Size-controlled synthesis of Pd nanomaterials via proton beam irradiation.

We present a facile one-pot synthetic route for the production of palladium nanoparticles via a simple proton beam irradiation process at room temperature. The synthesis of size-controlled palladium nanostructures was realized just by changing the mean current of the proton beam and by controlling the molar concentration ratios of surfactants to Pd precursors in an aqueous phase-based solution without the addition of any harsh reductants. As the beam current was increased under the same Pd ion concentration conditions, the average diameter of the prepared Pd nanoparticles tended to be decreased. We also found that the size of the synthesized Pd nanocrystals was decreased as the molar ratio of surfactants to palladium ion was increased.