Europium(III) Complex-Functionalized SiO@mTiO Nanospheres for Al-Modulated Multicolor Emission.

A europium(III) hybrid material Eu(tta)bpdc-SiO@mTiO (Htta = 2-thenoyltrifluoroacetone, Hbpdc = 2,2'-bipyridine-3,3'-dicarboxylic acid) was successfully designed and synthesized by the covalent grafting complex Eu(tta)bpdc to SiO@mTiO core-shell nanosphere. The FT-IR, PXRD, XPS, TEM, HRTEM, SAED, TGA and PL were performed to characterize these materials. The results indicate that core-shell nanosphere structure and anatase crystallites of SiO@mTiO are retained well after grafting the europium complex. Hybrid material Eu(tta)bpdc-SiO@mTiO displays uniform nanosphere structure, bright red color and long lifetime, which can serve as a multicolor emission material modulated by using Al ions via the cation exchange approach under a single-wavelength excitation. To the best of our knowledge, this work is the first multicolor emissive sensor for Al ions based on the lanthanide hybrid material.