One-pot synthesis of Au@mSiO2 yolk-shell nanoparticles with enhanced catalytic and surface-enhanced Raman scattering (SERS) properties

Abstract

The yolk-shell nanoparticles (YSNs) are promising functional nanomaterials for a variety of applications such as bio-medicine, catalysis, sensor, lithium battery and detection due to their unique structures and excellent properties. In the past few decades, the synthesis of YSNs generally requires multiple steps to complete, and the process is relatively tedious and complicated. Here, Au@mSiO2 YSNs with good dispersibility were successfully synthesized by a facile one-pot process. The Au core with average diameter of 22 nm can move freely in the cavity and the silica shell with a thickness of 15 nm can effectively prevent Au particle aggregation. The method is a one-pot one-step synthesis of Au@mSiO2 core-shell nanoparticles (CSNs) combined with an organosilicon-assisted etching process. Thanks to the unique properties of Au@mSiO2 YSNs, such as low density and large surface area, we have conducted a series of studies on its properties. The redox reaction of p-nitrophenol (4-NP) was monitored by UV–vis absorption spectrum to investigate the catalytic performance of Au@mSiO2 YSNs. The surface-enhanced Raman scattering (SERS) effect of Au@mSiO2 YSNS was studied using p-aminophenol (PATP) as probe molecule. The results show that Au@mSiO2 YSNs have higher catalytic activity and stronger SERS effect than that of Au@mSiO2 CSNs. The Au@mSiO2 YSNs will have great application prospects in catalysis, biosensing and detection, etc.