Preparation and characterization of orthorhombic NaNbO₃ Long Bar

In this study, we successfully prepared perovskite-type NaNbO₃ long bars with orthorhombic phase. At first, one-dimensional sandia octahedral molecular sieves (SOMS) were synthesized by the hydrothermal treatment at 160 °C using Nb₂O₅ and NaOH as the initial reactants. The SOMS exhibited ribbon-like Na₂Nb₂O₆·6/ 5H₂O fiber structures with high length-to-width ratio. Then, the prepared ribbon-like Na₂Nb₂O₆·6/5H ₂O fibers changed into the perovskite structure by the post-heat treatment at 450 °C. The surface morphology and phase structure of the products were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) respectively; the fine structures of the products were investigated by means of Raman spectrum and high-resolution transmission electron microscopy (HRTEM). Furthermore, the mechanism of formation of NaNbO₃ long bars was studied based on the experimental data. Our study may provide a new approach for the preparation and investigation of one-dimensional alkali niobate photocatalytic materials and template grain for textured alkali niobium.