Production of Size-Controlled Gold Nanoclusters for Vapor-Liquid-Solid Method.

Shaikha Alketbi,Sumayya M Ansari,Dalaver H Anjum,Alam Saj,Haila M Aldosari,Baker Mohammad

doi:10.3390/nano12050763

Abstract

This study demonstrated the deposition of size-controlled gold (Au) nanoclusters via direct-current magnetron sputtering and inert gas condensation techniques. The impact of different source parameters, namely, sputtering discharge power, inert gas flow rate, and aggregation length on Au nanoclusters’ size and yield was investigated. Au nanoclusters’ size and size uniformity were confirmed via transmission electron microscopy. In general, Au nanoclusters’ average diameter increased by increasing all source parameters, producing monodispersed nanoclusters of an average size range of 1.7 ± 0.1 nm to 9.1 ± 0.1 nm. Among all source parameters, inert gas flow rate exhibited a strong impact on nanoclusters’ average size, while sputtering discharge power showed great influence on Au nanoclusters’ yield. Results suggest that Au nanoclusters nucleate via a three-body collision mechanism and grow through a two-body collision mechanism, wherein the nanocluster embryos grow in size due to atomic condensation. Ultimately, the usefulness of the produced Au nanoclusters as catalysts for a vapor–liquid–solid technique was put to test to synthesize the phase change material germanium telluride nanowires.

Highlights

Accepted: 21 February 2022Gold (Au) nanoclusters had garnered the attention of researchers due to their unique physical and chemical properties, which could be primarily attributed to the high surface area-to-volume ratio [1]
Inspired by the aforementioned research and due to the lack of in-depth investigation of the impact of operational parameters on the synthesis of pure Accepted: February 2022Gold (Au) nanoclusters, we demonstrated a detailed investigation of the influence of various deposition source parameters, namely, dc magnetron sputtering discharge power (P), inert gas flow rate (f ), and aggregation length (L) on Au nanoclusters’ average size and yield
Au nanoclusters are produced in the source chamber, size filtered via a quadrupole mass filter chamber, and deposited on the desired substrate in the deposition chamber

Summary

Introduction

Accepted: 21 February 2022Gold (Au) nanoclusters had garnered the attention of researchers due to their unique physical and chemical properties, which could be primarily attributed to the high surface area-to-volume ratio [1]. Au nanoclusters proved to be of potential application in diverse fields including sensors [2], biomedicine [3], and catalysts [4]. Au in its bulk form does not depict any significant catalytic properties due to its high degree of ionization [5] and was paid less attention to be used as a catalyst as a result. It was only during the late 1970s that the utilization of Au as a catalyst for oxidation was explored, which suggested enhanced catalytic properties for Au nanoclusters of a smaller size range [5]. The dc magnetron sputtering technique, used in this study, has a few advantages over other techniques such as the simplicity in its operation, a highly controlled deposition rate, high-quality nanoclusters, Published: 24 February 2022

Methods

Results

Conclusion