Realizing single-crystalline vertically-oriented and high-density electrospun nanofibril bundles by controlled postcalcination

Abstract

For the first time, single-crystal (SC), vertically-oriented and high-density electrospun ultrafine nanofiber/fibre bundles (NFBs) were achieved by the controlled postcalcination of as-spun fibers. The formation of high-density SC strontium carbonate (i.e. SrCO₃) nanoneedles (NNs) quasi-vertically grown with an average diameter of ∼20 nm, several micrometers long that stand perpendicular to the growth surface, is demonstrated. Furthermore, under electron-beam irradiation, an individual as-calcined SC SrCO₃ NN undergoes sequential structural transitions from the [110] SC—to—polycrystalline—to—[102] SC SrCO₃ NN, which was revealed by in situ transmission electron microscopy. Photoluminescence quenching over the full solar spectrum range was observed in the as-calcined vertically-oriented SrCO₃ NFBs.