Synthesis, Characterization and Photocatalytic Activity of Ag+ - and Sn2+ -Doped KTi0.5 Te1.5 O6.

Abstract

In this study, the photocatalytic dye degradation efficiency of KTi0.5 Te1.5 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 KTi0.5 Te1.5 O6 materials obtained from DRS profiles were found to be 2.96, 2.55 and 2.40eV, 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 KTi0.5 Te1.5 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 KTi0.5 Te1.5 O6 . The mechanistic degradation pathway of methylene blue (MB) was studied in the presence of Sn2+ -doped KTi0.5 Te1.5 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.