Novel light-emitting clays with structural Tb(3+) and Eu(3+) for chromate anion detection

Tb(3+) and Eu(3+) ions were encapsulated for the first time in the inorganic layers of a synthetic saponite clay following a one-pot synthetic approach. The co-presence of the two metal ions led to tuneable light-emitting properties, promoted by an efficient Tb(3+) → Eu(3+) energy transfer and enhanced Stokes shift character. To our knowledge, the so-prepared luminescent material was tested for the first time as an optical sensor for the detection of chromate anions in water.