The present invention relates to security elements, comprising (a) a substrate, (b) on at least part of the substrate surface a metal layer, (c) optionally on at least part of the metal layer a dielectric layer, (d) on at least part of the metal layer, or the dielectric layer, a layer obtained by overcoating the metal layer, or the dielectric layer with a composition, comprising (i) silver nanoparticles, (ii) a solvent, (iii) (surface) stabilizing agent(s) and (iv) optionally a binder, and (e) a protective layer on top of layer (d). The maximum absorption wavelength of the silver nanoparticles in layer (d) is controlled by the amount of (surface) stabilizing agent(s) and optionally binder relative to the amount of silver nanoparticles to be preferably in the range of 700 to 1600 nm.

According to embodiments of the present invention, an ink composition is provided. The ink composition includes a plurality of nanostructures distributed in at least two cross-sectional dimension ranges, wherein each nanostructure of the plurality of nanostructures is free of a cross-sectional dimension of more than 200 nm. According to further embodiments of the present invention, a method for forming a conductive member and a conductive device are also provided.

According to embodiments of the present invention, an ink composition is provided. The ink composition includes a plurality of nanostructures distributed in at least two cross-sectional dimension ranges, wherein each nanostructure of the plurality of nanostructures is free of a cross-sectional dimension of more than 200 nm. According to further embodiments of the present invention, a method for forming a conductive member and a conductive device are also provided.

The present disclosure relates to a preparation method and use of a thickness-controllable bismuth nanosheet and its alloy, in order to solve the technical problems that the existing metal catalysts for the conversion of carbon dioxide to formic acid exhibit a low efficiency, a high overpotential, a relatively positive hydrogen evolution potential, and a poor stability. In the present disclosure, a bismuth nanosheet of a single atom layer thickness with a thickness of only 0.7 nm is obtained through an aqueous solution reduction method by using a bismuth salt compound as a raw material, using ethylene glycol ethyl ether as a solvent, and using a highly reductive aqueous solution containing NaBH.sub.4, LiBH.sub.4 or the like as a reducing agent, under a protection atmosphere of an inert gas.

Cu-based nanostructures have excellent catalytic, electronic, and plasmonic performance due to their unique chemical and physical properties. A range of Cu materials including foil, spherical nanoparticles, nanowires, and nanocubes have been explored for catalyzing CO.sub.2 electroreduction. However, practical application of the CO.sub.2 electroreduction reaction requires Cu catalysts hold a high percentage of exposed surface atoms for improved product selectivity. The present disclosure describes a high temperature reduction method to prepare Cu nanosheets with size range from about 40 nm to about 13 μm in a hydrophobic system. The purity of trioctyphosphine (TOP) plays an important role for shape-controlled synthesis of Cu nanosheets. The morphology evolution was investigated by adjusting the feeding molar ratio of TOP/Cu-tetradecylamine complex. The Cu nanosheets formed by the methods of the present disclosure have high surface area and stability in solution for more than three months. These Cu nanosheets have applications in reducing CO.sub.2 to fuels.

A metal matrix nanocomposite includes: 1) a matrix including one or more metals; and 2) nanostructures uniformly dispersed and stabilized in the matrix at a volume fraction, including those greater than about 3% of the nanocomposite.

Desirable methods for larger scale silver nanoplate synthesis are described along with methods for applying a noble metal coating onto the silver nanoplates to form coated silver nanoplates with a desirable absorption spectrum. The silver nanoplates are suitable for use in coatings for altering the hue of a transparent film. The hue adjustment can be particularly desirable for transparent conductive films.

The invention provides a process for producing a nanostructure comprising a first metal having a first reduction potential and a second metal having a second reduction potential, the second reduction potential being more negative than the first reduction potential. The process involves a catalyst which is a salt of a reducing metal. The nanostructure may be in the form of a nanowire. The process can provide true nanoalloy products and core-shell nanostructures. The invention further provides a nanoalloy comprising a first metal having a first reduction potential and a second metal having a second reduction potential, the second reduction potential being more negative than the first reduction potential. The invention provides a nanoalloy with an oxide coating. Also provided are a hydrogen storage module and a transparent conductor comprising an optionally oxide-coated nanoalloy according to the invention. Further provided are uses of the optionally oxide-coated nanoalloy of the invention in a method of hydrogen storage, in the manufacture of a transparent conductor and as a catalyst.

In an example, a device cover may comprise a substrate and a metal luster layer having a lustrous paint formulation applied to an outer surface of the substrate. The lustrous paint formulation may comprise base particles with surfaces partially coated with metal nanoparticles. The metal nanoparticles may be disposed in a non-continuous manner on the base particles.

A modified metal nanoplate and a conductive paste including the same are provided. The modified metal nanoplate includes a metal nanoplate, a first protecting agent, and a second protecting agent. The metal nanoplate has an average width of 0.3-20 m and an average thickness of 10-35 nm. The first protecting agent is disposed on a surface of the metal nanoplate and includes an oxygen-containing polymer. The second protecting agent is disposed on the surface of the metal nanoplate and includes a C6-C12 alkylamine.