Synthesis, characterization, and enhanced luminescence of CaWO4:Eu3+/SBA-15 composites

Abstract

Considering the combination of lanthanide-doped CaWO4 nanophosphor and mesoporous matrix may contribute to superior luminescent properties, CaWO4:Eu3+/SBA-15 composites were successfully synthesized in a mild condition. The physicochemical properties of the resultant composites were carefully characterized by X-ray diffraction, high-resolution transmission electron microscopy, inductive coupled plasma optical emission spectroscopy (ICP), N2 adsorption–desorption, Fourier transform infrared spectroscopy, and luminescence spectra. It’s found that the incorporation of CaWO4:Eu3+ showed no obvious impact on the ordered mesostructure of the host matrix SBA-15, which, however, led to a decrease of BET surface area from 836 to 187 m2 g−1 for pure SBA-15 and CES (0.5), respectively. ICP results indicated that the real loaded amount of CaWO4:Eu3+ in SBA-15 host was lower than the initial molar ratios (x) of CaWO4:Eu3+ to SBA-15 for all samples. The maximum loaded level of CaWO4:Eu3+ in SBA-15 is about 27.3 %. Moreover, the real Eu3+ dopant concentration increased with the initial molar ratios (x), which showed a maximum of about 6.51 % at x = 0.25. The resultant CaWO4:Eu3+/SBA-15 composites exhibited enhanced-luminescent properties than that of pure CaWO4:Eu3+ nanoparticles, which can be mainly attributed to the variation of Eu3+ dopant concentration and the host-protect effect through interaction between guest molecules and host matrix. The available large surface area, pore volume, and superior luminescent properties would facilitate future applications for the composites.