Raman experimental and DFT theoretical studies on the adsorption behavior of MHBA on silver nanoparticles

we have obtained a high quality surface-enhanced Raman scattering (SERS) spectrum of m-hydroxybenzoic acid (MHBA) on the surfaces of silver nano-particles. In theoretical calculation, models of MHBA adsorbed on the surfaces of silver nano-particles were established and each of them corresponds to an experimental configuration. The Raman vibrational wavenumbers of these models using DFT-B3PW91 with lanl2dz were calculated; and it was compared with experimental spectrum. Analyzing the comparison of the results of theoretical calculation and experimental spectrum, we found out the actual configuration of MHBA on the surfaces of silver nano-particles. In our paper, we also prove that the simplified models are probably reasonable to describe some surface enhanced Raman experiments.