Bimetalic (AuPt)₄ nano-clusters adsorbed on TiO₂ nano-wires: A density-functional-theoretic study

We performed density-functional-theoretical calculations for the putative low energy (AuPt)₄ isomer nanoclusters adsorbed on (TiO₂)₃₇ prolate-like nano-wire substrate. We studied the adsorbtion of the bimetallic nanoclusters on the triangular face of the nano-wire. Our results suggest that the stability energy of the complex (cluster and wire) increases during the adsorption process with respect to the free standing cases significantly. It was found that the preferred configurations of the adsorbed clusters in terms of energy are those where both metallic atoms (Au and Pt) are in contact with the surface. Results on the partial reconstruction of the clusters after adsorption and the variations in interatomic distances during the adsorption process are also reported. We briefly discuss the optical properties of the system when using Hubbard corrections (U) for the Ti and O atomic orbitals in the case of the pristine (TiO₂) wire and for the bimetallic adsorbed on the wire. Finally, we briefly comment on some experimental results of similar systems adsorbed on (TiO₂) surfaces.