A general phase transfer protocol for synthesizing alkylamine-stabilized nanoparticles of noble metals.

The ethanol-mediated phase transfer protocol was extended herein to prepare alkylamine-stabilized nanoparticles of several noble metals by transferring them from aqueous environment into toluene. This method relies on the use of ethanol as a mediator to provide and maintain adequate contact between dodecylamine and metal nanoparticles during the transfer process and involves first mixing the metal hydrosols and an ethanol solution of dodecylamine and then extracting the dodecylamine-stabilized metal nanoparticles into toluene. Alkylamine-stabilized Ag, Pd, Rh, Ir and Os nanoparticles with 7.09, 3.45, 6.89, 2.42 and 4.52 nm in diameter, respectively, could be prepared this way. The self-assembly of dodecylamine-stabilized Ag and Rh nanoparticles was also detected by transmission electron microscopy (TEM).