Synthesis and characterization of novel luminescent europium(iii) hybrid materials with a host based on titania–mesoporous silica or alumina–mesoporous silica

Abstract

The luminescent mesoporous hybrids, Eu(M-BDA)₂(TTA-SBA15)₃ and Eu(M-BDA)₂(TTA-MCM41)₃ (M = Ti, Al), were obtained after the coordination reaction between Eu³⁺ ions and a functionalized organic ligand (TTA-SBA15 or TTA-MCM41 and M-BDA (M = Ti, Al)) followed by the hydrolysis cross-linking reaction. All the mesoporous hybrids were found to retain their highly ordered mesoporous structures and possessed good thermal stability characterized by FTIR, SAXRD, TEM, N₂ adsorption–desorption curves, and TG analyses. Especially the photoluminescence behaviors (e.g., photoluminescent spectra, luminescence decay analysis, and ⁵D₀ quantum efficiency) of the Eu³⁺ hybrid materials were investigated in detail. Results showed that SBA-15-type mesoporous hybrids Eu(M-BDA)₂(TTA-SBA15)₃, with larger pore sizes than the corresponding MCM-41-type hybrids Eu(M-BDA)₂(TTA-SBA15)₃, presented longer luminescent lifetimes and higher quantum efficiency than the latter because of spatial confinements of mesoporous matrix nanochannels. The Al–O based mesoporous hybrids also exhibited more excellent luminescent properties than the corresponding Ti–O based hybrids, suggesting that the Al–O host was more beneficial to Eu³⁺ ion luminescence than the Ti–O host. The quantum efficiency of Eu(Al-BDA)(TTA-SBA15)₃ was high even up to 43.17%.