Plasmon-driven photocatalytic properties based on the surface of gold nanostar particles

Yiyuan Zhang; Chengpeng Zhao; Xueyan Wang; Shipeng Sun; Duan Zhang; Lisheng Zhang; Yan Fang; Peijie Wang

doi:10.1016/j.saa.2021.120240

Plasmon-driven photocatalytic properties based on the surface of gold nanostar particles

Spectrochim Acta A Mol Biomol Spectrosc. 2022 Jan 5:264:120240. doi: 10.1016/j.saa.2021.120240. Epub 2021 Jul 29.

Authors

Yiyuan Zhang¹, Chengpeng Zhao¹, Xueyan Wang¹, Shipeng Sun¹, Duan Zhang¹, Lisheng Zhang², Yan Fang¹, Peijie Wang¹

Affiliations

¹ The Beijing Key Laboratory for Nano-Photonics and Nano-Structure, Department of Physics, Capital Normal University, Beijing 100048, China.
² The Beijing Key Laboratory for Nano-Photonics and Nano-Structure, Department of Physics, Capital Normal University, Beijing 100048, China. Electronic address: lszhang@cnu.edu.cn.

PMID: 34352503
DOI: 10.1016/j.saa.2021.120240

Abstract

Surface plasmon resonance (SPR) generated in gold nanoparticles can induce the conversion of p-Aminothiophenol (PATP) molecules into p,p'-dimercaptoazobenzene (DMAB) molecules by coupling reaction under the action of excitation light. Molecular detection of samples by surface enhanced Raman spectroscopy (SERS) techniques allows the study of their plasma-driven photocatalytic reaction processes. In this study, we used gold nanostars (GNS) as the substrate to study its catalytic performance and sensitivity. On this basis, catalytic substrates of gold nanospheres (GNPs) were prepared for comparison. The catalytic reactions of PATP molecules on each of the above two substrates were systematically investigated under 633 nm laser irradiation. The reduction process was subsequently observed by introducing NaBH₄ solution. The results show that photocatalytic reactions can be achieved on both substrates under laser excitation at the same wavelength. However, the catalytic and reduction reaction rates on GNSs as a substrate are much faster than those of GNPs. This phenomenon may be due to the abundant nano-branched microstructures on the surface of GNSs, which will generate more and stronger local surface plasma hot spots under the irradiation of excitation light. In order to test the above hypothesis, the surface electromagnetic field distribution of two nanostructures was numerically simulated using the finite-difference time domain (FDTD) method. It is found that the star-like nanostructures not only have the same inter-particle hot spot system as the spherical nanostructures, but also have a large number of high-intensity single-particle hot spot systems arising from the abundance of branched nanostructures on their own surfaces. Compared with the spherical nanostructures, they are characterized by a dual hot spot system, which accelerates the photocatalytic reaction rate. The above experiments are of some reference significance for the in-depth study of multi-branched nanostructures and surface plasma distribution properties and their applications.

Keywords: Finite-difference time domain (FDTD); Gold nanostars; Photocatalytic reaction; Surface enhanced Raman spectroscopy (SERS); Surface plasma.