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

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 dem-onstrates 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 perfor-mance 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 (center dot O2-) radical, followed by hydroxyl (center dot OH) radical and photogenerated holes (h+), is proposed. Our research contributes to the degradation of pharmaceuticals under mild conditions and sunlight irradiation.