In situ SERS monitoring of plasmon-driven catalytic reaction on gap-controlled Ag nanoparticle arrays under 785 nm irradiation

Yanqi Liu; Lisheng Zhang; Xuan Liu; Yongzhi Zhang; Yinzhou Yan; Yan Zhao

doi:10.1016/j.saa.2021.120803

In situ SERS monitoring of plasmon-driven catalytic reaction on gap-controlled Ag nanoparticle arrays under 785 nm irradiation

Spectrochim Acta A Mol Biomol Spectrosc. 2022 Apr 5:270:120803. doi: 10.1016/j.saa.2021.120803. Epub 2021 Dec 24.

Authors

Yanqi Liu¹, Lisheng Zhang², Xuan Liu¹, Yongzhi Zhang¹, Yinzhou Yan¹, Yan Zhao³

Affiliations

¹ Institute of Laser Engineering, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China; Key Laboratory of Trans-scale Laser Manufacturing Technology, Ministry of Education, Beijing University of Technology, Beijing 100124, China.
² The Beijing Key Laboratory for Nano-photonics and Nano-structure, Department of Physics, Capital Normal University, Beijing 100048, China.
³ Institute of Laser Engineering, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China; Key Laboratory of Trans-scale Laser Manufacturing Technology, Ministry of Education, Beijing University of Technology, Beijing 100124, China. Electronic address: zhaoyan@bjut.edu.cn.

PMID: 35007906
DOI: 10.1016/j.saa.2021.120803

Abstract

Plasmon-enhanced photocatalysis has attracted considerable attention due to its low energy consumption and high energy throughput. Surface-enhanced Raman scattering (SERS) is a highly sensitive and label-free nondestructive tool to investigate plasmon-driven photocatalytic reactions. Herein, we present a facile method to fabricate gap-controlled Ag nanoparticle (NP) arrays with uniform and high-density distribution of hot spots, which can be employed as both efficient plasmonic photocatalysts and stable SERS platforms. The plasmon-driven catalytic reaction of 4-nitrobenzenethiol (4NBT), which transforms it into p, p'-dimercaptoazobenzene (DMAB), is detected by using an in situ SERS technique at the excited wavelength of 785 nm. According to the temperature and laser power density dependent photocatalytic reaction rates observed on the Ag NP arrays, we quantitatively determined that the reductive coupling of 4NBT is more likely to occur as the gap decreases. The finite-difference time-domain (FDTD) simulation results demonstrate that the plasmonic hot spots are significantly enhanced with a decrease in gap, which in turn reduces activation energy. The gap-controlled Ag NP arrays are efficient for both promotion and detection of plasmon-driven catalytic reactions, and may pave a pathway for implementing efficient plasmonic photocatalytic platforms.

Keywords: Ag nanoparticle arrays; Apparent activation energy; Localized surface plasmon resonance; Photocatalytic reaction; Surface-enhanced Raman scattering.