A series of silver doped butterfly-like Ti₈Ag₂ clusters with two Ag ions panelled on a Ti₈ surface

Abstract

Silver doped TiO₂ (Ag-TiO₂) materials show high activity and good stability in photocatalysis, but the mechanism could not be illustrated clearly due to their imprecise and inhomogeneous characteristics. Ag-doped titanium-oxo clusters (Ag-TOCs) with an exact crystal structure, which are rarely reported, are beneficial for further understanding structure-property relationships. Herein, six new Ag-TOCs with a butterfly-like Ti₈Ag₂ core have been synthesized through facile solvothermal reactions, in which two Ag ions are successfully linked to the surface of the Ti₈ core. Of interest, the Ti₆ unit of the Ti₈Ag₂ core is similar to that found in the anatase structure and may be a promising model for Ag-TiO₂ materials. The band gaps of these Ag-TOCs show different values mainly affected by different ligands. DFT calculations revealed that the lowest energy bands of Ag-TOCs are attributed to the Ag-to-TiO core charge transfer bands. Additionally, all Ag-TOCs exhibit good photoelectric response and high photodegradation activity towards organic dyes.