GEOMETRY OF DOPAMINE ADSORPTION ON RUTILE (110) SURFACE

Abstract

Density functional theory (DFT) and generalized gradient approximation (GGA) have been employed to study adsorption geometry and electronic properties of the system consisting of rutile (110) surface and dopamine molecule. Hubbard U-like term is included to consider more adequately 3d electrons of Ti atoms. Results indicate that dopamine adsorption takes place in a bidentate geometry by forming strong bonds between two molecular oxygens and two titaniums situated on the surface. Geometry changes of molecular atoms, as well as those constituting upmost layer of the surface has been discussed in detail. Reduction in the band-gap width due to the adsorption has been found implying potential interest of the system for light-harvesting solar cells.