Patent application number | Description | Published |
20080292789 | ONE-DIMENSIONAL METAL AND METAL OXIDE NANOSTRUCTURES - Metal powder (such as tin, titanium, or tungsten powder) is heated in a flowing stream of an inert gas, such as argon, containing a small abundance of oxygen at a temperature to produce metal vapor. The metal reacts with the oxygen to form and deposit one-dimensional nanostructures of oxygen-containing metal on the metal powder (in the case of Ti and W) or on a suitable nearby substrate in the case of the lower melting tin. The metal oxides are not necessarily stoichiometric compounds. Water may be introduced into the flowing inert gas to increase or control the oxygen content. Sulfur vapor or a carbon source may be introduced to dope the nanostructures with sulfur or carbon. Reaction conditions may be modified to vary the shapes of the one-dimensional nanostructures. | 11-27-2008 |
20090004552 | NANOWIRE SUPPORTED CATALYSTS FOR FUEL CELL ELECTRODES - Metal oxide nanowires and carbon-coated metal nanowires are effective as supports for particles of an expensive catalyst material, such as platinum metal group catalyst. Such supported catalysts are useful when included in an electrode on, for example, a proton exchange membrane in a hydrogen/oxygen fuel cell. For example, tin oxide nanowires are formed on carbon fibers of carbon paper and platinum nanoparticles are deposited on the tin oxide nanowires. The nanowires provide good surfaces for effective utilization of the platinum material. | 01-01-2009 |
20100130351 | SYNTHESIS OF RARE EARTH ELEMENT-CONTAINING ALUMINA NANOWIRES - Rare earth element(s) doped alumina nanowires are formed by a thermal evaporation method in which vapor from aluminum powder and vapor from a rare earth element compound (such as an halide) are reacted in an oxygen-containing inert gas stream to form alumina which deposits as alumina nanowires and as a rare earth element and oxygen-containing material that deposits with and/or on the alumina nanowires. Where the RE-doped alumina nanowires are to be used as catalyst supports, a catalyst material, such as platinum, may be deposited as small particles on the nanowires. | 05-27-2010 |
20100316873 | ONE-DIMENSIONAL METAL NANOSTRUCTURES - Tin powder is heated in a flowing stream of an inert gas, such as argon, containing a small concentration of carbon-containing gas, at a temperature to produce metal vapor. The tin deposits as liquid on a substrate, and reacts with the carbon-containing gas to form carbon nanotubes in the liquid tin. Upon cooling and solidification, a composite of tin nanowires bearing coatings of carbon nanotubes is formed. | 12-16-2010 |
20110197710 | Making metal and bimetal nanostructures with controlled morphology - A method of making metal nanostructures having a nanometer size in at least one dimension includes preparing an aqueous solution comprising a cation of a first metal and an anion, and mixing commercial elemental powder particles of an elemental second metal having a greater reduction potential than the first metal with the aqueous solution in an amount that reacts and dissolves all of the second metal and precipitates the first metal as metal nanostructures. The temperature and concentration of the aqueous solution and the selection of the anions and the second metal are chosen to produce metal nanostructures of a desired shape, for example ribbons, wires, flowers, rods, spheres, hollow spheres, scrolls, tubes, sheets, hexagonal sheets, rice, cones, dendrites, or particles. | 08-18-2011 |
20120003563 | POROUS DENDRITIC PLATINUM TUBES AS FUEL CELL ELECTROCATALYSTS - Platinum particles have been formed as porous, hollow tubular dendrites by using silver dendrite particles in a galvanic replacement reaction conducted in an aqueous solution of a platinum compound. The dendritic platinum particles have been found useful as catalysts and particularly useful as a hydrogen-oxidation electrocatalyst and/or an oxygen-reduction catalyst in a polymer electrolyte membrane fuel cell. | 01-05-2012 |
20120241192 | MICROFIBER SUPPORTED METAL SILICIDE NANOWIRES - An arrangement of elongated nanowires that include titanium silicide or tungsten silicide may be grown on the exterior surfaces of many individual electrically conductive microfibers of much larger diameter. Each of the nanowires is structurally defined by an elongated, centralized titanium silicide or tungsten silicide nanocore that terminates in a distally spaced gold particle and which is co-axially surrounded by a removable amorphous nanoshell. A gold-directed catalytic growth mechanism initiated during a low pressure chemical vapor deposition process is used to grow the nanowires uniformly along the entire length and circumference of the electrically conductive microfibers where growth is intended. The titanium silicide- or tungsten silicide-based nanowires can be used in a variety electrical, electrochemical, and semiconductor applications. | 09-27-2012 |
20120308818 | ONE-DIMENSIONAL METAL NANOSTRUCTURES - Tin powder is heated in a flowing stream of an inert gas, such as argon, containing a small concentration of carbon-containing gas, at a temperature to produce metal vapor. The tin deposits as liquid on a substrate, and reacts with the carbon-containing gas to form carbon nanotubes in the liquid tin. Upon cooling and solidification, a composite of tin nanowires bearing coatings of carbon nanotubes is formed. | 12-06-2012 |