Luminescent Thermometry by a Y/Eu Binary Layered Rare-Earth Hydroxide (LRH) via In Situ Intercalation with Neutral Terbium(III) Complexes.

Temperature-sensitive luminescent materials have aroused great interest for practical applications in optical sensors. Layered rare-earth hydroxides (LRHs) possess rich interlayer chemistry and adjustable composition; thus, they are the promising candidates for designing functional materials, usually through an ion exchange process. Herein, the intercalation of neutral TbIII complex rather than ion exchange was successfully performed in situ into the gallery of Y/Eu binary LRHs by using a hydrothermal process. Interestingly, the swollen LRHs are chameleon luminophores, exhibiting color emissions from green to pink that were tunable through variations in temperature ranging from 77 to 450 K. Because of the highly sensitive and temperature-dependent emissions, novel optical temperature sensors for 1D and 2D thermal imaging were fabricated by employing the chameleon luminophores, which displayed luminescence capable of reversibly undergoing repeated thermocycles. The present work opens up new fields in layered inorganic materials.