Patent ID: 7727500

Claim:
A process for producing nanoparticles of a metal or metal compound of less than 10 nanometers in size comprising forming an aqueous solution of the peroxide of the metal or metal compound having the formula M(OOH) x where M is a metal, where x is 2, 3, 4, or 6 from a hydroxide sol of the metal, diluting the solution to a metal peroxide concentration of between about 0.5% and about 0.85% by weight of the solution at a pH in the range of from about 4.0 to about 6.5, heating the solution to boiling for a period of from about 1 to about 4 hours, cooling the solution, reheating the solution to boiling for a period of between about 1 and about 2 hours, cooling the solution, and reheating the solution to boiling until the peroxide concentration in the solution is essentially zero and separating the nanoparticles.