Ru-core/Cu-shell bimetallic nanoparticles with controlled size formed in one-pot synthesis
Résumé
Suspensions of bimetallic nanoparticles (NPs) of Ru and Cu have been synthesized by simultaneous decompn. of two organometallic compds. in an ionic liq. These suspensions have been characterized by Anomalous Small-Angle X-ray Scattering (ASAXS) at energies slightly below the Ru K-edge. It is found that the NPs adopt a Ru-core, a Cu-shell structure, with a const. Ru core diam. of 1.9 nm for all Ru : Cu compns., while the Cu shell thickness increases with Cu content up to 0.9 nm. The formation of RuCuNPs thus proceeds through rapid decompn. of the Ru precursor into RuNPs of const. size followed by the reaction of the Cu precursor and agglomeration as a Cu shell. Thus, the different decompn. kinetics of precursors make possible the elaboration of core-shell NPs composed of two metals without chem. affinity. [on SciFinder(R)]