Formation of vacancy islands tailored by Pt nanocrystallites and Ar+ sputtering on TiO2(1 1 0) surface

The effect of Ar+ bombardment was studied on TiO2(1 1 0)-(1 n) surface decorated with Pt nanoparticles by scanning tunnelling microscopy (STM). Pt crystallites were fabricated in a large separation by the so-called seeding + growing method described earlier [A. Berko´, G. Klive´nyi, F. Solymosi, J. Catal. 182 (1999) 511]. It was shown that the presence of Pt crystallites results in an enhanced sputtering of the support in the vicinity of the particles at high temperatures. This process causes a dramatic increase in the average corrugation of the substrate and leads to formation of deep nanoditches in the orientation of [0 0 1]. The analysis of the geometry of the nanoparticles revealed that they are decorated with the material of the support. The noble metal nanocrystallites grown in large separation are suitable for the visualization of the accelerated surface diffusion and sputtering in the region around the crystallites. The phenomenon presented here prompts a nanotechnological tool capable of fabricating nanopits in tailored distribution (in the range of 5–200 nm) that is determined by the original Pt nanoparticles formed on the TiO2(1 1 0) surface.