Promotion of Förster resonance energy transfer in a saponite clay containing luminescent polyhedral oligomeric silsesquioxane and rhodamine dye.

A new hybrid photostable saponite clay with embedded donor-acceptor dyes was prepared and characterized in this work. The saponite is intercalated with a luminescent polyhedral oligomeric silsesquioxane, which transfers the photoexcitation energy directly to an acceptor dye (rhodamine B). The obtained composite material was characterized by means of XRD, TEM microscopy, and UV/Vis and photoluminescence spectroscopy. A physicochemical study showed that the system behaved as an efficient Förster resonance energy transfer pair, owing to the very good spectral overlap of donor emission (λem =510-540 nm) and acceptor absorption in the λ=530-570 nm range. The hybrid material represents the first example of a photonic antenna based on a synthetic saponite clay and can be considered a step forward in the search for new, efficient, and stable materials suitable for light-harvesting applications.