Photocatalytic properties of La-ZnO/Bi₂Fe₄O₉ heterostructures under peroxymonosulfate activation in tetracycline solution degradation

A La-ZnO/Bi₂Fe₄O₉ composite photocatalyst, composed of La-doped ZnO and Bi₂Fe₄O₉ components, was synthesized via hydrothermal synthesis, templating, and calcination processes. An S-scheme charge carrier transfer mechanism (CTM) was identified in the composite system, facilitating efficient charge separation and enhancing photocatalytic activity. The photocatalyst exhibits excellent performance in degrading tetracycline (TC) solution, attributed to the effective separation of photo-generated carriers and the high redox capacity originating from the S-scheme CTM. Furthermore, under the activation of peroxymonosulfate (PMS), its photocatalytic performance is significantly enhanced. Its universality was validated by the efficient degradation of ciprofloxacin (CIP), methyl orange (MO), and rhodamine B (RhB) solutions. Additionally, the photocatalyst demonstrates good stability in both photocatalytic activity and material structure during cyclic degradation experiments. The study highlights the considerable potential of this composite for environmental wastewater treatment applications.