Photocatalytic activity of Bi0.8La0.2FeO3-xK0.5Na0.5NbO3 ceramic powders

(1-x)Bi0.8La0.2FeO3-xK0.5Na0.5NbO3) (x = 0.00; 0.05; 0.10, 1.00) or 'BLFO-KNN' was prepared by the combustion method, using KNO3, NaNO3, NH4NbO(C2O4)(2)(H2O)(2), Bi(NO3)center dot 5H(2)O, La(CH3COO)(3) and 5Fe(NO3)(3)center dot 9H(2)O as starting materials. The microstructural features of the synthesized nanoparticles were characterized by X-ray powder diffraction and Raman spectroscopy. Rietveld refinement showed coexistence of orthorhombic-monoclinic phases for the powders obtained with x = 0.05 and 0.10. The photocatalytic activity of the BLFO-KNN, at different pH values, was investigated via degradation of rhodamine 6G (Rh6G) dye in a photoreactor equipped with commercial lamps that simulated sunlight. The results showed that BLFO can absorb visible light, whereas KNN absorbs in the ultraviolet range. There is a strong effect of the pH on the photocatalytic activity, with the highest activity for the Bi0.8La0.2FeO3 system at pH = 2 (similar to 90% degradation efficiency for x = 0.0).