Facile Room Temperature Ion Exchange Synthesis Of H+ Doped KM0.33Te1.67O6 (M = Al, Cr And Fe) And Their Photocatalytic And Conductivity Studies

Materials belonging to defect pyrochlore structure have been the subject of considerable interest and expected to exhibit fast protonic conduction. The proton exchanged ternary metal oxides of composition HM0.33Te1.67O6 (M = Al, Cr and Fe) are prepared for the first time by ion exchange method at room temperature. These materials are characterized by X-ray Diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and solid state NMR techniques. All the materials are crystallized in a cubic lattice with the Fd - 3m space group. Photocatalytic activity against methyl violet (MV) degradation under visible light irradiation is studied. The mechanistic degradation pathway of MV is studied by a fluorescence technique using terepthalic acid (TA) as a probe and Tertiary butanol (TB) as hydroxyl radical quencher. The dc conductivity of all three compositions is studied in the temperature range 300 – 673 K. The variation of dc conductivity with temperature is explained.