Sol–gel synthesis of Sm2InTaO7 and its photocatalytic activity on degradation of crystal violet dye and reduction of Cr(VI) ions

This paper reports the synthesis of Sm 2 InTaO 7 and its photocatalytic activity on the degradation of crystal violet dye and reduction of Cr(VI) ions in aqueous solution. Sm 2 InTaO 7 was prepared by sol–gel method at 1,200 °C. For comparison purposes, Sm 2 InTaO 7 was prepared also by solid-state reaction at 1,400 °C. The evolution of the crystalline phases of the sol–gel sample with the annealing temperature was followed by X-ray diffraction. The cubic crystalline structure of Sm 2 InTaO 7 was determined by Rietveld refinement method. Specific surface area was 5 m 2 g −1 for sol–gel sample and 1 m 2 g −1 for solid-state sample, whereas energy band gap was around 3.5 eV. Sm 2 InTaO 7 prepared by sol–gel method showed better photocatalytic activity than Sm 2 InTaO 7 prepared by solid-state reaction for the mineralization of crystal violet dye and reduction of Cr(VI) solution under UV-light irradiation.