Effect of bismuth substitution on crystal chemistry, photocatalysis and conductivity in Sr3V2O8: a new structural type in palmierite class

Abstract

The effect of Bi substitution has been investigated in the palmierite type system Sr₃V₂O₈, wherein, a new solid solution Sr_3−xBi_2x/3V₂O₈ (0 ≤ x ≤ 0.4) has been established. The structure of the composition x = 0.20 (Sr_2.8Bi_0.13V₂O₈) was solved using single-crystal X-ray diffraction (XRD) technique. The compound crystallizes in the trigonal crystal system Rm with a palmierite structural type with a = 5.6067(4) Å, c = 20.0099(13) Å, V = 580.64(5) ų and Z = 3. The substituent Bi occupies a new unique 18h site resulting in a new series in palmierite class of compounds. The new solid solution has been characterized by synchrotron X-ray powder diffraction, solid-state UV-Vis diffuse-reflectance spectra, scanning electron microscopy and ionic conductivities and photocatalytic activities has been investigated. The solid solution compounds exhibited photocatalytic activity towards various classes of anionic dyes under UV radiation.