Optical properties of Bi₂Fe₄O₉/Ag₃PO₄ for rapid degradation of Rhodamine B

This work focuses on the synthesis of Bi₂Fe₄O₉/Ag₃PO₄ composites with different Bi₂Fe₄O₉ contents to remove the Rhodamine B (RhB) dye pollutant. The obtained composites were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, Photoluminescence and UV–Vis spectrophotometry. The 5Bi₂Fe₄O₉/Ag₃PO₄ catalyst with 5% Bi₂Fe₄O₉ loading exhibited the high photocatalytic performance with degradation efficiency of 97.91% after 12 min under visible light irradiation. Photoluminescence and UV–Vis analysis showed that 5Bi₂Fe₄O₉/Ag₃PO₄ has the best separation of photogenerated e⁻/h⁺ pairs and light absorption. The catalyst exhibited a good selectivity toward tartrazine and methylene blue. The cycling experiment revealed that 5Bi₂Fe₄O₉/Ag₃PO₄ catalyst has a good stability after 4 runs. The results of trapping radical experiments indicated that h⁺ charge carriers were the main species involved in the RhB photodegradation process which was supported by a Z-scheme electron transfer mechanism.