The photoluminescence properties of tri-colour silicoaluminate phosphors prepared from oil shale ash

In this paper, high value-added tri-colour phosphors Ba0.96Mg1.88Si2O7:0.02Eu(2+), 0.02Dy(3+), 0.12Mn(2+); CaSr0.995SiO4:0.005Eu(2+) and Ba0.91MgAl10O17:0.09Eu(2+) were prepared using the white carbon black (hereinafter referred to as WCB) and alumina extracted from oil shale ash as raw materials. The structure and luminescence properties of the samples were characterized by X-ray diffraction (XRD) and photoluminescent spectra. The results show that the red and green phosphors synthesized by WCB exhibited much weaker emission than the phosphors synthesized by pure chemical reagent silica, which is mainly due to the high content of iron in the WCB. After purifying the WCB under laboratory conditions, the luminescence properties were improved and close to that of pure chemical reagent. By comparing with the emission of the samples synthesized with chemical reagents, the results show that the products extracted from oil shale ash can be applied to synthesize luminescent materials which have potential applications in white-light ultraviolet (UV)-LED field. (C) 2015 Published by Elsevier B.V.