Selective Plasmon-Induced Oxidation of 4-Aminothiophenol on Silver Nanoparticles

Selectivity in plasmonic chemistry is typically achieved using bimetallic nanostructures. Herein, we show that monometallic silver nanoparticles can also drive highly selective interfacial transformations, oxidation reactions particularly. This is illustrated through a close inspection of tip-enhanced Raman spectral images of 4-aminothiophenol (ATP)-functionalized Au vs Ag nanoparticles. We find that whereas the thoroughly described dimerization reaction to form 4,4 '-dimercaptoazobenzene dominates the response on Au, highly selective oxidation on Ag nanoparticles exclusively leads to 4-nitrothiophenol. We explore the origin of the distinct reaction pathways on Ag vs Au nanostructures.

Automated summary

Selective interfacial transformations, particularly oxidation reactions, can be achieved using monometallic silver nanoparticles instead of bimetallic nanostructures. The tip-enhanced Raman spectroscopy images of ATP-functionalized Au and Ag nanoparticles show that while dimerization dominates on Au leading to 4,4'-dimercaptoazobenzene, oxidation exclusively leads to 4-nitrothiophenol on Ag nanoparticles. The distinct reaction pathways on Ag vs Au nanostructures are explored.