Synthesis, characterisation and photocatalytic activity of Ag+- and Sn2+-substituted KSbTeO6

Ag+- and Sn2+-substituted KSbTeO6 were prepared by a facile ion-exchange method at ambient temperature. All the samples were characterised by scanning electron microscopy, energy-dispersive spectra, thermogravimetric analysis, powder X-ray diffraction, Raman spectra and UV-VIS diffuse reflectance spectra. Both Sn2+- and Ag+-substituted KSbTeO6 were crystallised in a cubic lattice with the \(Fd\bar 3m\) space group. The band-gap energy of all the samples was deduced from their UV-VIS diffuse reflectance spectral profiles. The visible light-induced photocatalytic oxidation of the methylene blue (MB) dye was examined in the presence of all the as-prepared materials. The Ag+- and Sn2+-substituted KSbTeO6 exhibited a higher photocatalytic activity than the parent KSbTeO6 in degradation of the MB dye under visible light irradiation.