Surface-Enhanced Raman Scattering and Density Functional Theory Study of 4-Nitrobenzonitrile Adsorbed on Ag and Ag/Pd Nanoparticles

The adsorption and reactivity of 4-nitrobenzonitrile on Ag and Ag/Pd nanoparticles immobilized on quartz surfaces have been studied by means of surface-enhanced Raman scattering (SERS) spectroscopy. It has been found that upon adsorption on Ag/Pd nanoparticles this compound undergoes reduction of the nitrogroup to form 4,4¢-azobis(benzonitrile). This process is due to the catalytic efficiency of the palladium clusters present on the surface of the silver nanoparticles. SERS spectra obtained from pure Ag and from Ag/Pd substrates have been assigned by mean of density functional theory calculations.