Assisted laser ablation: silver/gold nanostructures coated with silica

J R González-Castillo,Carlos Lenz Cesar,Ernesto Jiménez-Villar,Eugenio Rodríguez-González,Jacob Antonio Andrade-Arvizu

doi:10.1007/s13204-017-0599-2

J R González-Castillo, Carlos Lenz Cesar + Show 3 more

Open Access

https://doi.org/10.1007/s13204-017-0599-2

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Abstract

The synthesis processes of metallic nanoparticles have seen a growing interest in recent years, mainly by the potential applications of the phenomenon of localized surface plasmon resonance associated with metallic nanoparticles. This paper shows a fast method to synthesize silver, gold and silver/gold alloy nanoparticles coated with a porous silica shell by the assisted laser ablation method in three steps. The method involves a redox chemical reaction where the reducing agent is supplied in nanometric form by laser ablation. In the first step, a silicon target immersed in water is ablated for several minutes. Later, AgNO3 and HAuCl4 aliquots are added to the solution. The redox reaction between the silver and gold ions and products resulting from ablation process can produce silver, gold or silver/gold alloy nanoparticles coated with a porous silica shell. The influence of the laser pulse energy, ablation time, Ag+ and Au3+ concentration, as well as the Ag+/Au3+ ratio, on optical and structural properties of the nanostructures was investigated. This work represents a step forward in the study of reaction mechanisms that take place during the synthesis of nanoscale materials by the assisted laser ablation technique.

Highlights

The study of nanometric structures of different materials is constantly evolving and every day there are a greater number of applications in which we find these nanomaterials (Zhang et al 2005; Rodriguez et al 2008; Kellermann et al 2010; Fuertes et al 2011; Bankura et al 2012; Garcia 2012; Prabhu and Poulose 2012; Liao et al 2013; Liu et al 2014; Al-Azawi et al 2016; Zhang et al 2017)
The synthesis processes of metallic nanoparticles have seen a growing interest in recent years, mainly by the potential applications of the phenomenon of localized surface plasmon resonance associated with metallic nanoparticles
This paper shows a fast method to synthesize silver, gold and silver/gold alloy nanoparticles coated with a porous silica shell by the assisted laser ablation method in three steps

Summary

Introduction

The study of nanometric structures of different materials is constantly evolving and every day there are a greater number of applications in which we find these nanomaterials (Zhang et al 2005; Rodriguez et al 2008; Kellermann et al 2010; Fuertes et al 2011; Bankura et al 2012; Garcia 2012; Prabhu and Poulose 2012; Liao et al 2013; Liu et al 2014; Al-Azawi et al 2016; Zhang et al 2017). In 2008, Jimenez et al demonstrated a novel hybrid physical– chemical method based on a chemical reaction assisted by laser ablation (Jimenez et al 2008) This is a fast and simple method to synthesize metal-core/dielectric-shell NPs in one step and in an aqueous medium. To study the optical and structural properties of Ag/ Au@Silica NPs as a function of growth parameters, samples were prepared by modifying the time used for the target ablation from 1 to 20 min, the concentration of the metal salts AgNO3 and HAuCl4 from 0.05 9 10-3 to 0.35 9 10-3 M and the Ag/Au percentage ratio (100/0, 95/5, 90/10, 85/15, 80/20 and 0/100), respectively. Absorption spectra were obtained on a Cary 5000 UV–Vis–NIR spectrophotometer

Results and discussion

Conclusions

Compliance with ethical standards