A Facile Synthesis of AuAg Alloy Nanoparticles Using a Chemical Reaction Induced by Sputter Deposition of Metal onto Ionic Liquids

Sputter deposition of silver (Ag) onto an ionic liquid (IL) produced Ag nanoparticles whose size was varied greatly dependent on the sputtering conditions. Change in discharge current from 10 to 40 mA increased Ag particle size from 5.7 to 11 nm, though prolongation of sputtering time simply caused a higher concentration of Ag nanoparticles in IL without change in their size. Sputter deposition of Ag onto IL solutions containing HAuCl4 resulted in the appearance of a single surface plasmon resonance peak in the absorption spectra of the resulting solution, and their peak position was red-shifted with an increase in the concentration of HAuCl4. The obtained results clearly indicated that Ag metal species sputter-deposited in IL can reduce HAuCl4 to give AuAg alloy nanoparticles and that their chemical composition varies depending on the initial concentration of HAuCl4.