ENHANCING EFFECT OF DEPOSITED SILVER ON SURFACE-ENHANCED RAMAN-SCATTERING FOR CHEMISORBED BENZYL DISULFIDE ON IRON

Benzyl disulfide (BDS) can be adsorbed on HCl- or H2SO4-etched iron pl ate to form self-assembled film. The films were characterized by Fouri er transform surface-enhanced Raman scattering spectroscopy. It is pro posed that the bands in the range of 290 to 236 cm(-1) in the spectra were due to the S-Fe bond. The disappearance of the S-S band, the larg e shifts of the C-S band, and the appearance of the Fe-S band from fre e BDS to the adsorbed molecule on the iron surface suggested that the BDS molecule was chemisorbed perpendicularly on the iron surface in th e form of thiolate. The thiolates formed a film dotted with ferric hyd roxide and silver cluster. The SERS effect of iron covered with BDS ca n be enhanced by the chemically deposited silver film, and the enhanci ng effect was related to the deposition time of silver.