High-Pressure Polymorph of NaBiO3.

A new high-pressure polymorph of NaBiO3 (hereafter β-NaBiO3) was synthesized under the conditions of 6 GPa and 600 °C. The powder X-ray diffraction pattern of this new phase was indexed with a hexagonal cell of a = 9.968(1) Å and c = 3.2933(4) Å. Crystal structure refinement using synchrotron powder X-ray diffraction data led to RWP = 8.53% and RP = 5.55%, and the crystal structure was closely related with that of Ba2SrY6O12. No photocatalytic activity for phenol decomposition was observed under visible-light irradiation in spite of a good performance for its mother compound, NaBiO3. The optical band-gap energy of β-NaBiO3 was narrower than that of NaBiO3, which was confirmed with density of states curves simulated by first-principles density functional theory calculation.

[1]  V. Cuenca-Gotor,et al.  Pressure-induced phase transition and band-gap collapse in the wide-band-gap semiconductor InTaO4 , 2016, 1610.06739.

[2]  C. Moriyoshi,et al.  Hydrothermal synthesis and crystal structure analysis of two new cadmium bismuthates, CdBi2O6 and Cd0.37Bi0.63O1.79 , 2015 .

[3]  M. Bettinelli,et al.  Theoretical and Experimental Study of the Crystal Structures, Lattice Vibrations, and Band Structures of Monazite-Type PbCrO4, PbSeO4, SrCrO4, and SrSeO4. , 2015, Inorganic chemistry.

[4]  T. Takei,et al.  Preparation and photocatalytic properties of new calcium and lead bismuthates , 2014 .

[5]  M. Avdeev,et al.  The ferroelectric phase of CdTiO3: A powder neutron diffraction study , 2011 .

[6]  Q. Dong,et al.  Photocatalytic activities of various pentavalent bismuthates under visible light irradiation , 2011 .

[7]  S. Ashbrook,et al.  Control of polymorphism in NaNbO(3) by hydrothermal synthesis. , 2009, Chemical communications.

[8]  Fujio Izumi,et al.  VESTA: a three-dimensional visualization system for electronic and structural analysis , 2008 .

[9]  F. Izumi,et al.  Three-Dimensional Visualization in Powder Diffraction , 2007 .

[10]  Jinhua Ye,et al.  Decomposition of organic compounds over NaBiO3 under visible light irradiation , 2007 .

[11]  Song-Ho Byeon,et al.  Polymorphism in NaSbO3: structure and bonding in metal oxides. , 2004, Journal of the American Chemical Society.

[12]  A. Sleight,et al.  Neutron powder diffraction refinement of ilmenite-type bismuth oxides : ABiO3 (A = Na, Ag) , 2000 .

[13]  A. Sleight,et al.  Preparation of ABi2O6 (A = Mg, Zn) with the trirutile-type structure , 1997 .

[14]  M. Greenblatt,et al.  The Crystal Structure and Ionic Conductivity of the Ilmenite Polymorph of NaSbO3 , 1994 .

[15]  N. Kumada,et al.  Crystal Structures of Ilmenite Type LiNbO3 and NaNbO3 , 1990 .

[16]  N. Kinomura,et al.  A new allotropic form with ilmenite-type structure of NaNbO3 , 1984 .

[17]  H. Müller-Buschbaum,et al.  Notizen: Über Erdalkalimetalloxogallate, IX Zum Aufbau von β-SrGa2O4/ Oxogallates of Alkaline Earth Metals, IX The Structure of β-SrGa2O4 , 1981 .

[18]  R. D. Shannon.  Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides , 1976 .

[19]  H. Haraldsen,et al.  X-Ray Studies on "Sodium Metabismuthate". , 1955 .

[20]  T. Barth,et al.  Notes on some Structures of the Ilmenite Type , 1934 .