Length-controlled synthesis and the photoluminescence of pre-perovskite PbTiO3 nanofibers
A novel approach that combines a modified sol–gel process with a PVA-assisted hydrothermal reaction at 200 °C for 12 h has been developed to prepare single-crystal pre-perovskite PbTiO3 nanofibers with good dispersity and length control. By increasing the dosage of triethanolamine (TEA) solution into the Ti precursor to modify the sol–gel process, the length of the nanofibers in the prepared samples decreased from about 35–90 μm to 5–12 μm, whereas the corresponding diameter remained in the range of 100–300 nm. Further, the dispersity of the samples, as well as the diameter uniformity of a single nanofiber, was improved significantly. In particular, a broad green photoluminescence (PL) emission (~550 nm) was observed in the nanofibers at room temperature. It is interesting to find that no obvious size effect was detected on the green PL emission.