Structure of low coverage Ni atoms on the TiO2(1 1 0) surface – Polarization dependent total-reflection fluorescence EXAFS study

The structure of low coverage Ni atoms on the TiO2(1 1 0) surface was studied using polarization dependent EXAFS. We found that Ni atoms interacted with oxygen atoms at the 〈 1 1 ¯ n 〉 step edges, where atomically dispersed Ni species were found with Ni–O distances at 0.199 ± 0.002 and 0.204 ± 0.003 nm in parallel and perpendicular directions to the TiO2(1 1 0) surface, respectively. The location corresponded to the virtual Ti site if the next TiO2 layer was created on the topmost TiO2 surface. The Ni location was mainly determined by the dangling bond directions of the surface oxygen atoms.