Preparation of CaAl2O4:Eu2+, Nd3+ and SrAl2O4:Eu2+, Dy3+ long afterglow luminescent materials using oil shale ash

Abstract In this paper, long afterglow luminescent materials CaAl 2 O 4 :Eu 2+ , Nd 3+ and SrAl 2 O 4 :Eu 2+ , Dy 3+ were successfully synthesized by high temperature solid state reaction using the alumina extracted from oil shale ash. The properties of samples were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF) photoluminescence (PL) spectra, thermoluminescent (TL) curve, long afterglow material optical test system. CaAl 2 O 4 :Eu 2+ , Nd 3+ and SrAl 2 O 4 :Eu 2+ , Dy 3+ prepared with alumina extracted from oil shale ash showed persistent phosphorescence in blue (440 nm) and green (515 nm) with persistence time over 10 h for the blue and 8 h for the green. This result indicates that the alumina extracted from oil shale ash can be used to prepare fluorescent materials. This reuse can not only utilize the oil shale ash rationally but also substantially increased the added-value of oil shale ash.