Fabrication and investigation of magnetite nanoparticles with gold shell

A simple room temperature technique of Fe3O4/Au nanocrystals preparation in two-phase system was reported. The organic phase contains the mixture of the octane-based magnetic fluid and chloroauric acid complex with quaternary ammonium compound. AuCl4− was transferred from aqueous solution to octane using N-(2-(didecylamino) ethyl)-N,N-tridecyldecan-1-ammonium iodide as the phase-transfer reagent. The aqueous phase contains the sodium borohydride that was used as a reducing agent. The synthesized core–shell nanoparticles have a particle size of 12.8 nm with a gold shell thickness of approximately 1.2 nm. The principles of interphase synthesis and properties of prepared nanoparticles were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet–visible (UV–vis) and Mössbauer spectroscopies.

► Core–shell nanoparticles were prepared by an interphase synthesis.
► The size of Fe3O4/Au nanoparticles is 12.8 nm with 1.2 nm gold shell.
► Fe3O4/Au nanoparticles are formed in a mixture with particles of gold and magnetite.