A method for producing mesoporous platinum nanoparticles without using templating agents is provided. The method involves preparing a solution comprising water, platinum nanoparticle seeds, a platinum salt and a reducing agent, and heating the solution to a temperature between 150° C. and 250° C. at a rate of between 1° C./min and 15° C./min under a pressure of between 5 and 20 atm. The method allows obtaining mesoporous platinum nanoparticles having controlled shape and controlled pore dimensions. The mesoporous platinum nanoparticles are useful as catalysts in chemical precision reactions and for the production of artificial enzymes for diagnostics and nanomedicine applications.

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.

While a water reaction system containing silver ions is irradiated with ultrasonic waves to cause cavitation therein, a reducing agent containing solution, which contains an aldehyde as a reducing agent, is mixed with the water reaction system to deposit silver particles, the solid-liquid separation of which is carried out, and thereafter, the separated silver particles are washed and dried to produce a spherical silver powder which has a closed cavity in each particle thereof.

Provided is a thermosetting resin composition containing: (A) silver particles including secondary particles having an average particle size from 0.5 to 5.0 μm, the secondary particles being formed by aggregation of primary particles having an average particle size from 10 to 100 nm; and (B) a thermosetting resin.

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.

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 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 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.

This invention relates to the nano metal material preparation technology field, especially to the preparation method of one kind, of nano-rings. This invention uses polyvinyl pyrrolidone of different molecular weights as surface-protecting agent and dissolves silver nitrate in the low molecular weight polyvinyl pyrrolidone ethylene glycol solvent under frozen conditions. Frozen conditions can slow down or inhibit silver ions from being reduced to zero-valent silver, to generate silver nanoparticles coated and complexed with both low and high molecular weight polyvinyl pyrrolidone. inyl pyrrolidone of different molecular weight shows different selective absorption of silver, and different stability makes it affect the speed of growth of silver atoms along different crystal faces to different extent, which is better for silver nano-ring production, with higher yield. Silver nano-rings made from this invention features perfect circular shape, smooth surface, oval cross-section, and great crystal structure, and can be used as transparent flexible conductive material.

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.