The effect of doped Pd atoms on the geometries and optical adsorption properties of Au cluster: Au_32−nPd_n (n = 1, 2, 4 and 6)

The geometries and optical adsorption properties of Au_32−nPd_n (n = 1, 2, 4, 6) alloy clusters were investigated within the static and time-dependent density functional theory. Our results confirm that Pd atoms favor to replace the inner Au atoms rather than the surface Au atoms of the cluster, which agrees well with previous reports. The optical adsorption property of the Au₃₂ cluster is significantly changed by the Pd doping. Our calculations show that the optical adsorption of Pd-doped alloy cluster in the visible light region is remarkably enhanced compared to the pure Au₃₂ cluster, especially in the lower energy sections. The analysis of the electronic structures of Au₂₆Pd₆, Au₃₂ and Pd₃₂ were performed to reveal the roles of doped Pd atoms. It is found that the doped Pd atoms increase the density of state around the Fermi level of the alloy clusters, which causes the enhanced optical adsorption of the Au–Pd alloy cluster in the visible light region. - Highlights: • The optical adsorption property of Au–Pd alloy cluster were investigated by TDDFT calculations. • Pd atoms favor the inner site in the Au–Pd alloy cluster. • The orbitals of Pd atoms substantively involve the states around the Fermi level of the alloy cluster. • Pd doping can enhance the optical adsorption of Au cluster under the visible light