A method for making metal nanorods comprises combining a source of metal cations with at least one surfactant to form a mixture, wherein the metal cations are reduced and the metal nanorods are produced. Metal nanorods produced by the method and uses thereof. The metal nanorods are useful in devices such as lateral flow devices.

A metal microparticle coated with metal hydride nanoparticles is disclosed. Some variations provide a material comprising a plurality of microparticles (1 micron to 1 millimeter) containing a metal or metal alloy and coated with a plurality of nanoparticles (less than 1 micron) containing a metal hydride or metal alloy hydride. The invention eliminates non-uniform distribution of sintering aids by attaching them directly to the surface of the microparticles. No method is previously known to exist which can assemble nanoparticle metal hydrides onto the surface of a metal microparticle. Some variations provide a solid article comprising a material with a metal or metal alloy microparticles coated with metal hydride or metal alloy hydride nanoparticles, wherein the nanoparticles form continuous or periodic inclusions at or near grain boundaries within the microparticles.

A variety of polyhedral nanocages are provided having a hollow interior, ultrathin walls, and well-defined facets of metal atoms. The nanocages can include a variety of precious metals such as Pt, Au, Ru, Rh, or Ir. The metal atoms can take a face-centered cubic structure with {111} facets on the surface. The walls can be thin, sometimes less than 1 nm in thickness or only a few atomic layers in thickness. The nanocages can provide for efficient uses of valuable precious metals, among other things, in catalysis. For example, catalysts are provided exhibiting high mass activities in oxygen reduction reactions. Methods of making and methods of using the nanocages and catalysts are also provided.

A metal microparticle coated with metal hydride nanoparticles is disclosed. Some variations provide a material comprising a plurality of microparticles (1 micron to 1 millimeter) containing a metal or metal alloy and coated with a plurality of nanoparticles (less than 1 micron) containing a metal hydride or metal alloy hydride. The invention eliminates non-uniform distribution of sintering aids by attaching them directly to the surface of the microparticles. No method is previously known to exist which can assemble nanoparticle metal hydrides onto the surface of a metal microparticle. Some variations provide a solid article comprising a material with a metal or metal alloy microparticles coated with metal hydride or metal alloy hydride nanoparticles, wherein the nanoparticles form continuous or periodic inclusions at or near grain boundaries within the microparticles.

Provided is a method of manufacturing a metal nano coil which is suitable for mass production and results in a lower manufacturing cost. The method of manufacturing a metal nano coil includes the steps of: forming, with tension applied to a core member composed of nanofiber of a polymer, a metal thin film on a surface of the core member to fabricate a metal-covered nanofiber; reducing the tension of the metal-covered nanofiber; and heating, with the tension reduced, the metal-covered nanofiber to at or above a boiling point or a thermal decomposition temperature of the polymer and at or below the melting point of the metal thin film to vaporize the core member and shrink the metal thin film into a coil form, so that a hollow metal nano coil is produced.

A hard composite composition may comprise a binder and a polymodal blend of matrix powder. The polymodal blend of matrix powder may have at least one first local maxima at a particle size of about 0.5 nm to about 30 m, at least one second local maxima at a particle size of about 200 m to about 10 mm, and at least one local minima between a particle size of about 30 m to about 200 m that has a value that is less than the first local maxima.

The present invention includes composition and methods for the fabrication of very-high-aspect-ratio structures from metallic glasses. The present invention provides a method for nondestructive demolding of templates after thermoplastic molding of metallic glass features.

Provided are methods of producing hollow metal nanospheres (HMNs) having a pre-selected surface rugosity. The methods include combining in a galvanic exchange reaction at a selected pH: a solution comprising cobalt-based nanoparticle (Co.sub.xB.sub.y NP) scaffolds; and a solution comprising a metal, to produce Co.sub.xB.sub.y NP core/metal shell structures. The methods further include oxidizing the Co.sub.xB.sub.y NP cores of the Co.sub.xB.sub.y NP core/metal shell structures to produce HMNs having the pre-selected surface rugosity, where the pH of the galvanic exchange reaction is selected to produce the pre-selected surface rugosity of the HMNs. Also provided are HMNs produced according to the methods, as well as methods of using the HMNs. Compositions and kits that find use, e.g., in practicing the methods of the present disclosure, are also provided.

In one aspect, radioactive nanoparticles are described herein. In some embodiments, a radioactive nanoparticle described herein comprises a metal nanoparticle core, an outer metal shell disposed over the metal nanoparticle core, and a metallic radioisotope disposed within the metal nanoparticle core or within the outer metal shell. In some cases, the radioactive nanoparticle has a size of about 30-500 nm in three dimensions. In addition, in some embodiments, the radioactive nanoparticle further comprises an inner metal shell disposed between the metal nanoparticle core and the outer metal shell. The metal nanoparticle core, outer metal shell, and inner metal shell of the radioactive nanoparticle can have various metallic compositions.

Multifunctional core@shell nanoparticles (CSNs) useful in electrochemical cells, particularly for use as an electrocatalyst material. The multifunctional CSNs comprise a catalytic core component encompassed by one or more outer shells. Also included are electrochemical cell electrodes and electrochemical cells that electrochemically convert carbon dioxide to, for example, useful fuels (e.g., synthetic fuels) or other products, and which comprise multifunctional CSNs, and methods for making the same.