An in situ SERS study of substrate-dependent surface plasmon induced aromatic nitration

Abstract

Here we demonstrate the surface plasmon (SP) induced nitration of aromatic rings by an in situ surface enhanced Raman spectroscopy (SERS) technique. The size feature of the as-prepared Au, Ag and Ag@PDA@Au hierarchical structures allows monitoring the entire reaction process on a single hierarchical structure. With benzenethiol (BT) and HNO 3 as reactants, SP induced aromatic nitration can be successfully realized without the assistance of a conventional acid catalyst, H 2 SO 4 . Experimental and theoretical studies confirm that the nitration reaction leads to para-nitrothiophenol (p-NTP). While control experiments show that SP here functions as a local heating source and the presence of metal is also necessary for this nitration reaction. This SP induced aromatic nitration reaction also displays SERS substratedependent reaction kinetics, which proceeds more rapidly on the Au surface. Higher laser power can generate a stronger photothermal effect, and thus an accelerated reaction rate for this reaction. We believe this finding may broaden the research areas in the SP assisted or induced catalytic reactions.

Hot‐Electron‐Mediated Photochemical Reactions: Principles, Recent Advances, and Challenges

“…In 2015, Huang et al reported an in situ SERS study of substrate-dependent surface plasmon-induced aromatic nitration. [65] In the absence of a conventional acid catalyst (H 2 SO 4 ), pNTP was successfully synthesized by surface plasmon-induced nitration of benzenethiol using HNO 3 . This SP-induced chemical reaction also showed substrate-dependent reaction kinetics, proceeding more rapidly on Au surfaces than on Ag.…”

“…Since 2010, various experimental and theoretical results have supported the production of DMAB from pATP by plasmon-driven surface-catalyzed chemical reactions. [61][62][63][64][65][66][67][68][69][70][71][72] Adv. Optical Mater.…”

Surface- and Tip-Enhanced Raman Spectroscopy in Catalysis

“…Decreasing laser energy and power and changing the polarization are known to affect the catalytic power of the plasmons, although the signal-enhancing effects of the plasmonic particles are thereby sacrificed. 29,72,81 …”

Detection of Chloroalkanes by Surface-Enhanced Raman Spectroscopy in Microfluidic Chip

“…In order to measure the rate of the enzymatic degradation of TCP, the SERS detector based on SK307 may be employed. The idea of reaction monitoring in situ by SERS has been widely realized [38,39]. The success of this approach would depend on the rate of fouling of the SERS substrate by the enzyme and its degradation products.…”