The disclosed subject matter is directed to a method for producing nanoparticles, as well as the nanoparticles produced by this method. In one embodiment, the nanoparticles produced by the disclosed method have a high defect density. A solution including cerium nitrate hexahydrate is combined with a solution including hexamethylenetetramine to form a combined aqueous solution. After a period of time, the combined aqueous solution is combined with a solution including copper nitrate trihydrate to form a further aqueous solution. The further aqueous solution is then mixed to produce nanoparticles.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under Award No. DMR-0213574 awarded by the National Science Foundation and Grant No. DOE DE-FG02-05ER15730 awarded by the Department of Energy. The government has certain rights in the invention.