Sputtering onto liquids: a critical review

Abstract

Sputter deposition of atoms onto liquid substrates aims at producing colloidal dispersions of small monodisperse ultrapure nanoparticles (NPs). Since sputtering onto liquids combines the advantages of the physical vapor deposition technique and classical colloidal synthesis, the review contains chapters explaining the basics of (magnetron) sputter deposition and the formation of NPs in solution. This review article covers more than 132 papers published on this topic from 1996 to September 2021 and aims at providing a critical analysis of most of the reported data; we will address the influence of the sputtering parameters (sputter power, current, voltage, sputter time, working gas pressure, and the type of sputtering plasma) and host liquid properties (composition, temperature, viscosity, and surface tension) on the NP formation as well as a detailed overview of the properties and applications of the produced NPs.

Sputtering onto liquids: how does the liquid viscosity affect the formation of nanoparticles and metal films?

“…2b) can be explained by the fact that the diffusion of NPs is slower in such a high-viscosity medium. 1,24 According to the obtained results and data provided by Yonezawa's group 11 we can suppose that in the case of the uniform heating of the whole liquid volume the phenomenon of film formation should be mitigated due to the reduced viscosity of the medium.…”

“…Sputtering onto liquids (SoL) is a green technique aiming primarily at producing colloidal solutions of small metal nanoparticles (NPs) without additional reducing and/or stabilizing reagents. 1 In the SoL approach the metal atoms are sputtered from the target surface due to bombardment by fast noble gas cations and finally reach the surface of the liquid substrate. Then the process can follow one of these two routes: (1) atoms penetrate the liquid surface and form small primary clusters which grow to larger NPs or (2) thin-film forms on the substrate surface.…”

“…2 The NP growth during the SoL process is significantly affected by the host liquid viscosity and its temperature. 1 The viscosity of the liquid medium determines the diffusion rate of atoms, primary metal clusters, and growing NPs in the colloidal solutions and hence regulates the number of collisions between the particles which affects their final size. Since liquid viscosity is correlated with temperature, it is necessary to remember that in the frame of the SoL approach the constant interaction between the sputtering plasma and liquid surface leads to the heating of the host liquid as it was recently shown in previous works.…”

Recent Advancements in Nanobiosensors: Current Trends, Challenges, Applications, and Future Scope

“…Sputtering integrates the ousting of nanostructures on a surface morphology layer by exorcizing them from striking with ions [ 41 , 42 ]. Further, sputtering is often utilized for the confession of a thin film of nanostructures lagged by a mitigating procedure [ 43 ].…”

Composition control of alloy nanoparticles consisting of bulk-immiscible Au and Rh metalsviaan ionic liquid/metal sputtering technique for improving their electrocatalytic activity

“…Various solution-phase methods including chemical reduction, polyol process, microwave-assisted reduction, and sputtering deposition on liquids have been reported. [14][15][16][17][18] The homogeneity of composition in bimetallic NPs is one of the most important factors for optimizing their performance in applications because the characteristics of the NPs are greatly affected by the surface coverage of one of two constituent elements in addition to the whole composition of NPs. In the case of the preparation of bimetallic NPs with chemical reduction of metal ions or complexes as precursors, metal ions with more positive redox potential tend to be deposited more rapidly, resulting in the appearance of segregated metal phases in an NP but not the formation of a homogeneous alloy.…”