Synthesis of size and shape-selective Au nanocrystals via proton beam irradiation

We describe a synthetic route for the high yield production of Au nanomaterials via a simple proton beam irradiation process. Size and shape-controlled Au nanocrystals were prepared by just varying the ion current and the duration of irradiation. It was observed that the size of the prepared gold nanocrystals was reduced significantly as the ion current was increased for the same irradiation time. Furthermore, we were able to fabricate gold nanorods by using proton beam irradiation in the presence of silver ions, which is known to be critical for the one-dimensional growth of gold nanorods.