Preparation and Characterization of (MCM-41)-Eu2O3 Nanocomposite Materials

Abstract

In the present study, a highly ordered mesoporous silica, nanoscale MCM-41, was synthesized and Eu₂O₃ was successfully prepared into the channels of nanoscale MCM-41 via the following methods: liquid-phase grafting method, thermal diffusion method and microwave-assisted synthesis method. The luminescence of Eu³⁺ is particularly interesting because Eu₂O₃ is one of the most important rare earth oxides and the major emission band is centered near 618 nm (red), which is one of the three primary colours (red, blue and green) from which a wide spectrum of colours can be generated by appropriate mixing. The Eu³⁺ ions show narrow emission bands arising from the 5DJ levels (J = 1, 2 and 3). Several characterization techniques were used to investigate physico-chemical properties of the prepared materials and to elucidate their luminescence properties. The prepared (MCM-41)-Eu₂O₃ nanocomposite materials have the ordered hexagonal mesostructure of MCM-41 and show the properties of luminescence. The detailed luminescence studies of all the nanocomposite materials show that (MCM-41)-Eu₂O₃ present stronger luminescent intensities and higher luminescent quantum efficiencies than bulk Eu₂O₃, indicating that the stability limitation of MCM-41 on the Eu₂O₃ in the channels is a benefit for the luminescence properties of the (MCM-41)-Eu₂O₃ nanocomposite materials. The emission spectra of (MCM-41)-Eu₂O₃ display the characteristic luminescence of Eu₂O₃ and the emission bands of (MCM-41)-Eu₂O₃ in the long wavelength are 5D0 ® 7FJ transitions of Eu₂O₃ in the nanoscale MCM-41. It is believed that a markedly enhanced emission occurs owing to the strong interaction between Eu₂O₃ and MCM-41. Meanwhile, the most effective preparative method (the microwave-assisted synthesis method) introduced in this paper is a very promising method for preparing (MCM-41)-Eu₂O₃ nanocomposite materials.