The adsorption of acenes on rutile TiO2(110): A multi-technique investigation

The adsorption of benzene, naphthalene, and anthracene on the TiO2(110) surface has been investigated using near edge x-ray absorption spectroscopy (NEXAFS), x-ray photoelectron spectroscopy, and thermal programmed desorption. For all three adsorbates a planar adsorption geometry is found. In contrast to the bonding of benzene and larger acenes to metal surfaces, we find that the interaction is dominated by electrostatic forces between the adsorbed molecules and the TiO2(110) substrate. The fact that the average tilt angle between molecular and surface plane as determined by NEXAFS is substantially different from zero indicates the presence of defect species.