Abstract
Alloying is an important strategy in tailoring the functionality of materials. In metal nanoclusters (NCs), the introduction of a heterometal leads to alloy nanoclusters that often outperform the homometal ones in terms of the physical and chemical properties. In this work, a series of four M-144(PET)(60) alloy NCs (where, M = Au/Ag, PET = -SCH2CH2Ph) are synthesized and characterized. The silver doping into the homogold template (Au-144) leads to more prominent optical absorption features in the steady-state spectrum in the visible range. Femtosecond transient absorption spectroscopy reveals the effect of Ag doping on the electronic relaxation dynamics compared to Au-144 and the pump fluence independent dynamics. Electrochemical results reflect a narrowing of HOMO-LUMO gap (E-g) induced by Ag doping. A temperature dependence of the single-electron charging is also observed for the series of alloy NCs, in which the E-g values of the alloy NCs enlarge as the temperature decreases, which is characteristic of semiconducting behavior.
