Surface enhanced Raman scattering with methyl-orange on Ag-TiO 2 nanocomposites: A computational investigation.

The influence of changing Ag concentration in a Ag-TiO2 nanocomposite system was investigated with molecular dynamics (MD) simulations for both a fixed as well as varying number of the surfactant MO adsorbed onto the nanocomposite. Density functional theory (DFT) simulations were performed to investigate the conditions for charge transfer from the MO surfactant via the highest occupied molecular orbitals (HOMO), lowest unoccupied molecular orbitals (LUMO) as well as the electrostatic potentials. It is observed in this study that the bonding mode of the surfactant contributes greatly to the observed Raman scattering enhancement.