Formation of Bimetallic Fe/Au Submicron Particles with Ultrasonic Spray Pyrolysis

Peter Majerič,Bernd Friedrich,Darja Jenko,Rebeka Rudolf

doi:10.3390/met8040278

Abstract

This article studies the synthesis of bimetallic Fe/Au submicron particles with Ultrasonic Spray Pyrolysis (USP). The combination of Fe oxide particles’ ferromagnetism with Au nanoparticles’ (AuNPs) surface plasmon resonance has gained high interest in biomedical and various other applications. Initial investigations for producing Fe/Au particles with USP were carried out in order to study the particle formation mechanisms. Firstly, three precursor salt solutions (Fe acetate, Fe nitrate and Fe chloride) were used to produce Fe oxide particles and to study their effect on particle morphology through characterization by Scanning and Transmission Electron Microscopy (SEM and TEM) with Energy Dispersive X-ray spectroscopy (EDX). These precursor salts produce three types of submicron particles, a mesh of primary nanoparticles, spherical particles and irregular particles, respectively. Next, different solution combinations of precursor salts of Fe and Au were used with the USP. The obtained particles were characterized, and similarities were then examined in the particle formation of pure Fe oxide and Fe/Au particles. The effects of using different salts were analyzed for the formation of favorable morphologies of Fe/Au particles. The combinations of Fe chloride/Au chloride and Fe chloride/Au nitrate in the precursor solution indicate potential in synthesizing bimetallic Fe/Au submicron particles with the USP process.

Highlights

Several research works have been done for bimetallic Fe/Au nanostructures [1,2], with a strong interest in biomedical applications [3,4], and with an additional intermediate layer between the magnetic Fe core and the plasmonic Au layer [5,6]
Iron-containing precursors were used with Ultrasonic Spray Pyrolysis (USP), in order to understand the morphologies and synthesis mechanisms of Fe oxide particles that are formed inside the USP better
Thermogravimetric analyses (TGA) was done on the precursors in order to select a reaction temperature inside the USP, ensuring Fe oxide particle synthesis

Summary

Introduction

Several research works have been done for bimetallic Fe/Au nanostructures [1,2], with a strong interest in biomedical applications [3,4], and with an additional intermediate layer between the magnetic Fe core and the plasmonic Au layer [5,6]. Joining the properties of these elements produces different effects, such as enhanced catalysis or tunable plasmonic properties, making the hybrid structures useful for a number of applications (catalysis [7], sensors [7], magnetic resonance imaging [3,4,9], photothermal treatment of cancer [3,4,5] and drug delivery systems [3,4,9]). The aim is to obtain gold (Au)-coated iron (Fe) nanoparticles, Metals 2018, 8, 278; doi:10.3390/met8040278 www.mdpi.com/journal/metals

Methods

Results

Conclusion