Synthesis and visible light photocatalytic properties of Bi₂Fe₄O₉ particles via EDTA-assisted sol–gel route

Submicron Bi₂Fe₄O₉ particles could be obtained by applying a modified sol–gel synthesis at the temperature of 650 °C, with ethylenediaminetetraacetic acid (EDTA) as chelating agent. SEM images showed that morphology and grain size of the as-prepared powders were influenced by calcination temperature. Bi₂Fe₄O₉ pure phase could be controlled by adjusting the amount of EDTA. Correspondingly, the crystal growth and morphology evolution mechanism in the reactions were discussed. Additionally, the photocatalytic properties of the particles were explored. The Bi₂Fe₄O₉ particles synthesized with 5 mmol EDTA showed the highest photocatalytic activity toward methyl orange and rhodamine-B degradation under visible light irradiation, the degradation rate could be as high as 93 and 99 % in 3 h with the aid of H₂O₂, respectively.