Synthesis and luminescence properties of Eu3+ doped sodalite phosphors using kaolin

Abstract

In this paper, kaolin was used to synthesise the europium-doped sodalite phosphors (Na8(AlSiO4)6(Cl)2:Eu3+) through the hydrothermal method and then roasting processes. The influence of anion type and concentration, sodium hydroxide concentration, Eu concentration, the roasting temperature and time on the synthesized samples were investigated. Scanning electron microscopy, X-ray diffraction and photoluminescence spectroscopy were applied to detect the crystallization, morphology and luminescence intensity of obtained sodalite and phosphors. The sodalite Na8(AlSiO4)6(Cl)2 synthesized with 10 mol/L NaOH, 2.3:5 M ratios of metakaolinite:NaCl has good crystallinity and uniform particle size, when the roasting temperature and time was 850 ℃ and 2 h, the roasted samples has product has the best crystallinity and morphology. The Na8(AlSiO4)6(Cl)2:Eu3+ powder obtained with 7 % Eu concentrations had the optimal emission intensity. The photoluminescence properties results revealed that the obtained Na8(AlSiO4)6(Cl)2:Eu3+ phosphors can be excited by 396 nm near-ultraviolet light and emits red light, suggesting promising application in LED lamps matching the excitation of the ultraviolet chip.