title: Porous calcium niobate nanosheets prepared by an exfoliation-restacking route.
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.
authors.affiliation: Young Researchers and Elite Club, Marand Branch, Islamic Azad University, Marand, Iran E-mail: Fa.hashemzadeh@gmail.com.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Hashemzadeh
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry*; D009556:Niobium / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D016062:Porosity; D011188:Potassium / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D002254:Carbonates; D010087:Oxides; D000644:Quaternary Ammonium Compounds; D009556:Niobium; C037593:potassium carbonate; C009405:tetrabutylammonium; D002119:Calcium Carbonate; C073337:niobium pentoxide; D011188:Potassium