Synthesis of multiple platinum-attached iron oxide nanoparticles

Multiple, small platinum (Pt, similar to 2 nm) attached iron oxide nanoparticles were successfully synthesized using two different approaches. One approach involves growing Pt nanoparticles onto iron oxide seeds in an organic solvent followed by a phase transfer process. We discovered that the surfactant packing density on the seed NPs played a critical role in multiple Pt nucleation. The presence of Pt nanoparticles on the seeds was confirmed using energy dispersive X-ray spectroscopy and high angle annular dark-field imaging. Alternatively, multiple Pt nanoparticles were deposited onto polyacrylic acid coated iron oxide nanoparticles in aqueous solution where the Pt nanoparticles were linked to the polymer coatings. The capability of growing multiple Pt nanoparticles on oxide seeds will be directly beneficial to both catalytic research and nanomedicine.