Preparation and Growth Mechanism of Pt/Cu Alloy Nanoparticles by Sputter Deposition onto a Liquid Polymer

Abstract

We use a green sputtering technique to deposit a Pt/Cu alloy target on liquid polyethylene glycol (PEG) to obtain well-dispersed and stable Pt29Cu71 alloy nanoparticles (NPs). The effects of sputtering current, rotation speed of the stirrer, sputtering time, sputtering period, and temperature of PEG on the particle size are studied systematically. Our key results demonstrate that the aggregation and growth of Pt/Cu alloy NPs occurred at the surface as well as inside the liquid polymer after the particles landed on the liquid surface. According to particle size analysis, a low sputtering current, high rotation speed for the stirrer, short sputtering period, and short sputtering time are found to be favorable for producing small-sized single crystalline alloy NPs. On the other hand, varying the temperature of the liquid PEG does not have any significant impact on the particle size. Thus, our findings shed light on controlling NP growth using the newly developed green sputtering deposition technique.

Plasma-Induced Heating Effects on Platinum Nanoparticle Size During Sputter Deposition Synthesis in Polymer and Ionic Liquid Substrates

“…While this is not useful if wanting to study small differences between particle sizes in different liquids, the heating effect did help to produce larger particles which were not significantly larger than those produced by others. 11 , 20 , 21 However, more control of the temperature with a heating stage would be preferable for a more constant temperature.…”

“…So far, many different materials have been produced such as Au, 2 − 10 Pt, 11 − 18 Pd, 12 Ag, 19 and various alloy and core shell configurations. 20 − 24 In order to modify and change the size of the nanoparticles, there are various methods and techniques presented in the literature, and the substrate temperature seems to be the most effective with Au nanoparticles. 4 , 5 , 7 There has been some indication that the liquid substrate temperature affects Pt nanoparticle size much less than for Au and Cu, 20 however it is not known to what extent.…”

“… 20 − 24 In order to modify and change the size of the nanoparticles, there are various methods and techniques presented in the literature, and the substrate temperature seems to be the most effective with Au nanoparticles. 4 , 5 , 7 There has been some indication that the liquid substrate temperature affects Pt nanoparticle size much less than for Au and Cu, 20 however it is not known to what extent. As these nanoparticles are extremely useful catalysts, it would be helpful to tailor their size for the relevant application.…”

Synergistic Effect of the Oleic Acid and Oleylamine Mixed-Liquid Matrix on Particle Size and Stability of Sputtered Metal Nanoparticles

“…4,15,25,26 The studies in this field reveal important roles of the liquid matrix in the growth behavior, size control, and colloidal stability of the sputtered nanoparticles. [1][2][3][4][5][6][13][14][15][16][17][18][19][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] Evaluating the impact of the physicochemical properties of the liquids on the particle size helped understand the particle formation. 6,18,19,[27][28][29][30][31][32][33][34][35][36][37][38] For example, when Au was sputtered onto ionic liquids, the particle nucleation could o...…”

“…[1][2][3][4][5][6][13][14][15][16][17][18][19][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] Evaluating the impact of the physicochemical properties of the liquids on the particle size helped understand the particle formation. 6,18,19,[27][28][29][30][31][32][33][34][35][36][37][38] For example, when Au was sputtered onto ionic liquids, the particle nucleation could occur on the liquid surface and growth could occur on the liquid surface and/or in the bulk liquid. [27][28][29][30]…”