Synthesis, Characterization and Photocatalytic Activity of Ag⁺ - and Sn²⁺ -Doped KTi_0.5 Te_1.5 O₆

In this study, the photocatalytic dye degradation efficiency of KTi_0.5 Te_1.5 O₆ synthesized through solid-state method was enhanced by cation (Ag⁺ /Sn⁺² ) doping at potassium site via ion exchange method. As prepared materials were characterized by XRD, SEM-EDS, IR, TGA and UV-Vis Diffuse reflectance spectroscopic (DRS) techniques. All the compounds were crystallized in cubic lattice with Fd3¯m space group. The bandgap energies of parent, Ag⁺ - and Sn⁺² -doped KTi_0.5 Te_1.5 O₆ materials obtained from DRS profiles were found to be 2.96, 2.55 and 2.40 eV, respectively. Photocatalytic efficiency of parent, Ag⁺ - and Sn⁺² -doped materials was evaluated against the degradation of methylene blue (MB) and methyl violet (MV) dyes under visible light irradiation. The Sn⁺² -doped KTi_0.5 Te_1.5 O₆ showed higher activity toward the degradation of both MB and MV dyes and its higher activity is ascribed to the lower bandgap energy compared to the parent and Ag⁺ -doped KTi_0.5 Te_1.5 O₆ . The mechanistic degradation pathway of methylene blue (MB) was studied in the presence of Sn²⁺ -doped KTi_0.5 Te_1.5 O₆ . Quenching experiments were performed to know the participation of holes, super oxide and hydroxyl radicals in the dye degradation process. The stability and reusability of the catalysts were studied.