The plasmon-mediated chemical reaction (PMCR) of aromatic
molecules
with different functional groups is the frontier topic in the photochemistry
area. In this work, two typical Ag-plasmon-catalyzed reactions in
aqueous environments are studied, in which the selective reduction
reactions of 2-amino-5-nitrobenzenethiol (2A-5NBT) molecules to 3,3′-dimercapto-4,4′-diaminoazobenzene
(M1) and the reduction of M1 to 2,5-aminobenzenethiol
(M2) by NaBH4 are observed. The mechanism of
these two reactions is discussed combined with the calculated Raman
spectra. These results demonstrate that 2A-5NBT molecules are selectively
catalyzed to M1 in aqueous environments and M1 can be reduced to form M2 in the presence of NaBH4 as a reducing agent. Furthermore, the kinetics of the reduction
reaction are analyzed based on surface-enhanced Raman spectroscopy
(SERS), which conforms to the first-order kinetic process. This work
provides a new perspective on the modulation of selective surface-catalyzed
coupling reactions on 2A-5NBT molecules and facilitates the broadening
of the research field of in situ monitoring of PMCRs by SERS technology.