O2 and vacancy diffusion on rutile(110):: Pathways and electronic properties

The binding structures and diffusion pathways of molecular oxygen on a defective TiO2(110) surface are studied by means of a recently developed first-principles string molecular dynamics approach. A variety of molecular and dissociated O-2 adsorption states are identified and the kinetics of their interconversion is analyzed. These results, as well as calculations of the electronic properties and of scanning tunneling microscopy (STM) images, are used to discuss recent experimental observations of the interactions between surface oxygen vacancies and the adsorbed oxygen molecule.