Ex Situ Method for Photoreduction of the Cadmium Ion from Terbium-Loaded Bismuth Vanadium Oxide

[Image: see text] The photoreduction of Cd (II) to Cd (0) was performed using Bi(4)V(2)O(11), which was tremendously enhanced by Tb(3+)-doped Bi(4)V(2)O(11). The relationship between charge carrier isolation and light harvesting was studied in depth in this research, and a promising technique for fabricating effective photocatalysts for heavy metals was discovered. Lattice disorder effects due to size variance between V(5+) and Tb(3+) cations in Bi(4)V(2)O(11) nanomaterials substituted with an invariable Tb(3+) cation at different concentrations (x = 15, 20, and 25%). Bi(4)V(2)O(11) and 15% Tb/Bi(4)V(2)O(11) evidenced a coexistence of monoclinic (α-phase) with a CS/m symmetry, while 25% Tb/Bi(4)V(2)O(11) was tetragonal (γ-phase) with an I4/mmm symmetry. Raman scattering experiments elucidated the changes in Bi(4)V(2)O(11) lattice corresponding to oxygen motion, suggesting significant destabilization of the VO(4) tetrahedra after addition of Tb(3+). The SEM micrograph depicted a disparity in the microstructure with reduced grain size in 25% Tb/Bi(4)V(2)O(11) samples. However, the TEM micrographs of 25% Tb/Bi(4)V(2)O(11) nanomaterials revealed that crystallite sizes of 25–35 nm were obtained, presenting a single tetragonal phase, highly homogeneous in nature. Impedance spectroscopy was used to study the conductivity of these compounds in the temperature range of 300 °C. At 300 °C, the compounds with x = 25% showed a conductivity of 15.92 S cm(–1). The conductivity values were found to be comparable with the highest values reported in the literature for similar compounds.