Bimetallic alloy nanoparticles are attractive for their tunable, new, and synergistic properties. Thus a synthesis method for bimetallic alloy nanoparticles with desired structures, compositions, and sizes is in demand. Recently, vacuum sputtering onto a liquid has been emerging as a green approach to create bimetallic nanoparticles dispersed in liquid. Vacuum sputtering generate atoms/clusters from bulk metal targets which subsequently experience collision and growth to form nanoparticles in gas, gas-liquid interface and liquid inserted in sputtered chamber. The liquids are low volatile and can be used to capture the formed nanoparticles. It is versatile to choose the liquids and their functionalities to stabilize nanoparticles and to control particle size. In our study, double target sputtering has been developed to create alloy nanoparticles with tailorable composition via simultaneously sputtering two metal targets and varying sputter currents used for each target. We have chosen liquid polyethylene glycol, PEG, M. W. = 600, as the liquid substrate for stabilizing the sputtered particles. Our research focuses on investigating the possibility of bimetallic solid solution nanoparticles formed at room temperature via double target sputtering of different metal systems. Two metals used including complete miscible, intermetallic compounds, and immiscible systems in the bulk state, i.e. Au/Ag, Au/Cu, and Au/Pt respectively. Our results indicated that the solid solution alloy nanoparticles were produced in each system. In particular, the positions of localized surface plasmon resonance peak positions of Au/Ag nanoparticles were linearly dependent on the compositions of the sputtered nanoparticles, which suggested the alloy formation. Besides, elemental mapping images of the obtained Au/Ag nanoparticles (using a transmission electron microscope (TEM)-energy dispersive X-ray spectroscopy (EDX)) exhibited a uniform distribution of two metals for entire nanoparticles. This further confirmed the formation of bimetallic alloy. Similar results were obtained for Au/Cu and Au/Pt nanoparticles despite the fact that they are not solid solution in the bulk state. Hence, our method is promising for synthesis of various alloy nanoparticles with controllable composition, size, and good colloidal stability.<br/>

Synthesis of alloy nanoparticles via sputtering onto a liquid polymer

256th National Meeting (2018)

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