provides reduced migration of Ag ions. Further, the present invention provides a method for manufacturing PCB which exhibits competitive price, and excellent conductivity and anti-migration. As one aspect of the present invention, a conductive ink comprising Ag—Pd alloy nanoparticles, wherein the Ag—Pd alloy nanoparticles includes Pd in the range of from 5 weight % to 40 weight %.

The present teachings are directed toward single metal and alloy nanoparticles and synthesis methods for preparing single metal and alloy nanoparticles.

The invention discloses a three-dimensional structure constructed by using graphene as base units and a preparation method thereof. The graphene three-dimensional structure is formed by stacking and assembling graphene, the shape of the graphene three-dimensional structure is a similar cylinder or a polygonal prism, and the volume of the graphene three-dimensional structure is 0.1-100cm<3>. The graphene three-dimensional structure can contain water, methanol, ethanol, glycol and mixture molecules thereof, and can contain Li<+>, Na<+>, K<+>, Ag<+>, Ca<2+>, Ba<2+>, Mg<2+>, Ni<2+>, Co<2+>, Cu<2+>, Mn<2+>, Cd<2+>, Zn<2+>, Pb<2+>, Pt<2+>, Pd<2+>, Rh<2+>, Al<3+>, Fe<3+>, Au<3+>, Ru<3+> and Pt<4+> metal ions. The graphene three-dimensional structure has rich network space which can be used for filling Ni, Co, Cu, Mn, Fe, Au, Ag, Pt and Ru as well as alloy nanoparticles thereof, can be used for filling polypyrrole, polyaniline, polyacrylic acid, polythiophene, polyacrylamide and polyvinyl alcohol polymers, and can be used for filling protein, amino acid, sugar and enzyme biological molecules.

The present invention relates to a cosmetic pigment composition exhibiting colors in the visible region, which comprises an effective amount of nanoparticles or a mixture of two or more nanoparticles selected from the group consisting of (a) gold nanoparticles exhibiting red color; (b) silver nanoparticles exhibiting yellow color; (c) gold-silver alloy nanoparticles exhibiting flame color; and (d) gold nanoparticles exhibiting blue color, and a color cosmetic composition and a color lotion comprising the pigment composition. According to the present invention, it is possible to prepare pigments exhibiting various colors in the visible region using gold or silver nanoparticles, and a cosmetic pigment composition which can exhibit various colors by mixing the pigments in various compositional ratios, in which precipitation or agglomeration of particles does not occur, and whose color can be maintained for a long time. Also, since the pigment of the present invention is not harmful to the human body unlike conventional metal pigments, and contains gold or silver that is beneficial to health, the pigment can be used in various applications as functional raw materials.

The invention discloses a core-shell structure catalyst for fuel cells and its pulse electrodeposition preparation method. The active component of the catalyst is a nanoparticle with a core-shell structure, and an active metal is cladded in the form of an ultrathin shell on the surface of a carbon carrier loaded metal or alloy nanoparticle serving as a core. The catalyst takes a non-platinum noble metal or transition metal as the core, and adopts more than one of Pt, Ir or Au as the shell. The preparation method includes: preparation of the nanoparticle serving as the core, making of a working electrode for pulse electrodeposition, and preparation of the catalyst by pulse electrodeposition. The catalyst can be used as an anode or cathode catalyst of a low temperature fuel cell. The obtained catalyst has very high stability. Compared with underpotential deposition, the method is simple to operate, has no need for inert atmosphere protection, and is more suitable for large-scale industrial production, also can greatly reduce the noble metal consumption of fuel cells, and greatly reduce the cost of fuel cells, thus having great significance in promoting the commercialization process of fuel cells.

Monodisperse core-shell types of metal, metal oxide, and alloy nanoparticles with variable core diameters and shell thicknesses, and controlled synthesis methods for producing such nanoparticles are provided. Nanocomposite materials fabricated from nanoparticles, and methods for producing such nanocomposite materials are also provided.

The invention provides a nitrogen-doped porous vertical graphene nanowall array. A compact coating layer is formed by means of nickel hydroxide serving as a template and the self-assembly property of dopamine, then high-temperature carbonization is conducted to prepare a nitrogen-doped vertical graphene nanowall array material, in-situ functional modification is conducted on the basis, the compound functional material loaded with noble metal nanoparticles, noble metal alloy nanoparticles, metal oxides, metal sulfide, metal phosphide, conductive polymers and the like is obtained, and application in the fields of supercapacitors, lithium ion batteries, water decomposition, electrochemical catalysis, enzyme-free biosensors and the like is explored.

Belonging to the technical field of material preparation, the invention relates to a preparation method of a nitrogen-doped carbon nanotube wrapped metal iron-cobalt alloy composite material (FeCo-NCNTs). The technical scheme includes: firstly, dissolving a metal salt and a carbon-nitrogen source in water, ethanol or ethylene glycol, mixing the substances evenly, and then performing drying and grinding to obtain a precursor; then putting the precursor in a tubular furnace, in a nitrogen atmosphere, conducting programmed heating to a roasting temperature, and conducting high temperature roasting and grinding to obtain a black powder sample; and then subjecting the black sample to pickling treatment until the pH value of the solution is neutral, and conducting pumping filtration and naturaldrying, thus obtaining the nitrogen-doped carbon nanotube wrapped metal iron-cobalt alloy composite material (FeCo-NCNTs). The obtained composite material can be used as a good electrocatalytic hydrogen evolution catalyst. The composite material prepared by the method provided by the invention has the characteristics of easily available raw materials and low cost, and has important significance inelectrochemical application.

The invention discloses a method for preparing cauliflower nano gold-silver alloy with a surface-enhanced Raman scattering activity, which comprises: mixing 0.001mol / L solution of silver nitrate and 0.001mol / L solution of sodium phytate in a volume ratio of 30:1; heating the mixed solution till the mixed solution boils and keeping the temperature between 90 and 100 DEG C; adding 1 percent solution of trisodium citrate in an amount which is one fiftieth of the volume of the solution of silver nitrate to perform an reaction at 90 to 100 DEG C for 3 hours to prepare nano silver cluster dispersion stabilized by phytic acid; and transferring 12 to 17 milliliters of dispersion into a 25 milliliter beaker, heating the solution to 45 to 65 DEG C with stirring, slowing dripping 1.5 to 2.4 millimeters of 0.01 mol / L solution of chloroauric acid and stirring the mixed solution for 25 to 35 minutes to obtain a sample. The obtained cauliflower nano gold-silver alloy nanoparticles can keep stable for more than 6 months and has high signal repeatability and a surface-enhanced Raman effect. The preparation method is simple and low in cost.

Methods and assemblies for the construction of liquid-phase alloy nanoparticles are presented. Particle formation is directed by molecular self-assembly and assisted by sonication. In some embodiments, eutectic gallium-indium (EGaIn) nanoparticles are formed. In these embodiments, the bulk liquid alloy is ultrasonically dispersed, fast thiolate self-assembly at the EGaIn interface protects the material against oxidation. The assembly shell has been designed to include intermolecular hydrogen bonds, which induce surface strain, assisting in cleavage of the alloy particles to the nanoscale. X-ray diffraction and TEM analyses reveal that the nanoscale particles are in an amorphous or liquid phase, with no observed faceting.

A method is featured for fabricating Carbon-supported AuPt nanoparticle catalysts for fuel cells, and particularly fuel cells using methanol as the fuel. The method prepares AuPt-based fuel cell catalysts having a wide range of controllable Au:Pt ratios. The AuPt catalysis are supportable on both carbon black (C) and C / TiO2 support materials. These materials demonstrate electro-catalytic activity towards CO and methanol oxidation, and O2 reduction. The same catalyst material is useful in constructing both anodes and cathodes, and demonstrates bifunctional activity.

Platinum (Pt)-based alloys are effective catalysts for oxygen reduction reaction (ORR) or fuel oxidation in proton exchange membrane fuel cells (PEMFCs). A wet-chemical approach for preparing monodisperse Pt3Ni, Pt3Co and Pt3Fe nanocubes and Pt3Ni nanoctahedra which are terminated with {100} and {111} facets, respectively, were developed. Such nanoscaled electrocatalysts supported on carbon black with controlled shape, e.g., octahedral configuration, is provided. ORR activity on the Pt3Ni nanoctahedra is ˜5.1 fold higher than that of nanocubes with a similar size, and their C-supported samples are highly active with respect to commercial Pt / C.

A method is featured for fabricating Carbon-supported AuPt nanoparticle catalysts for fuel cells, and particularly fuel cells using methanol as the fuel. The method prepares AuPt-based fuel cell catalysts having a wide range of controllable Au:Pt ratios. The AuPt catalysis are supportable on both carbon black (C) and C / TiO2 support materials. These materials demonstrate electro-catalytic activity towards CO and methanol oxidation, and O2 reduction. The same catalyst material is useful in constructing both anodes and cathodes, and demonstrates bifunctional activity.

The invention provides a preparing method for a high-activity and high-stability composite catalyst for fuel cells and belongs to the technical field of fuel cells. The preparing method includes the steps that firstly, the surface of a Pt / C catalyst is wrapped by a layer of dopamine, and the dopamine is used for adsorbing a metal precursor through the good adsorbing performance on metal cations; secondly, silicon dioxide is used for packaging a polymer, the pyrolysis losses and heat treatment morphology conversion of a polymer precursor are controlled through morphology fixing and range limiting functions of the silicon dioxide, alloy nano particles and an N-doped carbon modified layer are further synthesized through high-temperature pyrolysis under the surface segregation effect of platinum and transition metal, and the low-platinum-nonmetal composite structure catalyst with the hollow alloy nano particles wrapped by N-doped carbon is constructed. According to the preparing method for the high-activity and high-stability composite catalyst for the fuel cells, migration agglomerating and growing in the sintering process of the catalyst are overcome, the size of the particles is effectively controlled, the catalyst has high high-activity surface area, operation is simple, industrial production is easy, and the catalyst can be widely applied to the fuel cells with proton exchange membranes serving as electrolytes.

The invention relates to a method for preparing a high-dispersion precious metal and alloy nanoparticles thereof, which comprises: 1) uniformly stirring glycol and specific surfactant in a certain proportion in an inert atmosphere to prepare milky emulsion; 2) adding solution of precursor of the precious metal into the mixed solution, heating the resulting solution to a given temperature, keeping the temperature for a certain time period with stirring, cooling to room temperature, adding nonpolar solution and extracting; and 3) performing the rotary evaporation of upper solution to remove solvent, washing with ethanol or mixed solution of ethanol and normal hexane, centrifuging and obtaining the high-dispersion precious metal and the alloy nanoparticles thereof. The nanoparticles prepared by the method have uniform particle size and high monodispersity, and can be separated easily; the alloy is controllable in particle size and composition; the process is simple; the preparation cost is low; the solvent system is cheap; and the method is widely applicable and can realize large-scale preparation easily.

The invention belongs to the electrochemical technical field, in particular to a carbon-coated alloy nano-particle electrode material and a preparation method which are used for li-ion batteries. The electrode material body is nano-alloy material; phenolic resins are uniformly coated on the alloy nano-particle to form a core-shell structure by a method of emulsion polymerization, and at last the alloy nano-particle which is coated by the carbon is obtained by high-temperature calcination and carbonization in inertia gas environment. In the structure of the composite material, the nano-alloy particle is uniformly and firmly covered by the carbon which has excellent conductivity and certain expansion contractibility, thereby damping the volume expansion and ensuring the conductivity of the integrated electrode at the same time in the circulation process. By taking the composite material as the material for a cathode material of the li-ion battery, the cathode material of the li-ion battery with high li-content capability, excellent safety and excellent circulation performance can be obtained.

The invention relates to Sn—Cu—Ag alloy nanoparticles, preparation method thereof and ink or paste using the alloy nanoparticles in which the alloy nanoparticles are suitable for metal ink having excellent electrical conductivity or solder materials having low calcinating temperature.

The invention discloses a preparation method for carbon nano tube surface loaded magnetic alloy nano particle composite material, which belongs to the field of electromagnetic wave absorbing material preparation. The preparation method comprises the following steps: after purifying and activating a carbon nano tube, evenly dispersing the carbon nano tube to chloride salt solution of iron, cobalt and nickel, slowing adding an alkali solution dropwise into the solution in the fierce agitation process, and regulating the pH value of the solution and making iron ions, cobalt ions and nickel ions be coprecipitated onto the surface of the carbon nano pipe in the form of hydroxide according to the alloy proportion set when the solution is prepared; taking out a deposit by centrifugation or filtering; and after drying the deposit, carrying out the heat treatment of the deposit in the reducing atmosphere to obtain the carbon nano tube composite material loaded with magnetic alloy particles. The preparation method adopts a simple process. As no impurity element is introduced into the preparation process, the obtained magnetic alloy particles have high degree of crystallinity and excellent magnetic properties. In addition, the method has easy regulation of the alloy components. The composite material prepared by the method is significantly applied in the fields of electromagnetic interference resistance, stealth, microwave darkrooms, and the like.

The invention discloses alloy nanoparticles, a preparation method and applications thereof. According to the method, a metal precursor loaded on a substrate is rapidly reduced at a high temperature, wherein the metal is rapidly nucleated to avoid the generation of the split-phase alloy so as to form the alloy nanoparticles with ultra-small particle size; and by controlling the types of the metal salts in the precursor, the components in the alloy nanoparticles can be effectively regulated. According to the present invention, the FeCoPtPdIr@GO (FeCoPtPdIr alloy particles are loaded on the surface of graphene oxide) prepared in the embodiments of the invention shows excellent electrochemical hydrolysis hydrogen production performance, can stably operate for 150 h under a condition of 10 mA.cm<-2>, has excellent electrochemical stability, and has the Faraday efficiency of 99.4%, wherein the eta 10 of the product of the present invention is equal to 42 mV, and far exceeds the eta 10 of thecommercial Pt / C of 64 mV (the smaller the eta 10, the better the electrochemical hydrolysis hydrogen production performance); and the new thought is provided in the preparation of alloy nanoparticlesand alloy nanometer catalysts, and the development of alloy nanometer catalysts in catalysis and energy is promoted.

CuInS2 nanoparticles have been prepared from single source precursors via microwave irradiation. Also, CuInGaS2 alloy nanoparticles have been prepared. Microwave irradiation methods have allowed an increase in the efficiency of preparation of these materials by providing increased uniformity of heating and shorter reaction times. Nanoparticle growth has been controlled in the about 1 to 5 nm size range by variation of thiolated capping ligand concentrations as well as reaction temperatures and times. Investigation of the photophysical properties of the colloidal nanoparticles has been performed using electronic absorption and luminescence emission spectroscopy. Qualitative nanoparticles sizes have been determined from the photoluminescence (PL) data and compared to TEM images.

This invention provides Cu-Ag alloy conductor slurry and its manufacturing method including: preparing nm particles of Cu-Ag alloy, matching conductor slurry and sintering the slurry, in which, the nm particles are prepared under the mixed atmosphere of H and Ar with the DC arc plasma method and the preparation for the slurry includes: fully mixing terpinyl, EC and absolute alcohol then adding nm particles and fully beating them up to be vibrated by supersonic waves then to be added with glass power to beat them up again and vibrate them with supersonic waves to get the conductor slurry. The sinter temperature is bellow 220deg.C under 1.33Pa. Advantage: the sinter temperature is low not needing protection gas while sintering, the conductive stability is higher than Cu power slurry and ití»s possible to replace Au, Ag and Pd slurry.

The invention discloses a Fe-Co alloy / C composite nanofiber microwave absorbent. The Fe-Co alloy / C composite nanofiber microwave absorbent comprises Fe-Co alloy nanoparticles and carbon nanofiber, wherein the Fe-Co alloy nanoparticles are distributed in the carbon nanofiber or on the surface of the carbon nanofiber uniformly, and are wrapped by a graphitized carbon layer. The invention also discloses a preparation method of the Fe-Co alloy / C composite nanofiber microwave absorbent. The method combines electrostatic spinning with later-stage heat treatment to prepare the Fe-Co alloy / C composite nanofiber microwave absorbent by a one-step method, is simple in process, low in cost and high in yield, and can continuously prepare a large amount of the target product Fe-Co alloy / C composite nanofiber microwave absorbents. The Fe-Co alloy / C composite nanofiber microwave absorbent prepared by the method is a wave absorbing material with excellent comprehensive performance, has the advantages of light weight, wideband, strong absorption performance, convenient, adjustable electromagnetic parameters and the like, and has an excellent application prospect in the technical fields of electromagnetic stealth, electromagnetic shielding, resistance to electromagnetism radiation interference and the like.

The invention relates to a method for preparing a one-dimensional alloy nanometer wire. A chloroformic solution of hexadecyl trimethyl ammonium bromide (abbreviated as CTAB), an aqueous solution of chloroplatinic acid or platinichloride and soluble salt, sylvite, sodium salt or an acidic solution of Ni, Pd, Au, Pb, Fe and Ru metallic ions are injected into a flask and are subjected to mechanical or magnetic stirring; after the solution is evenly mixed, the solution is added with a sodium borohydride solution for reduction, and the mixture is continuously stirred for certain time to obtain the corresponding alloy nanometer wire. The whole preparation process is convenient to operate, can be used for preparing various kinds of the alloy nanometer wires and can realize batch production. The method realizes large-scale preparation of the one-dimensional Pt-M(M=Ni, Pd, Au, Pb, Fe and Ru) alloy nanometer wire. The method has simple operation and low cost; the diameter of the obtained alloy nanometer particle is between 1.5 and 4 nm; and the alloy nanometer particle has large specific surface and thus has high application value in the field of catalysts and other fields.

The present invention discloses a palladium alloy catalyst, a preparation method and applications thereof, wherein the palladium alloy catalyst is alloy nanoparticles formed from a palladium element and a base metal element, and the surface of the alloy nanoparticles has a porous structure. According to the present invention, by introducing the base metal into the palladium metal, the palladium metal content is effectively reduced, the economic cost of the palladium alloy catalyst is effectively reduced, the palladium metal provides the synergistic effect with the base metal, and the palladium alloy catalyst can have high catalytic activity and high stability through the porous structure on the surface; and with the method, the advantages of effectively-reduced catalyst production cost, energy source saving, environment protection and mass-production can be provided.