Ag+ concentration effect on the shape of Au nanomaterials under proton beam irradiation

We describe a synthetic route for the high yield production of Au nanomaterials via a simple proton beam irradiation process. It was observed that the size and shape of the prepared gold nanocrystals using proton beam irradiation were easily controlled by the concentration of silver ions, which was added to the Au growth solution. As the concentration of silver ions was increased, there was an apparent increase in the aspect ratio of Au nanorods produced under the proton beam irradiation. But, when the concentration of silver was too high, the transition of Au nanorods to particles was observed. And also it was shown that when the concentration of silver ions was kept constant, the morphology of Au nanocrystals was effectively controllable from rods to particles by varying the energy fluence of proton beam.