Growth of Rh nanoclusters on TiO2(1 1 0): XPS and LEIS studies

Rhodium clusters were prepared by evaporation on a nearly stoichiometric TiO2(1 1 0) surface. The growth of metal nanoparticles, as a function of rhodium coverage, could be followed by monitoring the Rh 3d5/2 XP peak position and by low energy ion scattering spectroscopy (LEIS). The substrate temperature in the 160-300 K regime during evaporation significantly influences the cluster size, leading to smaller crystallites at low temperature. Annealing the surface results in the agglomeration of rhodium, which commenced at lower temperature for smaller clusters. At high temperatures (∼900 K) encapsulation of rhodium also occurred.