Surface-enhanced Raman scattering of p−nitrobenzoic acid on Ag-Au alloy nanoparticle surfaces

CHED 1037

Evan A. Hiles, ehiles@linfield.edu, Rachel K. Kaneta, rkaneta@linfield.edu, and Brian D. Gilbert. Department of Chemistry, Linfield College, Unit Box 3210, 190 SW Brumback St., McMinnville, OR 97128
The photoreaction of p−nitrobenzoic acid (PNBA) on Ag−Au nanoparticle alloy surfaces has been studied using surface−enhanced Raman scattering (SERS). Surfaces were prepared by citrate reduction of chloroauric acid and silver nitrate. Extinction spectra confirmed the formation of alloy nanoparticles. The photoreduction of PNBA to form azodibenzoate (ADBA) on surfaces under ambient conditions with 532 nm excitation was monitored by observing the 1450 cm-1 peak of the photoproduct. It was observed that the rate and extent of the photoreaction decreased as the mole fraction of Au in the nanoparticles was increased.