Plasmon-Driven Surface-Catalyzed Reactions

Plasmon photonics in metal nano structures and its application in surface enhanced Raman scattering established the theoretical foundation for surface catalysis reaction, this paper, we mainly researched the plasmon driven surface catalysis reaction in metal nanoparticle- film system, and focused both theoretically and experimentally on the two effect of surface catalysis recation: the enhancement of electric field and hot electrons, using surface enhanced Raman scattering and finite element method.The enhancement of electric field is mainly according to the surface plasmons in metal nanostructure can enhance local electromagnetic field, the p-aminothiophenol(PATP) molecule absorbed on metal surface can be coupled and generated the p,p’-dimercaptoazobenzene(DMAB) under the effect of electromagnetic, which can be detected by surface enhanced Raman scattering. The variation of surface Raman scattering spectra in different nanoparticle- film systems indicated the catalysis reaction was large depended on the number of nanoparticles. The higher Raman intensity of DMAB and stronger enhancement of electric field in dimer-film ststem nanogap are caused by effective coupling of light energy on metal film in hybridized plasmonic gap mod and surface catalysis reaction was easily occured in dimer-film system.The hot electrons is mainly based on surface palsmons decay into photons in the propagating process along metal surface while a part of them were converted into hot electrons, these hot electrons with high energy can be catalyzed the 4-nitrobenzenethiol(4NBT) molecule absorbed on metal surface to p,p’-dimercaptoazobenzene(DMAB), which also can be verified by surface enhanced Raman scattering. The number of plasmonic hot electrongeneration in nanoparticle- film system is proportional to the number of nanoparticles.The priority of plasmonic hot electron generation in dimer- film gap is larger than that of monomer- film gap, which analyzed by the surface electric and charge distribution, so the SERS intensity of dimer- film system is stronger than monomer-film system.Additionally, we also study the influence of material and wavelength to surface catalysis reaction. Because of the simple configuration and convenient fabrication of nanoparticle- film system, our work on this hybrid plasmon mode are of great significance not only in the field of surface catalysis and hot electrons, but also in other Plasmon fields such as senor, photon detection, water splitting, ect.