A method for preparing a hollow multi-metallic nanostructure, the method including the steps of providing a first metal nanostructure having a plurality of first metal atoms, and performing a synthetic strategy, the synthetic strategy including replacing a portion of the plurality of first metal atoms with a corresponding number of second metal ions, and promoting first metal atom diffusion to provide the hollow multi-metallic nanostructure.

Described herein are metallic excavated nanoframes and methods for producing metallic excavated nanoframes. A method may include providing a solution including a plurality of excavated nanoparticles dispersed in a solvent, and exposing the solution to chemical corrosion to convert the plurality of excavated nanoparticles into a plurality of excavated nanoframes.

Methods for preparing solid metal oxide nanoparticles via controlled oxidation comprising preparing a plurality of metal nanoparticles, contacting the plurality of metal nanoparticles with an aqueous agent to provide metal oxide nanoparticles having a desired particle size, and removing the resulting metal oxide nanoparticles from the aqueous agent. Aspects of the present disclosure also relate to solid metal oxide nanoparticles obtained by this method.

Provided are methods of producing cobalt nanoparticles (Co NPs). The methods include combining a cobalt salt, a capping agent, and a reducing agent, under Co NP synthesis conditions including a temperature selected to produce cobalt nanoparticles of a pre-selected diameter, where the temperature and pre-selected diameter are inversely related. In certain aspects, the methods further include producing hollow gold nano spheres (HGNs) using the cobalt nanoparticles as scaffolds. Also provided are cobalt nanoparticles and hollow gold nano spheres (HGNs) produced according to the present methods. Kits that find use in practicing the methods of the present disclosure are also provided.

Methods for forming nanostructures of various shapes are disclosed. Nanocubes, nanowires, nanopyramids and multiply twinned particles of silver may by formed by combining a solution of silver nitrate in ethylene glycol with a solution of poly(vinyl pyrrolidone) in ethylene glycol. Hollow nanostructures may be formed by reacting a solution of solid nanostructures comprising one of a first metal and a first metal alloy with a metal salt that can be reduced by the first metal or first metal alloy. Nanostructures comprising a core with at least one nanoshell may be formed by plating a nanostructure and reacting the plating with a metal salt.

The present specification relates to a metal nanoparticle. Specifically, the present specification relates to a metal nanoparticle having a cavity.

A metal microparticle coated with metal 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) or nanoparticle inclusions (potentially larger than 1 micron). 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 inclusions 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 nanoparticles, wherein the nanoparticles form continuous or periodic inclusions at or near grain boundaries within the microparticles.

A hollow, two-dimensional nanostructure having a plurality of first metal atoms and a plurality of second metal atoms, the first metal being copper, nickel, cobalt, iron, or a combination thereof and the second metal being gold, platinum, palladium, or a combination thereof.

A process for the synthesis of nanostructured metallic hollow spherical particles, in which the metal is deposited onto sacrificial masks formed in a polymeric colloidal solution by the electroless autocatalytic deposition method. Deposition releases only gaseous products (N.sub.2 and H.sub.2) during the oxidation thereof, which evolve without leaving contaminants in the deposit. The particulate material includes nanostructured metallic hollow spherical particles with average diameter ranging from 100 nm to 5 ?m and low density with respect to the massic metal. A process for compacting and sintering a green test specimen are also described.

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.