Porous calcium niobate nanosheets prepared by an exfoliation-restacking route

Water Sci Technol. 2016;73(6):1378-86. doi: 10.2166/wst.2015.610.

Abstract

The single phase layered perovskite-type niobate KCa2Nb3O10 was obtained by a solid state reaction of the starting materials (K2CO3, CaCO3 and Nb2O5) at 1,200 °C. Then the H(+)-exchanged form (HCa2Nb3O10) was successfully exfoliated into colloidal porous single layers on the intercalating action of tetra(butyl)ammonium ion. The various characterization techniques such as X-ray diffraction (XRD), field-emission scanning electron microscopy, N2 absorption-desorption and diffuse reflectance UV-visible spectrometry gave important information on the unusual structural features of the perovskite-related niobate nanosheets. XRD analysis of the exfoliated nanosheets showed a unique profile with wide peaks that represented individual molecular aspects of the nanosheets. The Brunauer-Emmett-Teller isotherm of the exfoliated coiled nanosheets showed a sharp increase in the surface area by a factor of >30 in comparison to parent layered material, which is due to the exfoliation and restacking process. The nanosheets in this study were also found to act as a semiconductor with a wide band gap that is due to the quantum size effect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium Carbonate / chemistry*
  • Carbonates / chemistry*
  • Microscopy, Electron, Scanning
  • Nanostructures / chemistry*
  • Niobium / chemistry*
  • Oxides / chemistry*
  • Porosity
  • Potassium / chemistry*
  • Quaternary Ammonium Compounds / chemistry
  • X-Ray Diffraction

Substances

  • Carbonates
  • Oxides
  • Quaternary Ammonium Compounds
  • Niobium
  • potassium carbonate
  • tetrabutylammonium
  • Calcium Carbonate
  • niobium pentoxide
  • Potassium