Mannepalli Sudheera; Perala Venkataswamy; Gundeboina Ravi; Kadari Ramaswamy; Nalluri Chitti Babu; Muga Vithal
Abstract
Anion doping is one of the efficient ways to tailor the bandgap of photocatalysts for the treatment of polluted water. The present work describes the improved photocatalytic activity of defect pyrochlore, KTaTeO6 (KTTO), upon nitrogen doping, towards the degradation of methylene blue under visible light ...
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Anion doping is one of the efficient ways to tailor the bandgap of photocatalysts for the treatment of polluted water. The present work describes the improved photocatalytic activity of defect pyrochlore, KTaTeO6 (KTTO), upon nitrogen doping, towards the degradation of methylene blue under visible light irradiation. The parent KTaTeO6 was synthesized by solid-state method. The N-doped KTaTeO6 (N-KTTO) was prepared by nitridation method using NH3. Techniques such as the XRD, N2 adsorption-desorption, FE-SEM/EDX/EDS elemental mapping, TEM-HRTEM, UV-Vis DRS, XPS, Raman, and PL were employed to characterize the physicochemical properties of photocatalysts. The N-doping in KTTO has resulted in enlarged surface area, narrowed the bandgap, and reduced the recombination of photogenerated electron-hole pairs, leading to enhanced photocatalytic activity compared to parent KTTO. The active species trapping experiments were conducted to elucidate the mechanism of photodegradation. The N-KTTO is chemically stable and can be used at least up to five cycles.
Ravinder Guje; G.Ravi;M. Vithal; J.R. Reddy; Ch. Sudhakar Reddy; K. Sreenu; G.Ravi and M. Vithal
Abstract
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 ...
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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.
