Bi₂Fe₄O₉ in pellet form is an alternative in the wastewater treatment process

This study aimed to synthesize Bi₂Fe₄O₉ and apply it to the degradation of tartrazine yellow dye. Bi₂Fe₄O₉ was synthesized using the solid-state reaction and the Pechini method. The materials obtained were characterized using X-ray diffraction (XRD), visible ultraviolet spectroscopy (UV-Vis) and field emission scanning electron microscopy (FEG). The microscopic images revealed a morphological difference between the two materials in which the material obtained by the Pechini method is the most porous and have the largest surface area. The pellet obtained by the Pechini method was seen to have a lower bandgap value when compared with the sample solid state reaction. In the photocatalysis tests, the best performance was also that of the material obtained by the Pechini method, with 99.34% degradation, while the material obtained by solid state reaction showed 85.86% in 120 minutes. The solution degraded with the material obtained by the Pechini method presented 81.66% of mineralization while the solution with the material obtained by solid state reaction showed 60.97% of mineralization. The results confirmed that the material obtained by both syntheses is able to maintain its effectiveness after 10 repetitions of the photocatalytic process, proving to be promising for waste treatment in the industrial field.