Photoluminescence and phosphorescence from MCM-48 nanoparticle-embedded composite nanofibers prepared by electrospinning

Abstract

MCM-48 nanoparticle-embedded polymer nanofibers (NPNFs) were prepared from the PVP solution containing MCM-48 nanoparticles (NPs) by the electrospinning technique. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS) were used to characterize the composition and morphology of electrospun nanofibers. The results showed that the average diameter of MCM-48 NPNFs was about 500 nm. Photoluminescence (PL) and phosphorescence properties were investigated by fluorescence spectrofluorometer. MCM-48 NPNFs exhibited a bright blue-green emission at ∼420 nm, followed by a long-lifetime blue-green phosphorescence at ∼480 nm, which can be fitted by a bi-exponential decay process with lifetimes of 3.24 s and 1.22 s at room temperature. The triplet-to-singlet transition is responsible for the blue-green emission around 420 nm of the MCM materials, while the phosphorescence at ∼480 nm is probably due to the oxygen-related vacancies on the surface, which act as a capture trap.