Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Metal catalyst particles are deposited on carbon nanotubes by preparing a silane solution of a metal catalyst salt, e.g. platinum or ruthenium chloride, immersing an electrically conducting substrate carrying nanotubes in the silane solution to yield a composite structure of substrate, nanotubes and catalyst, and reducing the composite structure to yield a composite of substrate, carbon nanotubes and metallic catalyst particles.