Electron stimulated desorption of charged particles from acetate covered rutile TiO2(110)

The interaction of low energy electrons with acetate adsorbed on the (110) surfaces of rutile TiO2 has been studied using electron stimulated desorpti on ion angular distribution, low energy electron diffraction and scanning t unnelling microscopy. The adsorption of acetic acid at room temperature is dissociative, and produces a layer of carboxylate species and surface hydro xyl species in an ordered array. Irradiation of the adsorbate covered TiO2( 110) surface causes the dissociation of the surface species, leading to the desorption of a range of charged particles. The dominant desorption produc ts are the H+ ions. The H+ ESD ion angular distribution can be resolved int o two contributions: those ions desorbed from hydrogen atoms bonded at the oxide substrate, and those desorbed via the rupture of the C-H bonds of the acetate species. The geometry of the ESDIAD pattern led us to propose that the carboxylate species is bound to the Ti4+ ions with the molecular axis perpendicular to the surface.