Abstract
We have investigated the photochemical characteristics of silver 4-nitrobenzenethiolate (Ag-4NBT) by means of Raman spectroscopy. WhenAg-4NBT is irradiatedwith an argon ion laser at 514.5 nm,its Ramanspectrum changes over time, resulting in the production of 4NBT-capped silver nanoparticles. The surface-enhanced Raman scattering (SERS) spectrum of 4NBT adsorbed on those Ag nanoparticles is subsequently converted to that of 4-aminobenzenethiol (4ABT). These surface-induced photoreduction characteristics were investigated by monitoring the growth of Raman peaks of 4ABT as a function of the laser exposuretime. Water vapor or ambient conditions were moreeffective thanvacuum conditions for the photo reduction of 4NBT to 4ABT. Nonetheless, the occurrence of photolysis even under vacuum conditions suggests that the benzene ring hydrogen atoms might be the H-atom source of the nitro-to-amine group conversion although in ambient conditions water or solvent molecules trapped inside the Ag-4NBT should be the primary H-atom source and facilitate the transfer of electrons, as well as the diffusion of Ag atoms to form highly SERS-active nanoaggregates.
Original language | English |
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Pages (from-to) | 187-192 |
Number of pages | 6 |
Journal | Journal of Raman Spectroscopy |
Volume | 41 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2010 |
Keywords
- 4-nitrobenzenethiol
- Photoreduction
- SERS
- Silver nanoparticle
- Silver salt