Preparation and luminescence properties of WO3:Eu3+@SiO2 nanocomposites
WO 3 :Eu 3+ powder was prepared by microemulsion method with cetyltrimethyl ammonium bromide (CTAB) as a surfactant. The prepared WO 3 :Eu 3+ samples were wrapped with SiO 2 by a coating method. The WO 3 :Eu 3+ @ SiO 2 nanocomposites with the core-shell structure were prepared by controlling tetraethyl orthosilicate (TEOS) content (1, 3, 5 and 7%) and water–alcohol ratio (1:3, 1:1.5, 1:1 and 2:1). The structure, morphology and luminescence properties of the prepared WO 3 :Eu 3+ @ SiO 2 samples were characterized by XRD, SEM, TEM and fluorescence spectra. The results show that the prepared WO 3 :Eu 3+ @SiO 2 nanocomposites are spherical and granular, and the average particle size is below 100 nm. Under the condition of different TEOS contents, the strongest characteristic peak is located at 554 nm in the green light band at the excitation wavelength of 328 nm. Among the different water–alcohol ratio conditions, the prepared WO 3 :Eu 3+ @SiO 2 nanocomposite has the strongest luminescence intensity at the water–alcohol ratio of 1:3, and the excitation wavelength is 328 nm. The excitation spectra measured at 612 nm have prominent characteristic peaks at 362, 394, 422, 465 and 499 nm, which correspond to the transition of 7 F 0 → 5 D 4 , 7 F 0 → 5 L 6 , 7 F 0 → 5 D 3 , 7 F 0 → 5 D 2 and 7 F 0 → 5 D 1 , respectively.
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