Nanostructured KTaTeO6 and Ag-doped KTaTeO6 Defect Pyrochlores: Promising Photocatalysts for Dye Degradation and Water Splitting

• Published in: Electronic materials letters 2018-07, Vol.14 (4), p.446-460
• Main Authors: Venkataswamy, Perala, Sudhakar Reddy, CH, Gundeboina, Ravi, Sadanandam, Gullapelli, Veldurthi, Naveen Kumar, Vithal, M.
• Format: Article
• Language: English
• Subjects: Catalytic activity; Characterization and Evaluation of Materials; Chemical composition; Chemical synthesis; Chemistry and Materials Science; Condensed Matter Physics; Degradation; Electromagnetic absorption; Energy gap; Hydroxyl groups; Ion exchange; Materials Science; Morphology; Nanostructure; Nanotechnology; Nanotechnology and Microengineering; Optical and Electronic Materials; Organic chemistry; Photocatalysis; Pyrochlores; Silver; Surface area; Surface chemistry; Water splitting
• ISSN: 1738-8090; 2093-6788
• DOI: 10.1007/s13391-018-0055-9

In this study, the nanostructured parent KTaTeO 6 (KTTO) and Ag-doped KTaTeO 6 (ATTO) catalysts with defect pyrochlore structure were prepared by solid-state and ion-exchange methods, respectively. The synthesized materials were characterized by various techniques to determine their chemical composition, morphology and microstructural features. The XRD studies show that both KTTO and ATTO have cubic structure (space group Fd3m ) with high crystallinity. The doping of Ag altered the BET surface area of parent KTTO. The nano nature of the samples was studied by TEM images. A considerable red-shift in the absorption edge is observed for ATTO compared to KTTO. Incorporation of Ag + in the KTTO lattice is clearly identified from EDX, elemental mapping and XPS results. Degradation of methyl violet and solar water splitting reactions were used to access the photocatalytic activity of KTTO and ATTO. The results obtained suggest that compared to KTTO, the ATTO showed higher photocatalytic activity in both cases. The favourable properties such as high surface area, more surface hydroxyl groups, stronger light absorption in visible region and narrower band gap energy were supposed to be the reasons for the high activity observed in ATTO.