A Novel Scheme to Obtain Y2O2S:Er3+ Upconversion Luminescent Hollow Nanofibers via Precursor Templating

Y2O3:Er3+ hollow nanofibers were prepared by calcination of the monoaxial electrospinning‐derived PVP/[Y(NO3)3+Er(NO3)3] composite nanofibers, and then Y2O2S:Er3+ hollow nanofibers were synthesized by sulfurization of the as‐obtained Y2O3:Er3+ hollow nanofibers via a double‐crucible method using sulfur powders as sulfur source. X‐ray diffraction (XRD) analysis shows that the Y2O2S:Er3+ hollow nanofibers are pure hexagonal phase with the space group of P3¯m1. Scanning electron microscope (SEM) observation indicates that the Y2O2S:Er3+ hollow nanofibers are obvious hollow‐centered with the outer diameter of 176 ± 25 nm. Upconversion emission spectrum analysis manifests that Y2O2S:Er3+ hollow nanofibers emit strong green and weak red upconversion emissions centering at 526, 546, and 667 nm, respectively. The green emissions and the red emission are, respectively, originated from 2H11/2/4S3/2→4I15/2 and 4F9/2→4Il5/2 energy levels transitions of the Er3+ ions. The emitting colors of Y2O2S:Er3+ hollow nanofibers are located in the green region in CIE chromaticity coordinates diagram. The formation mechanism of the Y2O2S:Er3+ hollow nanofibers is also advanced. This preparation technique can be applied to prepare other rare‐earth oxysulfides hollow nanofibers.