Wednesday, October 27, 2010

US Patent 7820291 - Core-shell metal-metal oxide nanoparticles

Metal oxide shells have been known to be grown on metal nanoparticles as a passivation layer but these metal oxide shells usually have an amorphous structure having inferior mechanical and chemical characteristics relative to crystalline oxides. This patent from LG Chem teaches an epitaxially grown metal oxide shell on a metal nanoparticle to improve surface properties. Claim 1 reads:   

1. Core-shell type nanoparticles comprising:

a) nanoparticle cores made of a material selected from the group consisting of Au, Ag, Pt, Pd, and alloys of two or more of said metals; and

b) shells made of crystalline metal oxide or metalloid oxide formed by an epitaxial crystal growth at a temperature of 5-40° C. on the surfaces of the nanoparticle cores.