Acetaminophen oxidation under solar light using Fe-BiOBr as a mild Photo-Fenton catalyst

[Display omitted] •Fe-BiOBr with flower-like shape is synthesized using microwave-assisted solvothermal method.•1Fe-BiOBr has shown a high degradation efficiency during acetaminophen degradation under sunlight.•Mild conditions close to neutral pH and low catalyst loading have been used.•A synergistic reaction mechanism that combines heterogeneous photocatalysis and Fenton processes is proposed. Acetaminophen is an analgesic used as a first-choice treatment for pain and fever. When individuals consume acetaminophen, a portion of the drug is excreted through urine and can end up in wastewater. Water remediation from pharmaceuticals, such as acetaminophen, is required before reaching the environment. This work demonstrates that Fe–BiOBr using the solar photo-Fenton process eliminates acetaminophen at mild pH in aqueous media. Fe-BiOBr is produced using microwave-assisted solvothermal synthesis, and the formation of the BiOBr phase is confirmed with XRD. SEM and TEM demonstrated the flower-like morphology, in which crystallite size reduces as a function of the Fe loading. The chemical environment at the surface of Fe–BiOBr is investigated with XPS. The results are connected with Raman analysis, which suggests the presence of oxygen vacancies in Fe–BiOBr. Furthermore, the effect of Fe in BiOBr is assessed by determining the optical band gap with UV–Vis. The Fe-BiOBr functionality is assessed during acetaminophen degradation. Fe-BiOBr revealed excellent performance in degrading acetaminophen in the first minutes (Q = 10 kJ m−2) under natural sunlight. Results reveal that 1% Fe content in BiOBr can degrade acetaminophen and its main byproduct (30 min, Q = 50 kJ m−2) at pH 5 and using 0.25 gL-1 of catalyst. A synergistic mechanism between heterogeneous photocatalysis and Fenton processes with primary superoxide (•O2–) radical, followed by hydroxyl (•OH) radical and photogenerated holes (h+), is proposed. Our research contributes to the degradation of pharmaceuticals under mild conditions and sunlight irradiation.