Crystal structures and photocatalysis of the triclinic polymorphs of BiNbO4 and BiTaO4

B. Muktha (1) , Jacques Darriet (2) , Giridhar Madras (3) , T. N. Guru Row (1)

1 Solid State and Structural Chemistry Unit
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 Department of Chemical Engineering

The high-temperature polymorphs of two photocatalytic materials, BiNbO4 and BiTaO4 were synthesized by the ceramic method. The crystal structures of these materials were determined by single-crystal X-ray diffraction. BiNbO4 and BiTaO4 crystallize into the triclinic system P1¯ (No. 2), with a=5.5376(4) Å, b=7.6184(3) Å, c=7.9324(36) Å, α=102.565(3)°, β=90.143(2)°, γ=92.788 (4)°, V=326.21 (5) Å3, Z=4 and a=5.931 (1) Å, b=7.672 (2) Å, c=7.786 (2) Å, α=102.94 (3)°, β=90.04 (3)° γ=93.53 (3)°, V=344.59 (1) Å3 and Z=4, respectively. The structures along the c-axis, consist of layers of [Bi2O2] units separated by puckered sheets of (Nb/Ta)O6 octahedra. Photocatalytic studies on the degradation of dyes indicate selectivity of BiNbO4 towards aromatics containing quinonic and azo functional groups.

Mots clés: Single-crystal X-ray diffraction; Crystal structure; Bismuth niobate; Bismuth tantalate; Photocatalysis

Domaines: Matériaux

B. Muktha, Jacques Darriet, Giridhar Madras, T. N. Guru Row. Crystal structures and photocatalysis of the triclinic polymorphs of BiNbO4 and BiTaO4. Journal of Solid State Chemistry, 2006, 179 (12), pp.3919-3925. ⟨10.1016/j.jssc.2006.08.032⟩. ⟨hal-00123251⟩