Effect of the Synthesis Method on the Composition, Morphology, and Catalytic Properties of Nanosized Bismuth Ferrite

Nanocrystalline bismuth ferrite was synthesized using spray pyrolysis and citrate combustion methods. BiFeO₃ samples were characterized by X-ray diffraction, infrared spectroscopy, scanning and transmission electron microscopy, and energy dispersive X-ray spectroscopy. The citrate and spray pyrolysis samples of bismuth ferrite were tested as catalysts for the Fenton-like oxidative degradation of methyl orange. The effect of the synthesis method on the composition and morphology of bismuth ferrite particles and on the catalytic activity was established. The oxidative degradation of the dye in the presence of bismuth ferrite samples is satisfactorily described by pseudo-first order kinetics. The reaction rate constant for BiFeO₃ synthesized by spray pyrolysis is 0.0072 min^–1, while that for citrate BiFeO₃ is slightly lower: 0.0049 min^–1. The degree of degradation of methyl orange in 120 min is 7% without a catalyst, 62% in the presence of spray pyrolysis bismuth ferrite, and 51% in the presence of citrate bismuth ferrite.