Abstract
Silver colloids have been prepared by sensitized photochemical reduction of silver nitrate solutions. Substituted aminophenylethenyl-alkylpyridinium dyes, with strongly hydrophobic character, were used as sensitizers. Surface-enhanced resonance Raman (SERR) spectra of the adsorbed dye have been observed during colloid formation. With prolonged irradiation, the spectrum disappears as the dye is consumed in the photochemical reduction. For dye solutions without silver nitrate, only fluorescence is observed. The influence of the attachment of a crown ether ring onto the aminophenyl moiety of the dye and that of the counter ion (Br−,NO3−) on photochemical colloid formation are investigated. For comparison, dye solutions have been added to chemically prepared silver colloids, where EDTA or BH4− were used as reducing agents. Similar SERR spectra are obtained on the photochemically and chemically prepared colloids.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have