Colloidal Au-Ag-Chalcogen-Based Ternary Nanocrystals for Energy Conversion Applications

The optimization of a material functionality requires both the rational design and precise engineering of its structural and chemical parameters. In this work, we show how colloidal chemistry is an excellent synthetic choice... [ view full abstract ]

The optimization of a material functionality requires both the rational design and precise engineering of its structural and chemical parameters. In this work, we show how colloidal chemistry is an excellent synthetic choice for the synthesis of homogeneous and compositionally complex novel nanostructured systems with potential application in the energy conversion field. Specifically, the Au-Ag-chalcogen system has been explored from a synthetic point of view, leading to a set of silver chalcogenide-based hybrid and ternary nanocrystals, including the synthesis of unusual ternary AgxAuyXz (where X = S, Se, Te) phases with different stoichiometry. A comprehensive structural and chemical characterization of all nanomaterials proved their homogeneity and the high degree of compositional control achieved. The work is complemented with the thermal and electric characterization of a ternary Au-Ag-Se nanocomposite with promising results: we found that the use of the ternary nanocomposite represents a clear improvement in terms of thermoelectric energy conversion, compared to a binary Ag-Se nanocomposite analogue.