Preparation, characterization and environmental applications of Sr1 - x (La,Bi) x TiO3 perovskites immobilized on Ni-foam: photodegradation of the Acid Orange 7.

The Sr1 - x La x TiO3 (0 ≤ x ≤ 0.4) and Sr1 - x Bi x TiO3 (0 ≤ x ≤ 0.3) perovskites were prepared via solid state reaction by partially replacing the Sr2+ ions in the SrTiO3 structure by La3+ or Bi3+ ions, characterized and utilized as photocatalysts immobilized in Ni-foam substrate in the degradation of the azo dye Acid Orange 7 (AO7). For both perovskite families, the XRD data reveal the existence of a predominant well-crystallized phase, belonging to a cubic perovskite in a Pm3m space group, with the presence of other minority phases. The characteristic dimension and the volume of the cell decrease with the introduction in the SrTiO3 lattice of the La3+ or Bi3+ ions. The grain size of the Sr1 - x La x TiO3 samples is around 100 nm and slightly lower for the Sr1 - x Bi x TiO3 samples. Regarding the utilization of the prepared perovskite powders deposited over the Ni-foam substrates as catalysts in the photodegradation of AO7 solutions, the results show an improvement in the performance of the films of the substituted perovskite when compared to the SrTiO3 perovskite, being the best results obtained with Sr0.9Bi0.1TiO3.