Synthesis and Characterization of Mesoporous Europium (Ⅲ) Silicate Molecular Sieves

摘要

The luminescent nanosized Eu-MCM （1∶10） was synthesized by means of sol-gel-assisted self-assembly under basic conditions at room temperature. The results of （）29Si-MAS NMR show that the peaks are Q4, Q3, Q2 [（SiO）4-mSi-（OH）m （m=0, 1, 2）, at -δ111, -δ103, -δ90], and q3, q2, q1, q0 [（SiO）4-nSi-（O-Eu）n （n=1, 2, 3, 4 ）, at -δ83, -δ72, -δ55, -δ47]. The result proves Eu3+ doped Si-O framework. The HRTEM image shows that the regular uniform nanoparticles with a diameter of 15 nm possess large pore with Φ8 nm, which is consistent with the result of N2 adsorption. The patterns of selected-area electron diffraction, XRD, and pore-size distribution plot of Eu-MCM （（1∶10）） show that the sample of Eu-MCM （（1∶10）） possesses the both of crystal and amorphous phases. The FT IR results indicate that the peaks near 970 cm-1 are assigned to the deformation vibration of silanol group. The as-product was calcined at 800 ℃ and the mesoporous material possesses enormous specific areas and large pores, which shows that the mesoporous material is ultrastable.