NOBLE METAL-OXIDE JOINED NANOPARTICLES AND METHOD FOR HIGH-PURITY PRODUCTION OF THE SAME

摘要

Provided is a clean production method with which composite nanoparticles of a high purity wherein one noble metal nanoparticle is joined with one oxide nanoparticle can be produced, with good reproducibility and the uniform formation of a hetero-interface but without toxic residue. The method is characterized in that alloy (A-M) nanoparticles that comprise 0.1 to 30 at.% of a noble metal (M) and base metal (A) and inevitable impurities as the balance and that have a grain diameter of 1 to 200 nm (preferably 1 to 100 nm) are produced in an inert gas; while being conveyed in the inert gas, the alloy (A-M) nanoparticles are heated and brought into contact with an oxidizing gas that has been introduced in order to oxidize the noble metal component (A) in the alloy (A-M) nanoparticles floating in the gas; and the oxidized noble metal component (AxOy) is subjected to phase separation from the noble metal component (M) to obtain composite nanoparticles (M-A­XOy).