Sulfide functionalized lanthanide (Eu/Tb) periodic mesoporous organosilicas (PMOs) hybrids with covalent bond: Physical characterization and photoluminescence

摘要

Novel organic-inorganic periodic mesoporous organosilicas (PMOs) were synthesized by linking lanthanide (Tb~(3+), Eu~(3+)) complexes to the framework of mesoporous through the modified 4-mercaptobenzoic acid (MCBA-Si) using co-condensation method in the presence of Pluronic P123 surfactant as a template. 4-mercaptobenzoic acid (MCBA) grafted to the coupling agent 3-(triethoxysilyl)-propyl isocyanate (TEPIC) was used as the precursor for the preparation of periodic mesoporous materials. The two kinds of resulting materials (denoted as Ln-MCBA-PMOs, Ln = Tb, Eu) were characterized in detail by fou-rier-transform infrared spectra, ultraviolet-visible diffuse reflection absorption spectra, ~(29)Si MAS NMR spectra, small-angle X-ray diffraction, nitrogen adsorption/desorption isotherms, photoluminescence spectroscopy and luminescence decay time measurements. The results reveal that luminescent periodic mesoporous materials have high surface area, uniformity in the mesopore structure and good crystallin-ity. Furthermore, the mesoporous material covalently bonded Tb~(3+) complex (Tb-MCBA-PMOs) exhibits the stronger characteristic emission of Tb~(3+)and longer lifetime than Eu-MCBA-PMOs due to the triplet state energy of organic ligand MCBA-Si matches with the emissive energy level of Tb~(3+) very well.