A First-Principle Study of Pt Clusters On Anatase TiO2 (101) Surfaces

The absorption properties of Pt_n (n is up to 13) clusters on defect free TiO₂ anatase (101) surfaces have been studied using ab initio pseudopotential calculations based on density functional theory. The (111) crystal plane was chosen for the Pt atom arrangement. The change of the Pt cohesive energy and the electronic structure were investigated with the change of the Pt cluster size. The Pt cluster properties were also compared with a full monolayer Pt thin film to understand thoroughly the Pt island growth on an anatase TiO₂ (101) surface. The results indicate that Pt prefers to absorb on existed Pt clusters rather than on the TiO₂ surface. For the same size of the Pt cluster, different absorption positions, orientation and cluster configurations were examined. The binding energy difference of the 1 layer configuration and several 2 layers configurations for the same number of the Pt atoms (eg. 10 Pt atoms) were compared.   Results showed that the Pt energetically prefers the formation of three-dimensional particles. Different cycles of Pt nanoparticles were also experimentally deposited on TiO₂ nanopowders by use of the atomic layer deposition method.  These Pt/TiO₂ nanoparticles were explored via high resolution transmission electron microscopy and the results validated the theoretical study.