| Long-lasting phosphors have a long decay time in darkness after the removal of the excitation source, ranging from a few minutes to tens of hours.These materials have received increasing interest in recent years due to their good characteristics.There are three major kinds of long afterglow materials. The one is the traditional sulfide long afterglow materials, the other is aluminate phosphors and the last one is silicate long afterglow materials. The traditional sulfide phosphors have several remarkable disadvantages such as chemical stability, poor weathering resistance,a short decay time,harmful to human health and pollution of the environment. Water persistence of the alkaline earth aluminate long afterglow materials is poor. The alkaline earth silicate phosphors as new long afterglow materials overcome the shortcomings of the sulphides and aluminate materiaLAnd high-purity silica material is cheap and easy to get.so the alkaline earth silicate phosphors as new long afterglow is a class of promising materials.One dimensional nanostructured materials due to their special physic and chemical property, unique anisotropic structure,large length to diameter ratio and can applications in nanodevices, electronics, optics and photocatalysts have gained much attention.At present, they are many synthesis approaches to prepare one-dimensional nanostructure, such as hydrothermal, laser ablation, arc discharge and chemical vapor deposition. However, electrospinning is a simple, convenient, effective and versatile method to create various nanofibers.A series of alkaline earth polysilieate phosphors doped with rare earth ions one-dimensional nanofibers were synthesized by a simple and cost-effective electrospinning, XRD, SEM and PL were employed to characterize the samples. According to that, we get some valuable conclusions as follows:1. Blue long afterglow phosphors Sr2MgSi2O7:Eu2+, Dy3+were synthesized by eletrospinning. From the SEM images can be found that the nanofibers with an average diameter of about sereval hundred nanometers. When the calcination temperature is1150℃, produces was single-phase. It is tetragonal,belogs to P-421m(113)space group. According to the JCPDS card, diffraction peaks of nanofibers offset to a large angle, this is because the nanofibers have a large specific surface area, high length-diameter ratio, make the crystal lattice of the nanofibers distortion occurred easier than normal powder, lead to changes in cell parameters. Spectral analysis indicates that this PhosPhor has a broad band emission Peak at471nm, this Peak was made by the transition4f65d’-4f7of Eu2+. Moreover, the optimum concentration of doped Eu2+and Dy3+on the luminescent property are0.03and0.04respectry. 2.The growth mechanism of Sr2MgSi2O7:Eu2+, Dy3+is like this:in the process of annealing at800℃, solvent in the precursor fibers of PVA/[Sr(NO3)2+Mg(NO3)2] evaporating, PVA molecular chains fracturing, burning, decomposition and volatilization. The diameter of the fibers are getting small. With further heating, the precursor fibers continue generating the final producs.3. Bluelong afterglow phosphors SrMgSi2O6:Eu2+, Dy3+were synthesized by eletrospinning. the effects of different concentration of doped Eu2+and Dy3+on the luminescent property were investigated. The results indicate that the doped Eu2+and Dy3+has no influence on the formation of the crystal structure. The optimum doping ratio of Eu3+and Dy3+doped in SrMgSi2O6:Eu2+, Dy3+are3%and3%respecticely. The optimum temperature of synthesis is1050℃. Spectral analysis indicates that this PhosPhor has a broad band emission Peak at471nm, this Peak was made by the transition4f65d1-4f7of Eu2+. SEM analysis indicates that the samples with an average diameter of about sereval hundred nanometers. |
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