Taking advantage of the unique capacity of surface plasmon resonance,plasmon-mediated heterogeneous catalysis has recently come into focus as a promising technique for high performance light-energy conversion.A systematical theoretical investigation was performed to study the photocatalytic redox reaction of aromatic amines and nitro compounds on plasmonic nanostructures.We found that azo compounds were produced during the surface-enhanced Raman spectroscopy experiment of p-aminothiophenol(PATP)and p-nitrothiophenol(PNTP).